[PATCH v1 00/15] powerpc: Add KUAP support for BOOKE and 40x

[PATCH v1 00/15] powerpc: Add KUAP support for BOOKE and 40x

[Christophe Leroy]

On booke/40x we don't have segments like book3s/32.
On booke/40x we don't have access protection groups like 8xx.

Use the PID register to provide user access protection.
Kernel address space can be accessed with any PID.
User address space has to be accessed with the PID of the user.
User PID is always not null.

Everytime the kernel is entered, set PID register to 0 and
restore PID register when returning to user.

Everytime kernel needs to access user data, PID is restored
for the access.

In TLB miss handlers, check the PID and bail out to data storage
exception when PID is 0 and accessed address is in user space.

Note that also forbids execution of user text by kernel except
when user access is unlocked. But this shouldn't be a problem
as the kernel is not supposed to ever run user text.

This series has:
- Two first patches have already been submitted and are not directly related to KUAP but would conflict otherwise
- Following patches aim at refactoring the KUAP interface to reduce redundant platform specific code.
- Then comes patches 9 and 10 that add generic support frame for booke type processors
- Followed by the assembly modification for each of the 4 booke family types 

Christophe Leroy (15):
  powerpc/32s: Do kuep_lock() and kuep_unlock() in assembly
  powerpc/32s: Save content of sr0 to avoid 'mfsr'
  powerpc/kuap: Add a generic intermediate layer
  powerpc/kuap: Check KUAP activation in generic functions
  powerpc/kuap: Remove __kuap_assert_locked()
  powerpc/kuap: Add kuap_lock()
  powerpc/nohash: Move setup_kuap out of 8xx.c
  powerpc/config: Add CONFIG_BOOKE_OR_40x
  powerpc/kuap: Prepare for supporting KUAP on BOOK3E/64
  powerpc: Add KUAP support for BOOKE and 40x
  powerpc/kuap: Wire-up KUAP on 44x
  powerpc/kuap: Wire-up KUAP on 40x
  powerpc/kuap: Wire-up KUAP on 85xx in 32 bits mode.
  powerpc/kuap: Wire-up KUAP on book3e/64
  powerpc: Remove CONFIG_PPC_HAVE_KUAP

 arch/powerpc/include/asm/book3s/32/kup.h      | 103 ++++------------
 arch/powerpc/include/asm/book3s/32/mmu-hash.h |  78 +++++++++++-
 arch/powerpc/include/asm/book3s/64/kup.h      |  56 ++++-----
 arch/powerpc/include/asm/hw_irq.h             |   8 +-
 arch/powerpc/include/asm/interrupt.h          |  13 +-
 arch/powerpc/include/asm/irq.h                |   2 +-
 arch/powerpc/include/asm/kup.h                | 114 +++++++++++++++---
 arch/powerpc/include/asm/nohash/32/kup-8xx.h  |  50 ++------
 arch/powerpc/include/asm/nohash/kup-booke.h   | 110 +++++++++++++++++
 arch/powerpc/include/asm/processor.h          |   4 +
 arch/powerpc/include/asm/ptrace.h             |   2 +-
 arch/powerpc/include/asm/reg.h                |   4 +-
 arch/powerpc/kernel/asm-offsets.c             |   2 +-
 arch/powerpc/kernel/entry_32.S                |  34 +++++-
 arch/powerpc/kernel/head_32.h                 |   6 +
 arch/powerpc/kernel/head_40x.S                |   8 ++
 arch/powerpc/kernel/head_44x.S                |  16 +++
 arch/powerpc/kernel/head_fsl_booke.S          |  12 ++
 arch/powerpc/kernel/interrupt.c               |   3 +-
 arch/powerpc/kernel/irq.c                     |   2 +-
 arch/powerpc/kernel/kgdb.c                    |   4 +-
 arch/powerpc/kernel/process.c                 |   9 +-
 arch/powerpc/kernel/setup.h                   |   2 +-
 arch/powerpc/kernel/setup_32.c                |   2 +-
 arch/powerpc/kernel/time.c                    |   2 +-
 arch/powerpc/mm/book3s32/kuap.c               |   5 +-
 arch/powerpc/mm/book3s32/kuep.c               |  21 +++-
 arch/powerpc/mm/book3s32/mmu_context.c        |  15 ++-
 arch/powerpc/mm/mmu_context.c                 |   9 ++
 arch/powerpc/mm/nohash/8xx.c                  |  21 ----
 arch/powerpc/mm/nohash/Makefile               |   2 +-
 arch/powerpc/mm/nohash/kup.c                  |  31 +++++
 arch/powerpc/mm/nohash/mmu_context.c          |   6 +-
 arch/powerpc/mm/nohash/tlb_low_64e.S          |  40 +++++-
 arch/powerpc/platforms/Kconfig.cputype        |  12 +-
 35 files changed, 571 insertions(+), 237 deletions(-)
 create mode 100644 arch/powerpc/include/asm/nohash/kup-booke.h
 create mode 100644 arch/powerpc/mm/nohash/kup.c

-- 
2.31.1

[PATCH v1 00/15] powerpc: Add KUAP support for BOOKE and 40x

[Christophe Leroy]

On booke/40x we don't have segments like book3s/32.
On booke/40x we don't have access protection groups like 8xx.

Use the PID register to provide user access protection.
Kernel address space can be accessed with any PID.
User address space has to be accessed with the PID of the user.
User PID is always not null.

Everytime the kernel is entered, set PID register to 0 and
restore PID register when returning to user.

Everytime kernel needs to access user data, PID is restored
for the access.

In TLB miss handlers, check the PID and bail out to data storage
exception when PID is 0 and accessed address is in user space.

Note that also forbids execution of user text by kernel except
when user access is unlocked. But this shouldn't be a problem
as the kernel is not supposed to ever run user text.

This series has:
- Two first patches have already been submitted and are not directly related to KUAP but would conflict otherwise
- Following patches aim at refactoring the KUAP interface to reduce redundant platform specific code.
- Then comes patches 9 and 10 that add generic support frame for booke type processors
- Followed by the assembly modification for each of the 4 booke family types 

Christophe Leroy (15):
  powerpc/32s: Do kuep_lock() and kuep_unlock() in assembly
  powerpc/32s: Save content of sr0 to avoid 'mfsr'
  powerpc/kuap: Add a generic intermediate layer
  powerpc/kuap: Check KUAP activation in generic functions
  powerpc/kuap: Remove __kuap_assert_locked()
  powerpc/kuap: Add kuap_lock()
  powerpc/nohash: Move setup_kuap out of 8xx.c
  powerpc/config: Add CONFIG_BOOKE_OR_40x
  powerpc/kuap: Prepare for supporting KUAP on BOOK3E/64
  powerpc: Add KUAP support for BOOKE and 40x
  powerpc/kuap: Wire-up KUAP on 44x
  powerpc/kuap: Wire-up KUAP on 40x
  powerpc/kuap: Wire-up KUAP on 85xx in 32 bits mode.
  powerpc/kuap: Wire-up KUAP on book3e/64
  powerpc: Remove CONFIG_PPC_HAVE_KUAP

 arch/powerpc/include/asm/book3s/32/kup.h      | 103 ++++------------
 arch/powerpc/include/asm/book3s/32/mmu-hash.h |  78 +++++++++++-
 arch/powerpc/include/asm/book3s/64/kup.h      |  56 ++++-----
 arch/powerpc/include/asm/hw_irq.h             |   8 +-
 arch/powerpc/include/asm/interrupt.h          |  13 +-
 arch/powerpc/include/asm/irq.h                |   2 +-
 arch/powerpc/include/asm/kup.h                | 114 +++++++++++++++---
 arch/powerpc/include/asm/nohash/32/kup-8xx.h  |  50 ++------
 arch/powerpc/include/asm/nohash/kup-booke.h   | 110 +++++++++++++++++
 arch/powerpc/include/asm/processor.h          |   4 +
 arch/powerpc/include/asm/ptrace.h             |   2 +-
 arch/powerpc/include/asm/reg.h                |   4 +-
 arch/powerpc/kernel/asm-offsets.c             |   2 +-
 arch/powerpc/kernel/entry_32.S                |  34 +++++-
 arch/powerpc/kernel/head_32.h                 |   6 +
 arch/powerpc/kernel/head_40x.S                |   8 ++
 arch/powerpc/kernel/head_44x.S                |  16 +++
 arch/powerpc/kernel/head_fsl_booke.S          |  12 ++
 arch/powerpc/kernel/interrupt.c               |   3 +-
 arch/powerpc/kernel/irq.c                     |   2 +-
 arch/powerpc/kernel/kgdb.c                    |   4 +-
 arch/powerpc/kernel/process.c                 |   9 +-
 arch/powerpc/kernel/setup.h                   |   2 +-
 arch/powerpc/kernel/setup_32.c                |   2 +-
 arch/powerpc/kernel/time.c                    |   2 +-
 arch/powerpc/mm/book3s32/kuap.c               |   5 +-
 arch/powerpc/mm/book3s32/kuep.c               |  21 +++-
 arch/powerpc/mm/book3s32/mmu_context.c        |  15 ++-
 arch/powerpc/mm/mmu_context.c                 |   9 ++
 arch/powerpc/mm/nohash/8xx.c                  |  21 ----
 arch/powerpc/mm/nohash/Makefile               |   2 +-
 arch/powerpc/mm/nohash/kup.c                  |  31 +++++
 arch/powerpc/mm/nohash/mmu_context.c          |   6 +-
 arch/powerpc/mm/nohash/tlb_low_64e.S          |  40 +++++-
 arch/powerpc/platforms/Kconfig.cputype        |  12 +-
 35 files changed, 571 insertions(+), 237 deletions(-)
 create mode 100644 arch/powerpc/include/asm/nohash/kup-booke.h
 create mode 100644 arch/powerpc/mm/nohash/kup.c

-- 
2.31.1

[PATCH v1 01/15] powerpc/32s: Do kuep_lock() and kuep_unlock() in assembly

[Christophe Leroy]

When interrupt and syscall entries where converted to C, KUEP locking
and unlocking was also converted. It improved performance by unrolling
the loop, and allowed easily implementing boot time deactivation of
KUEP.

However, null_syscall selftest shows that KUEP is still heavy
(361 cycles with KUEP, 212 cycles without).

A way to improve more is to group 'mtsr's together, instead of
repeating 'addi' + 'mtsr' several times.

In order to do that, more registers need to be available. In C, GCC
will always be able to provide the requested number of registers, but
at the cost of saving some data on the stack, which is counter
performant here.

So let's do it in assembly, when we have full control of which
register can be used. It also has the advantage of locking earlier
and unlocking later and it helps GCC generating less tricky code.
The only drawback is to make boot time deactivation less straight
forward and require 'hand' instruction patching.

Group 'mtsr's by 4.

With this change, null_syscall selftest reports 336 cycles. Without
the change it was 361 cycles, that's a 7% reduction.

For the time being, capability to deactivate at boot time is disabled.
It will be re-enabled in following patch.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/book3s/32/kup.h      | 34 --------
 arch/powerpc/include/asm/book3s/32/mmu-hash.h | 77 ++++++++++++++++++-
 arch/powerpc/include/asm/interrupt.h          |  6 +-
 arch/powerpc/include/asm/kup.h                |  5 --
 arch/powerpc/kernel/entry_32.S                | 31 ++++++++
 arch/powerpc/kernel/head_32.h                 |  6 ++
 arch/powerpc/kernel/interrupt.c               |  3 -
 arch/powerpc/mm/book3s32/kuep.c               |  7 +-
 8 files changed, 121 insertions(+), 48 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h
index d4b145b279f6..f159efd04ebc 100644
--- a/arch/powerpc/include/asm/book3s/32/kup.h
+++ b/arch/powerpc/include/asm/book3s/32/kup.h
@@ -24,40 +24,6 @@ static __always_inline bool kuep_is_disabled(void)
 	return !IS_ENABLED(CONFIG_PPC_KUEP) || static_branch_unlikely(&disable_kuep_key);
 }
 
-static inline void kuep_lock(void)
-{
-	if (kuep_is_disabled())
-		return;
-
-	update_user_segments(mfsr(0) | SR_NX);
-	/*
-	 * This isync() shouldn't be necessary as the kernel is not excepted to
-	 * run any instruction in userspace soon after the update of segments,
-	 * but hash based cores (at least G3) seem to exhibit a random
-	 * behaviour when the 'isync' is not there. 603 cores don't have this
-	 * behaviour so don't do the 'isync' as it saves several CPU cycles.
-	 */
-	if (mmu_has_feature(MMU_FTR_HPTE_TABLE))
-		isync();	/* Context sync required after mtsr() */
-}
-
-static inline void kuep_unlock(void)
-{
-	if (kuep_is_disabled())
-		return;
-
-	update_user_segments(mfsr(0) & ~SR_NX);
-	/*
-	 * This isync() shouldn't be necessary as a 'rfi' will soon be executed
-	 * to return to userspace, but hash based cores (at least G3) seem to
-	 * exhibit a random behaviour when the 'isync' is not there. 603 cores
-	 * don't have this behaviour so don't do the 'isync' as it saves several
-	 * CPU cycles.
-	 */
-	if (mmu_has_feature(MMU_FTR_HPTE_TABLE))
-		isync();	/* Context sync required after mtsr() */
-}
-
 #ifdef CONFIG_PPC_KUAP
 
 #include <linux/sched.h>
diff --git a/arch/powerpc/include/asm/book3s/32/mmu-hash.h b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
index f5be185cbdf8..e2f7ccc13edb 100644
--- a/arch/powerpc/include/asm/book3s/32/mmu-hash.h
+++ b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
@@ -64,7 +64,82 @@ struct ppc_bat {
 #define SR_KP	0x20000000	/* User key */
 #define SR_KS	0x40000000	/* Supervisor key */
 
-#ifndef __ASSEMBLY__
+#ifdef __ASSEMBLY__
+
+#include <asm/asm-offsets.h>
+
+.macro uus_addi sr reg1 reg2 imm
+	.if NUM_USER_SEGMENTS > \sr
+	addi	\reg1,\reg2,\imm
+	.endif
+.endm
+
+.macro uus_mtsr sr reg1
+	.if NUM_USER_SEGMENTS > \sr
+	mtsr	\sr, \reg1
+	.endif
+.endm
+
+/*
+ * This isync() shouldn't be necessary as the kernel is not excepted to run
+ * any instruction in userspace soon after the update of segments and 'rfi'
+ * instruction is used to return to userspace, but hash based cores
+ * (at least G3) seem to exhibit a random behaviour when the 'isync' is not
+ * there. 603 cores don't have this behaviour so don't do the 'isync' as it
+ * saves several CPU cycles.
+ */
+.macro uus_isync
+#ifdef CONFIG_PPC_BOOK3S_604
+BEGIN_MMU_FTR_SECTION
+	isync
+END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE)
+#endif
+.endm
+
+.macro update_user_segments_by_4 tmp1 tmp2 tmp3 tmp4
+	uus_addi	1, \tmp2, \tmp1, 0x111
+	uus_addi	2, \tmp3, \tmp1, 0x222
+	uus_addi	3, \tmp4, \tmp1, 0x333
+
+	uus_mtsr	0, \tmp1
+	uus_mtsr	1, \tmp2
+	uus_mtsr	2, \tmp3
+	uus_mtsr	3, \tmp4
+
+	uus_addi	4, \tmp1, \tmp1, 0x444
+	uus_addi	5, \tmp2, \tmp2, 0x444
+	uus_addi	6, \tmp3, \tmp3, 0x444
+	uus_addi	7, \tmp4, \tmp4, 0x444
+
+	uus_mtsr	4, \tmp1
+	uus_mtsr	5, \tmp2
+	uus_mtsr	6, \tmp3
+	uus_mtsr	7, \tmp4
+
+	uus_addi	8, \tmp1, \tmp1, 0x444
+	uus_addi	9, \tmp2, \tmp2, 0x444
+	uus_addi	10, \tmp3, \tmp3, 0x444
+	uus_addi	11, \tmp4, \tmp4, 0x444
+
+	uus_mtsr	8, \tmp1
+	uus_mtsr	9, \tmp2
+	uus_mtsr	10, \tmp3
+	uus_mtsr	11, \tmp4
+
+	uus_addi	12, \tmp1, \tmp1, 0x444
+	uus_addi	13, \tmp2, \tmp2, 0x444
+	uus_addi	14, \tmp3, \tmp3, 0x444
+	uus_addi	15, \tmp4, \tmp4, 0x444
+
+	uus_mtsr	12, \tmp1
+	uus_mtsr	13, \tmp2
+	uus_mtsr	14, \tmp3
+	uus_mtsr	15, \tmp4
+
+	uus_isync
+.endm
+
+#else
 
 /*
  * This macro defines the mapping from contexts to VSIDs (virtual
diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index 6b800d3e2681..03afc4e7928e 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -139,12 +139,10 @@ static inline void interrupt_enter_prepare(struct pt_regs *regs, struct interrup
 	if (!arch_irq_disabled_regs(regs))
 		trace_hardirqs_off();
 
-	if (user_mode(regs)) {
-		kuep_lock();
+	if (user_mode(regs))
 		account_cpu_user_entry();
-	} else {
+	else
 		kuap_save_and_lock(regs);
-	}
 #endif
 
 #ifdef CONFIG_PPC64
diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index 1df763002726..34ff86e3686e 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -38,11 +38,6 @@ void setup_kuep(bool disabled);
 static inline void setup_kuep(bool disabled) { }
 #endif /* CONFIG_PPC_KUEP */
 
-#ifndef CONFIG_PPC_BOOK3S_32
-static inline void kuep_lock(void) { }
-static inline void kuep_unlock(void) { }
-#endif
-
 #ifdef CONFIG_PPC_KUAP
 void setup_kuap(bool disabled);
 #else
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 61fdd53cdd9a..4ba6a8c43475 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -73,6 +73,34 @@ prepare_transfer_to_handler:
 _ASM_NOKPROBE_SYMBOL(prepare_transfer_to_handler)
 #endif /* CONFIG_PPC_BOOK3S_32 || CONFIG_E500 */
 
+#if defined(CONFIG_PPC_KUEP) && defined(CONFIG_PPC_BOOK3S_32)
+	.globl	__kuep_lock
+__kuep_lock:
+	mfsr    r9,0
+	rlwinm  r9,r9,0,8,3
+	oris    r9,r9,SR_NX@h
+	update_user_segments_by_4 r9, r10, r11, r12
+	blr
+
+__kuep_unlock:
+	mfsr    r9,0
+	rlwinm  r9,r9,0,8,2
+	update_user_segments_by_4 r9, r10, r11, r12
+	blr
+
+.macro	kuep_lock
+	bl	__kuep_lock
+.endm
+.macro	kuep_unlock
+	bl	__kuep_unlock
+.endm
+#else
+.macro	kuep_lock
+.endm
+.macro	kuep_unlock
+.endm
+#endif
+
 	.globl	transfer_to_syscall
 transfer_to_syscall:
 	stw	r11, GPR1(r1)
@@ -94,6 +122,7 @@ transfer_to_syscall:
 	SAVE_2GPRS(7, r1)
 	addi	r2,r10,-THREAD
 	SAVE_NVGPRS(r1)
+	kuep_lock
 
 	/* Calling convention has r9 = orig r0, r10 = regs */
 	addi	r10,r1,STACK_FRAME_OVERHEAD
@@ -110,6 +139,7 @@ ret_from_syscall:
 	cmplwi	cr0,r5,0
 	bne-	2f
 #endif /* CONFIG_PPC_47x */
+	kuep_unlock
 	lwz	r4,_LINK(r1)
 	lwz	r5,_CCR(r1)
 	mtlr	r4
@@ -273,6 +303,7 @@ interrupt_return:
 	beq	.Lkernel_interrupt_return
 	bl	interrupt_exit_user_prepare
 	cmpwi	r3,0
+	kuep_unlock
 	bne-	.Lrestore_nvgprs
 
 .Lfast_user_interrupt_return:
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 6b1ec9e3541b..133197039775 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -136,6 +136,12 @@ _ASM_NOKPROBE_SYMBOL(\name\()_virt)
 	andi.	r12,r9,MSR_PR
 	bne	777f
 	bl	prepare_transfer_to_handler
+#ifdef CONFIG_PPC_KUEP
+	b	778f
+777:
+	bl	__kuep_lock
+778:
+#endif
 777:
 #endif
 .endm
diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
index de10a2697258..0d12aa66e1f9 100644
--- a/arch/powerpc/kernel/interrupt.c
+++ b/arch/powerpc/kernel/interrupt.c
@@ -81,8 +81,6 @@ notrace long system_call_exception(long r3, long r4, long r5,
 {
 	syscall_fn f;
 
-	kuep_lock();
-
 	regs->orig_gpr3 = r3;
 
 	if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
@@ -406,7 +404,6 @@ interrupt_exit_user_prepare_main(unsigned long ret, struct pt_regs *regs)
 
 	/* Restore user access locks last */
 	kuap_user_restore(regs);
-	kuep_unlock();
 
 	return ret;
 }
diff --git a/arch/powerpc/mm/book3s32/kuep.c b/arch/powerpc/mm/book3s32/kuep.c
index c20733d6e02c..45c9967f9aef 100644
--- a/arch/powerpc/mm/book3s32/kuep.c
+++ b/arch/powerpc/mm/book3s32/kuep.c
@@ -7,8 +7,13 @@ struct static_key_false disable_kuep_key;
 
 void setup_kuep(bool disabled)
 {
+	if (disabled) {
+		pr_info("KUEP cannot be disabled for the time being\n");
+		disabled = false;
+	}
+
 	if (!disabled)
-		kuep_lock();
+		update_user_segments(mfsr(0) | SR_NX);
 
 	if (smp_processor_id() != boot_cpuid)
 		return;
-- 
2.31.1

[PATCH v1 01/15] powerpc/32s: Do kuep_lock() and kuep_unlock() in assembly

[Christophe Leroy]

When interrupt and syscall entries where converted to C, KUEP locking
and unlocking was also converted. It improved performance by unrolling
the loop, and allowed easily implementing boot time deactivation of
KUEP.

However, null_syscall selftest shows that KUEP is still heavy
(361 cycles with KUEP, 212 cycles without).

A way to improve more is to group 'mtsr's together, instead of
repeating 'addi' + 'mtsr' several times.

In order to do that, more registers need to be available. In C, GCC
will always be able to provide the requested number of registers, but
at the cost of saving some data on the stack, which is counter
performant here.

So let's do it in assembly, when we have full control of which
register can be used. It also has the advantage of locking earlier
and unlocking later and it helps GCC generating less tricky code.
The only drawback is to make boot time deactivation less straight
forward and require 'hand' instruction patching.

Group 'mtsr's by 4.

With this change, null_syscall selftest reports 336 cycles. Without
the change it was 361 cycles, that's a 7% reduction.

For the time being, capability to deactivate at boot time is disabled.
It will be re-enabled in following patch.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/book3s/32/kup.h      | 34 --------
 arch/powerpc/include/asm/book3s/32/mmu-hash.h | 77 ++++++++++++++++++-
 arch/powerpc/include/asm/interrupt.h          |  6 +-
 arch/powerpc/include/asm/kup.h                |  5 --
 arch/powerpc/kernel/entry_32.S                | 31 ++++++++
 arch/powerpc/kernel/head_32.h                 |  6 ++
 arch/powerpc/kernel/interrupt.c               |  3 -
 arch/powerpc/mm/book3s32/kuep.c               |  7 +-
 8 files changed, 121 insertions(+), 48 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h
index d4b145b279f6..f159efd04ebc 100644
--- a/arch/powerpc/include/asm/book3s/32/kup.h
+++ b/arch/powerpc/include/asm/book3s/32/kup.h
@@ -24,40 +24,6 @@ static __always_inline bool kuep_is_disabled(void)
 	return !IS_ENABLED(CONFIG_PPC_KUEP) || static_branch_unlikely(&disable_kuep_key);
 }
 
-static inline void kuep_lock(void)
-{
-	if (kuep_is_disabled())
-		return;
-
-	update_user_segments(mfsr(0) | SR_NX);
-	/*
-	 * This isync() shouldn't be necessary as the kernel is not excepted to
-	 * run any instruction in userspace soon after the update of segments,
-	 * but hash based cores (at least G3) seem to exhibit a random
-	 * behaviour when the 'isync' is not there. 603 cores don't have this
-	 * behaviour so don't do the 'isync' as it saves several CPU cycles.
-	 */
-	if (mmu_has_feature(MMU_FTR_HPTE_TABLE))
-		isync();	/* Context sync required after mtsr() */
-}
-
-static inline void kuep_unlock(void)
-{
-	if (kuep_is_disabled())
-		return;
-
-	update_user_segments(mfsr(0) & ~SR_NX);
-	/*
-	 * This isync() shouldn't be necessary as a 'rfi' will soon be executed
-	 * to return to userspace, but hash based cores (at least G3) seem to
-	 * exhibit a random behaviour when the 'isync' is not there. 603 cores
-	 * don't have this behaviour so don't do the 'isync' as it saves several
-	 * CPU cycles.
-	 */
-	if (mmu_has_feature(MMU_FTR_HPTE_TABLE))
-		isync();	/* Context sync required after mtsr() */
-}
-
 #ifdef CONFIG_PPC_KUAP
 
 #include <linux/sched.h>
diff --git a/arch/powerpc/include/asm/book3s/32/mmu-hash.h b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
index f5be185cbdf8..e2f7ccc13edb 100644
--- a/arch/powerpc/include/asm/book3s/32/mmu-hash.h
+++ b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
@@ -64,7 +64,82 @@ struct ppc_bat {
 #define SR_KP	0x20000000	/* User key */
 #define SR_KS	0x40000000	/* Supervisor key */
 
-#ifndef __ASSEMBLY__
+#ifdef __ASSEMBLY__
+
+#include <asm/asm-offsets.h>
+
+.macro uus_addi sr reg1 reg2 imm
+	.if NUM_USER_SEGMENTS > \sr
+	addi	\reg1,\reg2,\imm
+	.endif
+.endm
+
+.macro uus_mtsr sr reg1
+	.if NUM_USER_SEGMENTS > \sr
+	mtsr	\sr, \reg1
+	.endif
+.endm
+
+/*
+ * This isync() shouldn't be necessary as the kernel is not excepted to run
+ * any instruction in userspace soon after the update of segments and 'rfi'
+ * instruction is used to return to userspace, but hash based cores
+ * (at least G3) seem to exhibit a random behaviour when the 'isync' is not
+ * there. 603 cores don't have this behaviour so don't do the 'isync' as it
+ * saves several CPU cycles.
+ */
+.macro uus_isync
+#ifdef CONFIG_PPC_BOOK3S_604
+BEGIN_MMU_FTR_SECTION
+	isync
+END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE)
+#endif
+.endm
+
+.macro update_user_segments_by_4 tmp1 tmp2 tmp3 tmp4
+	uus_addi	1, \tmp2, \tmp1, 0x111
+	uus_addi	2, \tmp3, \tmp1, 0x222
+	uus_addi	3, \tmp4, \tmp1, 0x333
+
+	uus_mtsr	0, \tmp1
+	uus_mtsr	1, \tmp2
+	uus_mtsr	2, \tmp3
+	uus_mtsr	3, \tmp4
+
+	uus_addi	4, \tmp1, \tmp1, 0x444
+	uus_addi	5, \tmp2, \tmp2, 0x444
+	uus_addi	6, \tmp3, \tmp3, 0x444
+	uus_addi	7, \tmp4, \tmp4, 0x444
+
+	uus_mtsr	4, \tmp1
+	uus_mtsr	5, \tmp2
+	uus_mtsr	6, \tmp3
+	uus_mtsr	7, \tmp4
+
+	uus_addi	8, \tmp1, \tmp1, 0x444
+	uus_addi	9, \tmp2, \tmp2, 0x444
+	uus_addi	10, \tmp3, \tmp3, 0x444
+	uus_addi	11, \tmp4, \tmp4, 0x444
+
+	uus_mtsr	8, \tmp1
+	uus_mtsr	9, \tmp2
+	uus_mtsr	10, \tmp3
+	uus_mtsr	11, \tmp4
+
+	uus_addi	12, \tmp1, \tmp1, 0x444
+	uus_addi	13, \tmp2, \tmp2, 0x444
+	uus_addi	14, \tmp3, \tmp3, 0x444
+	uus_addi	15, \tmp4, \tmp4, 0x444
+
+	uus_mtsr	12, \tmp1
+	uus_mtsr	13, \tmp2
+	uus_mtsr	14, \tmp3
+	uus_mtsr	15, \tmp4
+
+	uus_isync
+.endm
+
+#else
 
 /*
  * This macro defines the mapping from contexts to VSIDs (virtual
diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index 6b800d3e2681..03afc4e7928e 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -139,12 +139,10 @@ static inline void interrupt_enter_prepare(struct pt_regs *regs, struct interrup
 	if (!arch_irq_disabled_regs(regs))
 		trace_hardirqs_off();
 
-	if (user_mode(regs)) {
-		kuep_lock();
+	if (user_mode(regs))
 		account_cpu_user_entry();
-	} else {
+	else
 		kuap_save_and_lock(regs);
-	}
 #endif
 
 #ifdef CONFIG_PPC64
diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index 1df763002726..34ff86e3686e 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -38,11 +38,6 @@ void setup_kuep(bool disabled);
 static inline void setup_kuep(bool disabled) { }
 #endif /* CONFIG_PPC_KUEP */
 
-#ifndef CONFIG_PPC_BOOK3S_32
-static inline void kuep_lock(void) { }
-static inline void kuep_unlock(void) { }
-#endif
-
 #ifdef CONFIG_PPC_KUAP
 void setup_kuap(bool disabled);
 #else
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 61fdd53cdd9a..4ba6a8c43475 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -73,6 +73,34 @@ prepare_transfer_to_handler:
 _ASM_NOKPROBE_SYMBOL(prepare_transfer_to_handler)
 #endif /* CONFIG_PPC_BOOK3S_32 || CONFIG_E500 */
 
+#if defined(CONFIG_PPC_KUEP) && defined(CONFIG_PPC_BOOK3S_32)
+	.globl	__kuep_lock
+__kuep_lock:
+	mfsr    r9,0
+	rlwinm  r9,r9,0,8,3
+	oris    r9,r9,SR_NX@h
+	update_user_segments_by_4 r9, r10, r11, r12
+	blr
+
+__kuep_unlock:
+	mfsr    r9,0
+	rlwinm  r9,r9,0,8,2
+	update_user_segments_by_4 r9, r10, r11, r12
+	blr
+
+.macro	kuep_lock
+	bl	__kuep_lock
+.endm
+.macro	kuep_unlock
+	bl	__kuep_unlock
+.endm
+#else
+.macro	kuep_lock
+.endm
+.macro	kuep_unlock
+.endm
+#endif
+
 	.globl	transfer_to_syscall
 transfer_to_syscall:
 	stw	r11, GPR1(r1)
@@ -94,6 +122,7 @@ transfer_to_syscall:
 	SAVE_2GPRS(7, r1)
 	addi	r2,r10,-THREAD
 	SAVE_NVGPRS(r1)
+	kuep_lock
 
 	/* Calling convention has r9 = orig r0, r10 = regs */
 	addi	r10,r1,STACK_FRAME_OVERHEAD
@@ -110,6 +139,7 @@ ret_from_syscall:
 	cmplwi	cr0,r5,0
 	bne-	2f
 #endif /* CONFIG_PPC_47x */
+	kuep_unlock
 	lwz	r4,_LINK(r1)
 	lwz	r5,_CCR(r1)
 	mtlr	r4
@@ -273,6 +303,7 @@ interrupt_return:
 	beq	.Lkernel_interrupt_return
 	bl	interrupt_exit_user_prepare
 	cmpwi	r3,0
+	kuep_unlock
 	bne-	.Lrestore_nvgprs
 
 .Lfast_user_interrupt_return:
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 6b1ec9e3541b..133197039775 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -136,6 +136,12 @@ _ASM_NOKPROBE_SYMBOL(\name\()_virt)
 	andi.	r12,r9,MSR_PR
 	bne	777f
 	bl	prepare_transfer_to_handler
+#ifdef CONFIG_PPC_KUEP
+	b	778f
+777:
+	bl	__kuep_lock
+778:
+#endif
 777:
 #endif
 .endm
diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
index de10a2697258..0d12aa66e1f9 100644
--- a/arch/powerpc/kernel/interrupt.c
+++ b/arch/powerpc/kernel/interrupt.c
@@ -81,8 +81,6 @@ notrace long system_call_exception(long r3, long r4, long r5,
 {
 	syscall_fn f;
 
-	kuep_lock();
-
 	regs->orig_gpr3 = r3;
 
 	if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
@@ -406,7 +404,6 @@ interrupt_exit_user_prepare_main(unsigned long ret, struct pt_regs *regs)
 
 	/* Restore user access locks last */
 	kuap_user_restore(regs);
-	kuep_unlock();
 
 	return ret;
 }
diff --git a/arch/powerpc/mm/book3s32/kuep.c b/arch/powerpc/mm/book3s32/kuep.c
index c20733d6e02c..45c9967f9aef 100644
--- a/arch/powerpc/mm/book3s32/kuep.c
+++ b/arch/powerpc/mm/book3s32/kuep.c
@@ -7,8 +7,13 @@ struct static_key_false disable_kuep_key;
 
 void setup_kuep(bool disabled)
 {
+	if (disabled) {
+		pr_info("KUEP cannot be disabled for the time being\n");
+		disabled = false;
+	}
+
 	if (!disabled)
-		kuep_lock();
+		update_user_segments(mfsr(0) | SR_NX);
 
 	if (smp_processor_id() != boot_cpuid)
 		return;
-- 
2.31.1

[PATCH v1 02/15] powerpc/32s: Save content of sr0 to avoid 'mfsr'

[Christophe Leroy]

Calling 'mfsr' to get the content of segment registers is heavy,
in addition it requires clearing of the 'reserved' bits.

In order to avoid this operation, save it in mm context and in
thread struct.

The saved sr0 is the one used by kernel, this means that on
locking entry it can be used as is.

For unlocking, the only thing to do is to clear SR_NX.

This improves null_syscall selftest by 12 cycles, ie 4%.

Capability to deactivate KUEP at boot time is re-enabled by this patch.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
v3: Simplified patching implied by simplified preceding patch
---
 arch/powerpc/include/asm/book3s/32/kup.h      |  2 ++
 arch/powerpc/include/asm/book3s/32/mmu-hash.h |  1 +
 arch/powerpc/include/asm/processor.h          |  1 +
 arch/powerpc/kernel/entry_32.S                | 11 +++++----
 arch/powerpc/mm/book3s32/kuap.c               |  5 +++-
 arch/powerpc/mm/book3s32/kuep.c               | 24 ++++++++++++-------
 arch/powerpc/mm/book3s32/mmu_context.c        | 15 ++++++------
 arch/powerpc/mm/mmu_context.c                 |  3 +++
 8 files changed, 40 insertions(+), 22 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h
index f159efd04ebc..f03fe357471f 100644
--- a/arch/powerpc/include/asm/book3s/32/kup.h
+++ b/arch/powerpc/include/asm/book3s/32/kup.h
@@ -14,6 +14,8 @@
 extern struct static_key_false disable_kuap_key;
 extern struct static_key_false disable_kuep_key;
 
+extern s32 patch__kuep_lock, patch__kuep_unlock;
+
 static __always_inline bool kuap_is_disabled(void)
 {
 	return !IS_ENABLED(CONFIG_PPC_KUAP) || static_branch_unlikely(&disable_kuap_key);
diff --git a/arch/powerpc/include/asm/book3s/32/mmu-hash.h b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
index e2f7ccc13edb..ecc148c1e795 100644
--- a/arch/powerpc/include/asm/book3s/32/mmu-hash.h
+++ b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
@@ -175,6 +175,7 @@ struct hash_pte {
 
 typedef struct {
 	unsigned long id;
+	unsigned long sr0;
 	void __user *vdso;
 } mm_context_t;
 
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index f348e564f7dd..4b13f94a4f42 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -157,6 +157,7 @@ struct thread_struct {
 #ifdef CONFIG_PPC_BOOK3S_32
 	unsigned long	r0, r3, r4, r5, r6, r8, r9, r11;
 	unsigned long	lr, ctr;
+	unsigned long	sr0;
 #endif
 #endif /* CONFIG_PPC32 */
 	/* Debug Registers */
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 4ba6a8c43475..9d31ba2af901 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -33,6 +33,7 @@
 #include <asm/kup.h>
 #include <asm/bug.h>
 #include <asm/interrupt.h>
+#include <asm/code-patching-asm.h>
 
 #include "head_32.h"
 
@@ -76,17 +77,17 @@ _ASM_NOKPROBE_SYMBOL(prepare_transfer_to_handler)
 #if defined(CONFIG_PPC_KUEP) && defined(CONFIG_PPC_BOOK3S_32)
 	.globl	__kuep_lock
 __kuep_lock:
-	mfsr    r9,0
-	rlwinm  r9,r9,0,8,3
-	oris    r9,r9,SR_NX@h
+0:	blr	/* lwz	r9, current->thread.sr0(r2) */
 	update_user_segments_by_4 r9, r10, r11, r12
 	blr
+	patch_site	0b, patch__kuep_lock
 
 __kuep_unlock:
-	mfsr    r9,0
-	rlwinm  r9,r9,0,8,2
+0:	blr	/* lwz	r9, current->thread.sr0(r2) */
+	rlwinm  r9,r9,0,~SR_NX
 	update_user_segments_by_4 r9, r10, r11, r12
 	blr
+	patch_site	0b, patch__kuep_unlock
 
 .macro	kuep_lock
 	bl	__kuep_lock
diff --git a/arch/powerpc/mm/book3s32/kuap.c b/arch/powerpc/mm/book3s32/kuap.c
index 0f920f09af57..28676cabb005 100644
--- a/arch/powerpc/mm/book3s32/kuap.c
+++ b/arch/powerpc/mm/book3s32/kuap.c
@@ -20,8 +20,11 @@ EXPORT_SYMBOL(kuap_unlock_all_ool);
 
 void setup_kuap(bool disabled)
 {
-	if (!disabled)
+	if (!disabled) {
 		kuap_lock_all_ool();
+		init_mm.context.sr0 |= SR_KS;
+		current->thread.sr0 |= SR_KS;
+	}
 
 	if (smp_processor_id() != boot_cpuid)
 		return;
diff --git a/arch/powerpc/mm/book3s32/kuep.c b/arch/powerpc/mm/book3s32/kuep.c
index 45c9967f9aef..0be25492b42d 100644
--- a/arch/powerpc/mm/book3s32/kuep.c
+++ b/arch/powerpc/mm/book3s32/kuep.c
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
+#include <asm/code-patching.h>
 #include <asm/kup.h>
 #include <asm/smp.h>
 
@@ -7,19 +8,26 @@ struct static_key_false disable_kuep_key;
 
 void setup_kuep(bool disabled)
 {
-	if (disabled) {
-		pr_info("KUEP cannot be disabled for the time being\n");
-		disabled = false;
-	}
+	u32 insn;
 
-	if (!disabled)
-		update_user_segments(mfsr(0) | SR_NX);
+	if (!disabled) {
+		init_mm.context.sr0 |= SR_NX;
+		current->thread.sr0 |= SR_NX;
+		update_user_segments(init_mm.context.sr0);
+	}
 
 	if (smp_processor_id() != boot_cpuid)
 		return;
 
 	if (disabled)
 		static_branch_enable(&disable_kuep_key);
-	else
-		pr_info("Activating Kernel Userspace Execution Prevention\n");
+
+	if (disabled)
+		return;
+
+	insn = PPC_RAW_LWZ(_R9, _R2, offsetof(struct task_struct, thread.sr0));
+	patch_instruction_site(&patch__kuep_lock, ppc_inst(insn));
+	patch_instruction_site(&patch__kuep_unlock, ppc_inst(insn));
+
+	pr_info("Activating Kernel Userspace Execution Prevention\n");
 }
diff --git a/arch/powerpc/mm/book3s32/mmu_context.c b/arch/powerpc/mm/book3s32/mmu_context.c
index e2708e387dc3..269a3eb25a73 100644
--- a/arch/powerpc/mm/book3s32/mmu_context.c
+++ b/arch/powerpc/mm/book3s32/mmu_context.c
@@ -69,6 +69,12 @@ EXPORT_SYMBOL_GPL(__init_new_context);
 int init_new_context(struct task_struct *t, struct mm_struct *mm)
 {
 	mm->context.id = __init_new_context();
+	mm->context.sr0 = CTX_TO_VSID(mm->context.id, 0);
+
+	if (!kuep_is_disabled())
+		mm->context.sr0 |= SR_NX;
+	if (!kuap_is_disabled())
+		mm->context.sr0 |= SR_KS;
 
 	return 0;
 }
@@ -108,20 +114,13 @@ void __init mmu_context_init(void)
 void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk)
 {
 	long id = next->context.id;
-	unsigned long val;
 
 	if (id < 0)
 		panic("mm_struct %p has no context ID", next);
 
 	isync();
 
-	val = CTX_TO_VSID(id, 0);
-	if (!kuep_is_disabled())
-		val |= SR_NX;
-	if (!kuap_is_disabled())
-		val |= SR_KS;
-
-	update_user_segments(val);
+	update_user_segments(next->context.sr0);
 
 	if (IS_ENABLED(CONFIG_BDI_SWITCH))
 		abatron_pteptrs[1] = next->pgd;
diff --git a/arch/powerpc/mm/mmu_context.c b/arch/powerpc/mm/mmu_context.c
index 74246536b832..e618d5442a28 100644
--- a/arch/powerpc/mm/mmu_context.c
+++ b/arch/powerpc/mm/mmu_context.c
@@ -18,6 +18,9 @@ static inline void switch_mm_pgdir(struct task_struct *tsk,
 {
 	/* 32-bit keeps track of the current PGDIR in the thread struct */
 	tsk->thread.pgdir = mm->pgd;
+#ifdef CONFIG_PPC_BOOK3S_32
+	tsk->thread.sr0 = mm->context.sr0;
+#endif
 }
 #elif defined(CONFIG_PPC_BOOK3E_64)
 static inline void switch_mm_pgdir(struct task_struct *tsk,
-- 
2.31.1

[PATCH v1 02/15] powerpc/32s: Save content of sr0 to avoid 'mfsr'

[Christophe Leroy]

Calling 'mfsr' to get the content of segment registers is heavy,
in addition it requires clearing of the 'reserved' bits.

In order to avoid this operation, save it in mm context and in
thread struct.

The saved sr0 is the one used by kernel, this means that on
locking entry it can be used as is.

For unlocking, the only thing to do is to clear SR_NX.

This improves null_syscall selftest by 12 cycles, ie 4%.

Capability to deactivate KUEP at boot time is re-enabled by this patch.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
v3: Simplified patching implied by simplified preceding patch
---
 arch/powerpc/include/asm/book3s/32/kup.h      |  2 ++
 arch/powerpc/include/asm/book3s/32/mmu-hash.h |  1 +
 arch/powerpc/include/asm/processor.h          |  1 +
 arch/powerpc/kernel/entry_32.S                | 11 +++++----
 arch/powerpc/mm/book3s32/kuap.c               |  5 +++-
 arch/powerpc/mm/book3s32/kuep.c               | 24 ++++++++++++-------
 arch/powerpc/mm/book3s32/mmu_context.c        | 15 ++++++------
 arch/powerpc/mm/mmu_context.c                 |  3 +++
 8 files changed, 40 insertions(+), 22 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h
index f159efd04ebc..f03fe357471f 100644
--- a/arch/powerpc/include/asm/book3s/32/kup.h
+++ b/arch/powerpc/include/asm/book3s/32/kup.h
@@ -14,6 +14,8 @@
 extern struct static_key_false disable_kuap_key;
 extern struct static_key_false disable_kuep_key;
 
+extern s32 patch__kuep_lock, patch__kuep_unlock;
+
 static __always_inline bool kuap_is_disabled(void)
 {
 	return !IS_ENABLED(CONFIG_PPC_KUAP) || static_branch_unlikely(&disable_kuap_key);
diff --git a/arch/powerpc/include/asm/book3s/32/mmu-hash.h b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
index e2f7ccc13edb..ecc148c1e795 100644
--- a/arch/powerpc/include/asm/book3s/32/mmu-hash.h
+++ b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
@@ -175,6 +175,7 @@ struct hash_pte {
 
 typedef struct {
 	unsigned long id;
+	unsigned long sr0;
 	void __user *vdso;
 } mm_context_t;
 
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index f348e564f7dd..4b13f94a4f42 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -157,6 +157,7 @@ struct thread_struct {
 #ifdef CONFIG_PPC_BOOK3S_32
 	unsigned long	r0, r3, r4, r5, r6, r8, r9, r11;
 	unsigned long	lr, ctr;
+	unsigned long	sr0;
 #endif
 #endif /* CONFIG_PPC32 */
 	/* Debug Registers */
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 4ba6a8c43475..9d31ba2af901 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -33,6 +33,7 @@
 #include <asm/kup.h>
 #include <asm/bug.h>
 #include <asm/interrupt.h>
+#include <asm/code-patching-asm.h>
 
 #include "head_32.h"
 
@@ -76,17 +77,17 @@ _ASM_NOKPROBE_SYMBOL(prepare_transfer_to_handler)
 #if defined(CONFIG_PPC_KUEP) && defined(CONFIG_PPC_BOOK3S_32)
 	.globl	__kuep_lock
 __kuep_lock:
-	mfsr    r9,0
-	rlwinm  r9,r9,0,8,3
-	oris    r9,r9,SR_NX@h
+0:	blr	/* lwz	r9, current->thread.sr0(r2) */
 	update_user_segments_by_4 r9, r10, r11, r12
 	blr
+	patch_site	0b, patch__kuep_lock
 
 __kuep_unlock:
-	mfsr    r9,0
-	rlwinm  r9,r9,0,8,2
+0:	blr	/* lwz	r9, current->thread.sr0(r2) */
+	rlwinm  r9,r9,0,~SR_NX
 	update_user_segments_by_4 r9, r10, r11, r12
 	blr
+	patch_site	0b, patch__kuep_unlock
 
 .macro	kuep_lock
 	bl	__kuep_lock
diff --git a/arch/powerpc/mm/book3s32/kuap.c b/arch/powerpc/mm/book3s32/kuap.c
index 0f920f09af57..28676cabb005 100644
--- a/arch/powerpc/mm/book3s32/kuap.c
+++ b/arch/powerpc/mm/book3s32/kuap.c
@@ -20,8 +20,11 @@ EXPORT_SYMBOL(kuap_unlock_all_ool);
 
 void setup_kuap(bool disabled)
 {
-	if (!disabled)
+	if (!disabled) {
 		kuap_lock_all_ool();
+		init_mm.context.sr0 |= SR_KS;
+		current->thread.sr0 |= SR_KS;
+	}
 
 	if (smp_processor_id() != boot_cpuid)
 		return;
diff --git a/arch/powerpc/mm/book3s32/kuep.c b/arch/powerpc/mm/book3s32/kuep.c
index 45c9967f9aef..0be25492b42d 100644
--- a/arch/powerpc/mm/book3s32/kuep.c
+++ b/arch/powerpc/mm/book3s32/kuep.c
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
+#include <asm/code-patching.h>
 #include <asm/kup.h>
 #include <asm/smp.h>
 
@@ -7,19 +8,26 @@ struct static_key_false disable_kuep_key;
 
 void setup_kuep(bool disabled)
 {
-	if (disabled) {
-		pr_info("KUEP cannot be disabled for the time being\n");
-		disabled = false;
-	}
+	u32 insn;
 
-	if (!disabled)
-		update_user_segments(mfsr(0) | SR_NX);
+	if (!disabled) {
+		init_mm.context.sr0 |= SR_NX;
+		current->thread.sr0 |= SR_NX;
+		update_user_segments(init_mm.context.sr0);
+	}
 
 	if (smp_processor_id() != boot_cpuid)
 		return;
 
 	if (disabled)
 		static_branch_enable(&disable_kuep_key);
-	else
-		pr_info("Activating Kernel Userspace Execution Prevention\n");
+
+	if (disabled)
+		return;
+
+	insn = PPC_RAW_LWZ(_R9, _R2, offsetof(struct task_struct, thread.sr0));
+	patch_instruction_site(&patch__kuep_lock, ppc_inst(insn));
+	patch_instruction_site(&patch__kuep_unlock, ppc_inst(insn));
+
+	pr_info("Activating Kernel Userspace Execution Prevention\n");
 }
diff --git a/arch/powerpc/mm/book3s32/mmu_context.c b/arch/powerpc/mm/book3s32/mmu_context.c
index e2708e387dc3..269a3eb25a73 100644
--- a/arch/powerpc/mm/book3s32/mmu_context.c
+++ b/arch/powerpc/mm/book3s32/mmu_context.c
@@ -69,6 +69,12 @@ EXPORT_SYMBOL_GPL(__init_new_context);
 int init_new_context(struct task_struct *t, struct mm_struct *mm)
 {
 	mm->context.id = __init_new_context();
+	mm->context.sr0 = CTX_TO_VSID(mm->context.id, 0);
+
+	if (!kuep_is_disabled())
+		mm->context.sr0 |= SR_NX;
+	if (!kuap_is_disabled())
+		mm->context.sr0 |= SR_KS;
 
 	return 0;
 }
@@ -108,20 +114,13 @@ void __init mmu_context_init(void)
 void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk)
 {
 	long id = next->context.id;
-	unsigned long val;
 
 	if (id < 0)
 		panic("mm_struct %p has no context ID", next);
 
 	isync();
 
-	val = CTX_TO_VSID(id, 0);
-	if (!kuep_is_disabled())
-		val |= SR_NX;
-	if (!kuap_is_disabled())
-		val |= SR_KS;
-
-	update_user_segments(val);
+	update_user_segments(next->context.sr0);
 
 	if (IS_ENABLED(CONFIG_BDI_SWITCH))
 		abatron_pteptrs[1] = next->pgd;
diff --git a/arch/powerpc/mm/mmu_context.c b/arch/powerpc/mm/mmu_context.c
index 74246536b832..e618d5442a28 100644
--- a/arch/powerpc/mm/mmu_context.c
+++ b/arch/powerpc/mm/mmu_context.c
@@ -18,6 +18,9 @@ static inline void switch_mm_pgdir(struct task_struct *tsk,
 {
 	/* 32-bit keeps track of the current PGDIR in the thread struct */
 	tsk->thread.pgdir = mm->pgd;
+#ifdef CONFIG_PPC_BOOK3S_32
+	tsk->thread.sr0 = mm->context.sr0;
+#endif
 }
 #elif defined(CONFIG_PPC_BOOK3E_64)
 static inline void switch_mm_pgdir(struct task_struct *tsk,
-- 
2.31.1

[PATCH v1 03/15] powerpc/kuap: Add a generic intermediate layer

[Christophe Leroy]

Make the following functions generic to all platforms.
- bad_kuap_fault()
- kuap_assert_locked()
- kuap_save_and_lock() (PPC32 only)
- kuap_kernel_restore()
- kuap_get_and_assert_locked()

And for all platforms except book3s/64
- allow_user_access()
- prevent_user_access()
- prevent_user_access_return()
- restore_user_access()

Prepend __ in front of the name of platform specific ones.

For now the generic just calls the platform specific, but
next patch will move redundant parts of specific functions
into the generic one.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/book3s/32/kup.h     | 22 +++---
 arch/powerpc/include/asm/book3s/64/kup.h     | 10 ++-
 arch/powerpc/include/asm/kup.h               | 71 +++++++++++++++++---
 arch/powerpc/include/asm/nohash/32/kup-8xx.h | 20 +++---
 4 files changed, 86 insertions(+), 37 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h
index f03fe357471f..c49fbe0418be 100644
--- a/arch/powerpc/include/asm/book3s/32/kup.h
+++ b/arch/powerpc/include/asm/book3s/32/kup.h
@@ -80,7 +80,7 @@ static inline void kuap_unlock(unsigned long addr, bool ool)
 		kuap_unlock_all_ool();
 }
 
-static inline void kuap_save_and_lock(struct pt_regs *regs)
+static inline void __kuap_save_and_lock(struct pt_regs *regs)
 {
 	unsigned long kuap = current->thread.kuap;
 
@@ -99,7 +99,7 @@ static inline void kuap_user_restore(struct pt_regs *regs)
 {
 }
 
-static inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
+static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
 {
 	if (kuap_is_disabled())
 		return;
@@ -109,7 +109,7 @@ static inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
 	kuap_unlock(regs->kuap, false);
 }
 
-static inline unsigned long kuap_get_and_assert_locked(void)
+static inline unsigned long __kuap_get_and_assert_locked(void)
 {
 	unsigned long kuap = current->thread.kuap;
 
@@ -121,13 +121,13 @@ static inline unsigned long kuap_get_and_assert_locked(void)
 	return kuap;
 }
 
-static inline void kuap_assert_locked(void)
+static inline void __kuap_assert_locked(void)
 {
-	kuap_get_and_assert_locked();
+	__kuap_get_and_assert_locked();
 }
 
-static __always_inline void allow_user_access(void __user *to, const void __user *from,
-					      u32 size, unsigned long dir)
+static __always_inline void __allow_user_access(void __user *to, const void __user *from,
+						u32 size, unsigned long dir)
 {
 	if (kuap_is_disabled())
 		return;
@@ -141,7 +141,7 @@ static __always_inline void allow_user_access(void __user *to, const void __user
 	kuap_unlock_one((__force u32)to);
 }
 
-static __always_inline void prevent_user_access(unsigned long dir)
+static __always_inline void __prevent_user_access(unsigned long dir)
 {
 	u32 kuap = current->thread.kuap;
 
@@ -157,7 +157,7 @@ static __always_inline void prevent_user_access(unsigned long dir)
 	kuap_lock(kuap, true);
 }
 
-static inline unsigned long prevent_user_access_return(void)
+static inline unsigned long __prevent_user_access_return(void)
 {
 	unsigned long flags = current->thread.kuap;
 
@@ -172,7 +172,7 @@ static inline unsigned long prevent_user_access_return(void)
 	return flags;
 }
 
-static inline void restore_user_access(unsigned long flags)
+static inline void __restore_user_access(unsigned long flags)
 {
 	if (kuap_is_disabled())
 		return;
@@ -184,7 +184,7 @@ static inline void restore_user_access(unsigned long flags)
 }
 
 static inline bool
-bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
+__bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
 {
 	unsigned long kuap = regs->kuap;
 
diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index 170339969b7c..03d61c5205a4 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -268,8 +268,7 @@ static inline void kuap_user_restore(struct pt_regs *regs)
 	 */
 }
 
-static inline void kuap_kernel_restore(struct pt_regs *regs,
-					   unsigned long amr)
+static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long amr)
 {
 	if (mmu_has_feature(MMU_FTR_BOOK3S_KUAP)) {
 		if (unlikely(regs->amr != amr)) {
@@ -287,7 +286,7 @@ static inline void kuap_kernel_restore(struct pt_regs *regs,
 	 */
 }
 
-static inline unsigned long kuap_get_and_assert_locked(void)
+static inline unsigned long __kuap_get_and_assert_locked(void)
 {
 	if (mmu_has_feature(MMU_FTR_BOOK3S_KUAP)) {
 		unsigned long amr = mfspr(SPRN_AMR);
@@ -298,7 +297,7 @@ static inline unsigned long kuap_get_and_assert_locked(void)
 	return 0;
 }
 
-static inline void kuap_assert_locked(void)
+static inline void __kuap_assert_locked(void)
 {
 	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && mmu_has_feature(MMU_FTR_BOOK3S_KUAP))
 		WARN_ON_ONCE(mfspr(SPRN_AMR) != AMR_KUAP_BLOCKED);
@@ -339,8 +338,7 @@ static inline void set_kuap(unsigned long value)
 	isync();
 }
 
-static inline bool bad_kuap_fault(struct pt_regs *regs, unsigned long address,
-				  bool is_write)
+static inline bool __bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
 {
 	if (!mmu_has_feature(MMU_FTR_BOOK3S_KUAP))
 		return false;
diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index 34ff86e3686e..3dbd3f77b413 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -44,17 +44,17 @@ void setup_kuap(bool disabled);
 static inline void setup_kuap(bool disabled) { }
 
 static inline bool
-bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
+__bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
 {
 	return false;
 }
 
-static inline void kuap_assert_locked(void) { }
-static inline void kuap_save_and_lock(struct pt_regs *regs) { }
+static inline void __kuap_assert_locked(void) { }
+static inline void __kuap_save_and_lock(struct pt_regs *regs) { }
 static inline void kuap_user_restore(struct pt_regs *regs) { }
-static inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long amr) { }
+static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long amr) { }
 
-static inline unsigned long kuap_get_and_assert_locked(void)
+static inline unsigned long __kuap_get_and_assert_locked(void)
 {
 	return 0;
 }
@@ -65,14 +65,65 @@ static inline unsigned long kuap_get_and_assert_locked(void)
  * platforms.
  */
 #ifndef CONFIG_PPC_BOOK3S_64
-static inline void allow_user_access(void __user *to, const void __user *from,
-				     unsigned long size, unsigned long dir) { }
-static inline void prevent_user_access(unsigned long dir) { }
-static inline unsigned long prevent_user_access_return(void) { return 0UL; }
-static inline void restore_user_access(unsigned long flags) { }
+static inline void __allow_user_access(void __user *to, const void __user *from,
+				       unsigned long size, unsigned long dir) { }
+static inline void __prevent_user_access(unsigned long dir) { }
+static inline unsigned long __prevent_user_access_return(void) { return 0UL; }
+static inline void __restore_user_access(unsigned long flags) { }
 #endif /* CONFIG_PPC_BOOK3S_64 */
 #endif /* CONFIG_PPC_KUAP */
 
+static __always_inline bool
+bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
+{
+	return __bad_kuap_fault(regs, address, is_write);
+}
+
+static __always_inline void kuap_assert_locked(void)
+{
+	__kuap_assert_locked();
+}
+
+#ifdef CONFIG_PPC32
+static __always_inline void kuap_save_and_lock(struct pt_regs *regs)
+{
+	__kuap_save_and_lock(regs);
+}
+#endif
+
+static __always_inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long amr)
+{
+	__kuap_kernel_restore(regs, amr);
+}
+
+static __always_inline unsigned long kuap_get_and_assert_locked(void)
+{
+	return __kuap_get_and_assert_locked();
+}
+
+#ifndef CONFIG_PPC_BOOK3S_64
+static __always_inline void allow_user_access(void __user *to, const void __user *from,
+				     unsigned long size, unsigned long dir)
+{
+	__allow_user_access(to, from, size, dir);
+}
+
+static __always_inline void prevent_user_access(unsigned long dir)
+{
+	__prevent_user_access(dir);
+}
+
+static __always_inline unsigned long prevent_user_access_return(void)
+{
+	return __prevent_user_access_return();
+}
+
+static __always_inline void restore_user_access(unsigned long flags)
+{
+	__restore_user_access(flags);
+}
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
 static __always_inline void setup_kup(void)
 {
 	setup_kuep(disable_kuep);
diff --git a/arch/powerpc/include/asm/nohash/32/kup-8xx.h b/arch/powerpc/include/asm/nohash/32/kup-8xx.h
index 882a0bc7887a..a5db84164afd 100644
--- a/arch/powerpc/include/asm/nohash/32/kup-8xx.h
+++ b/arch/powerpc/include/asm/nohash/32/kup-8xx.h
@@ -20,7 +20,7 @@ static __always_inline bool kuap_is_disabled(void)
 	return static_branch_unlikely(&disable_kuap_key);
 }
 
-static inline void kuap_save_and_lock(struct pt_regs *regs)
+static inline void __kuap_save_and_lock(struct pt_regs *regs)
 {
 	if (kuap_is_disabled())
 		return;
@@ -33,7 +33,7 @@ static inline void kuap_user_restore(struct pt_regs *regs)
 {
 }
 
-static inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
+static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
 {
 	if (kuap_is_disabled())
 		return;
@@ -41,7 +41,7 @@ static inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
 	mtspr(SPRN_MD_AP, regs->kuap);
 }
 
-static inline unsigned long kuap_get_and_assert_locked(void)
+static inline unsigned long __kuap_get_and_assert_locked(void)
 {
 	unsigned long kuap;
 
@@ -56,14 +56,14 @@ static inline unsigned long kuap_get_and_assert_locked(void)
 	return kuap;
 }
 
-static inline void kuap_assert_locked(void)
+static inline void __kuap_assert_locked(void)
 {
 	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && !kuap_is_disabled())
 		kuap_get_and_assert_locked();
 }
 
-static inline void allow_user_access(void __user *to, const void __user *from,
-				     unsigned long size, unsigned long dir)
+static inline void __allow_user_access(void __user *to, const void __user *from,
+				       unsigned long size, unsigned long dir)
 {
 	if (kuap_is_disabled())
 		return;
@@ -71,7 +71,7 @@ static inline void allow_user_access(void __user *to, const void __user *from,
 	mtspr(SPRN_MD_AP, MD_APG_INIT);
 }
 
-static inline void prevent_user_access(unsigned long dir)
+static inline void __prevent_user_access(unsigned long dir)
 {
 	if (kuap_is_disabled())
 		return;
@@ -79,7 +79,7 @@ static inline void prevent_user_access(unsigned long dir)
 	mtspr(SPRN_MD_AP, MD_APG_KUAP);
 }
 
-static inline unsigned long prevent_user_access_return(void)
+static inline unsigned long __prevent_user_access_return(void)
 {
 	unsigned long flags;
 
@@ -93,7 +93,7 @@ static inline unsigned long prevent_user_access_return(void)
 	return flags;
 }
 
-static inline void restore_user_access(unsigned long flags)
+static inline void __restore_user_access(unsigned long flags)
 {
 	if (kuap_is_disabled())
 		return;
@@ -102,7 +102,7 @@ static inline void restore_user_access(unsigned long flags)
 }
 
 static inline bool
-bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
+__bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
 {
 	if (kuap_is_disabled())
 		return false;
-- 
2.31.1

[PATCH v1 03/15] powerpc/kuap: Add a generic intermediate layer

[Christophe Leroy]

Make the following functions generic to all platforms.
- bad_kuap_fault()
- kuap_assert_locked()
- kuap_save_and_lock() (PPC32 only)
- kuap_kernel_restore()
- kuap_get_and_assert_locked()

And for all platforms except book3s/64
- allow_user_access()
- prevent_user_access()
- prevent_user_access_return()
- restore_user_access()

Prepend __ in front of the name of platform specific ones.

For now the generic just calls the platform specific, but
next patch will move redundant parts of specific functions
into the generic one.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/book3s/32/kup.h     | 22 +++---
 arch/powerpc/include/asm/book3s/64/kup.h     | 10 ++-
 arch/powerpc/include/asm/kup.h               | 71 +++++++++++++++++---
 arch/powerpc/include/asm/nohash/32/kup-8xx.h | 20 +++---
 4 files changed, 86 insertions(+), 37 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h
index f03fe357471f..c49fbe0418be 100644
--- a/arch/powerpc/include/asm/book3s/32/kup.h
+++ b/arch/powerpc/include/asm/book3s/32/kup.h
@@ -80,7 +80,7 @@ static inline void kuap_unlock(unsigned long addr, bool ool)
 		kuap_unlock_all_ool();
 }
 
-static inline void kuap_save_and_lock(struct pt_regs *regs)
+static inline void __kuap_save_and_lock(struct pt_regs *regs)
 {
 	unsigned long kuap = current->thread.kuap;
 
@@ -99,7 +99,7 @@ static inline void kuap_user_restore(struct pt_regs *regs)
 {
 }
 
-static inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
+static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
 {
 	if (kuap_is_disabled())
 		return;
@@ -109,7 +109,7 @@ static inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
 	kuap_unlock(regs->kuap, false);
 }
 
-static inline unsigned long kuap_get_and_assert_locked(void)
+static inline unsigned long __kuap_get_and_assert_locked(void)
 {
 	unsigned long kuap = current->thread.kuap;
 
@@ -121,13 +121,13 @@ static inline unsigned long kuap_get_and_assert_locked(void)
 	return kuap;
 }
 
-static inline void kuap_assert_locked(void)
+static inline void __kuap_assert_locked(void)
 {
-	kuap_get_and_assert_locked();
+	__kuap_get_and_assert_locked();
 }
 
-static __always_inline void allow_user_access(void __user *to, const void __user *from,
-					      u32 size, unsigned long dir)
+static __always_inline void __allow_user_access(void __user *to, const void __user *from,
+						u32 size, unsigned long dir)
 {
 	if (kuap_is_disabled())
 		return;
@@ -141,7 +141,7 @@ static __always_inline void allow_user_access(void __user *to, const void __user
 	kuap_unlock_one((__force u32)to);
 }
 
-static __always_inline void prevent_user_access(unsigned long dir)
+static __always_inline void __prevent_user_access(unsigned long dir)
 {
 	u32 kuap = current->thread.kuap;
 
@@ -157,7 +157,7 @@ static __always_inline void prevent_user_access(unsigned long dir)
 	kuap_lock(kuap, true);
 }
 
-static inline unsigned long prevent_user_access_return(void)
+static inline unsigned long __prevent_user_access_return(void)
 {
 	unsigned long flags = current->thread.kuap;
 
@@ -172,7 +172,7 @@ static inline unsigned long prevent_user_access_return(void)
 	return flags;
 }
 
-static inline void restore_user_access(unsigned long flags)
+static inline void __restore_user_access(unsigned long flags)
 {
 	if (kuap_is_disabled())
 		return;
@@ -184,7 +184,7 @@ static inline void restore_user_access(unsigned long flags)
 }
 
 static inline bool
-bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
+__bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
 {
 	unsigned long kuap = regs->kuap;
 
diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index 170339969b7c..03d61c5205a4 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -268,8 +268,7 @@ static inline void kuap_user_restore(struct pt_regs *regs)
 	 */
 }
 
-static inline void kuap_kernel_restore(struct pt_regs *regs,
-					   unsigned long amr)
+static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long amr)
 {
 	if (mmu_has_feature(MMU_FTR_BOOK3S_KUAP)) {
 		if (unlikely(regs->amr != amr)) {
@@ -287,7 +286,7 @@ static inline void kuap_kernel_restore(struct pt_regs *regs,
 	 */
 }
 
-static inline unsigned long kuap_get_and_assert_locked(void)
+static inline unsigned long __kuap_get_and_assert_locked(void)
 {
 	if (mmu_has_feature(MMU_FTR_BOOK3S_KUAP)) {
 		unsigned long amr = mfspr(SPRN_AMR);
@@ -298,7 +297,7 @@ static inline unsigned long kuap_get_and_assert_locked(void)
 	return 0;
 }
 
-static inline void kuap_assert_locked(void)
+static inline void __kuap_assert_locked(void)
 {
 	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && mmu_has_feature(MMU_FTR_BOOK3S_KUAP))
 		WARN_ON_ONCE(mfspr(SPRN_AMR) != AMR_KUAP_BLOCKED);
@@ -339,8 +338,7 @@ static inline void set_kuap(unsigned long value)
 	isync();
 }
 
-static inline bool bad_kuap_fault(struct pt_regs *regs, unsigned long address,
-				  bool is_write)
+static inline bool __bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
 {
 	if (!mmu_has_feature(MMU_FTR_BOOK3S_KUAP))
 		return false;
diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index 34ff86e3686e..3dbd3f77b413 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -44,17 +44,17 @@ void setup_kuap(bool disabled);
 static inline void setup_kuap(bool disabled) { }
 
 static inline bool
-bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
+__bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
 {
 	return false;
 }
 
-static inline void kuap_assert_locked(void) { }
-static inline void kuap_save_and_lock(struct pt_regs *regs) { }
+static inline void __kuap_assert_locked(void) { }
+static inline void __kuap_save_and_lock(struct pt_regs *regs) { }
 static inline void kuap_user_restore(struct pt_regs *regs) { }
-static inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long amr) { }
+static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long amr) { }
 
-static inline unsigned long kuap_get_and_assert_locked(void)
+static inline unsigned long __kuap_get_and_assert_locked(void)
 {
 	return 0;
 }
@@ -65,14 +65,65 @@ static inline unsigned long kuap_get_and_assert_locked(void)
  * platforms.
  */
 #ifndef CONFIG_PPC_BOOK3S_64
-static inline void allow_user_access(void __user *to, const void __user *from,
-				     unsigned long size, unsigned long dir) { }
-static inline void prevent_user_access(unsigned long dir) { }
-static inline unsigned long prevent_user_access_return(void) { return 0UL; }
-static inline void restore_user_access(unsigned long flags) { }
+static inline void __allow_user_access(void __user *to, const void __user *from,
+				       unsigned long size, unsigned long dir) { }
+static inline void __prevent_user_access(unsigned long dir) { }
+static inline unsigned long __prevent_user_access_return(void) { return 0UL; }
+static inline void __restore_user_access(unsigned long flags) { }
 #endif /* CONFIG_PPC_BOOK3S_64 */
 #endif /* CONFIG_PPC_KUAP */
 
+static __always_inline bool
+bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
+{
+	return __bad_kuap_fault(regs, address, is_write);
+}
+
+static __always_inline void kuap_assert_locked(void)
+{
+	__kuap_assert_locked();
+}
+
+#ifdef CONFIG_PPC32
+static __always_inline void kuap_save_and_lock(struct pt_regs *regs)
+{
+	__kuap_save_and_lock(regs);
+}
+#endif
+
+static __always_inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long amr)
+{
+	__kuap_kernel_restore(regs, amr);
+}
+
+static __always_inline unsigned long kuap_get_and_assert_locked(void)
+{
+	return __kuap_get_and_assert_locked();
+}
+
+#ifndef CONFIG_PPC_BOOK3S_64
+static __always_inline void allow_user_access(void __user *to, const void __user *from,
+				     unsigned long size, unsigned long dir)
+{
+	__allow_user_access(to, from, size, dir);
+}
+
+static __always_inline void prevent_user_access(unsigned long dir)
+{
+	__prevent_user_access(dir);
+}
+
+static __always_inline unsigned long prevent_user_access_return(void)
+{
+	return __prevent_user_access_return();
+}
+
+static __always_inline void restore_user_access(unsigned long flags)
+{
+	__restore_user_access(flags);
+}
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
 static __always_inline void setup_kup(void)
 {
 	setup_kuep(disable_kuep);
diff --git a/arch/powerpc/include/asm/nohash/32/kup-8xx.h b/arch/powerpc/include/asm/nohash/32/kup-8xx.h
index 882a0bc7887a..a5db84164afd 100644
--- a/arch/powerpc/include/asm/nohash/32/kup-8xx.h
+++ b/arch/powerpc/include/asm/nohash/32/kup-8xx.h
@@ -20,7 +20,7 @@ static __always_inline bool kuap_is_disabled(void)
 	return static_branch_unlikely(&disable_kuap_key);
 }
 
-static inline void kuap_save_and_lock(struct pt_regs *regs)
+static inline void __kuap_save_and_lock(struct pt_regs *regs)
 {
 	if (kuap_is_disabled())
 		return;
@@ -33,7 +33,7 @@ static inline void kuap_user_restore(struct pt_regs *regs)
 {
 }
 
-static inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
+static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
 {
 	if (kuap_is_disabled())
 		return;
@@ -41,7 +41,7 @@ static inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
 	mtspr(SPRN_MD_AP, regs->kuap);
 }
 
-static inline unsigned long kuap_get_and_assert_locked(void)
+static inline unsigned long __kuap_get_and_assert_locked(void)
 {
 	unsigned long kuap;
 
@@ -56,14 +56,14 @@ static inline unsigned long kuap_get_and_assert_locked(void)
 	return kuap;
 }
 
-static inline void kuap_assert_locked(void)
+static inline void __kuap_assert_locked(void)
 {
 	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && !kuap_is_disabled())
 		kuap_get_and_assert_locked();
 }
 
-static inline void allow_user_access(void __user *to, const void __user *from,
-				     unsigned long size, unsigned long dir)
+static inline void __allow_user_access(void __user *to, const void __user *from,
+				       unsigned long size, unsigned long dir)
 {
 	if (kuap_is_disabled())
 		return;
@@ -71,7 +71,7 @@ static inline void allow_user_access(void __user *to, const void __user *from,
 	mtspr(SPRN_MD_AP, MD_APG_INIT);
 }
 
-static inline void prevent_user_access(unsigned long dir)
+static inline void __prevent_user_access(unsigned long dir)
 {
 	if (kuap_is_disabled())
 		return;
@@ -79,7 +79,7 @@ static inline void prevent_user_access(unsigned long dir)
 	mtspr(SPRN_MD_AP, MD_APG_KUAP);
 }
 
-static inline unsigned long prevent_user_access_return(void)
+static inline unsigned long __prevent_user_access_return(void)
 {
 	unsigned long flags;
 
@@ -93,7 +93,7 @@ static inline unsigned long prevent_user_access_return(void)
 	return flags;
 }
 
-static inline void restore_user_access(unsigned long flags)
+static inline void __restore_user_access(unsigned long flags)
 {
 	if (kuap_is_disabled())
 		return;
@@ -102,7 +102,7 @@ static inline void restore_user_access(unsigned long flags)
 }
 
 static inline bool
-bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
+__bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
 {
 	if (kuap_is_disabled())
 		return false;
-- 
2.31.1

[PATCH v1 04/15] powerpc/kuap: Check KUAP activation in generic functions

[Christophe Leroy]

Today, every platform checks that KUAP is not de-activated
before doing the real job.

Move the verification out of platform specific functions.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/book3s/32/kup.h     | 34 +++-------------
 arch/powerpc/include/asm/book3s/64/kup.h     | 41 ++++++++++----------
 arch/powerpc/include/asm/kup.h               | 26 +++++++++++++
 arch/powerpc/include/asm/nohash/32/kup-8xx.h | 28 +------------
 4 files changed, 53 insertions(+), 76 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h
index c49fbe0418be..d2685fa09fed 100644
--- a/arch/powerpc/include/asm/book3s/32/kup.h
+++ b/arch/powerpc/include/asm/book3s/32/kup.h
@@ -16,11 +16,6 @@ extern struct static_key_false disable_kuep_key;
 
 extern s32 patch__kuep_lock, patch__kuep_unlock;
 
-static __always_inline bool kuap_is_disabled(void)
-{
-	return !IS_ENABLED(CONFIG_PPC_KUAP) || static_branch_unlikely(&disable_kuap_key);
-}
-
 static __always_inline bool kuep_is_disabled(void)
 {
 	return !IS_ENABLED(CONFIG_PPC_KUEP) || static_branch_unlikely(&disable_kuep_key);
@@ -33,6 +28,11 @@ static __always_inline bool kuep_is_disabled(void)
 #define KUAP_NONE	(~0UL)
 #define KUAP_ALL	(~1UL)
 
+static __always_inline bool kuap_is_disabled(void)
+{
+	return static_branch_unlikely(&disable_kuap_key);
+}
+
 static inline void kuap_lock_one(unsigned long addr)
 {
 	mtsr(mfsr(addr) | SR_KS, addr);
@@ -84,9 +84,6 @@ static inline void __kuap_save_and_lock(struct pt_regs *regs)
 {
 	unsigned long kuap = current->thread.kuap;
 
-	if (kuap_is_disabled())
-		return;
-
 	regs->kuap = kuap;
 	if (unlikely(kuap == KUAP_NONE))
 		return;
@@ -101,9 +98,6 @@ static inline void kuap_user_restore(struct pt_regs *regs)
 
 static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
 {
-	if (kuap_is_disabled())
-		return;
-
 	current->thread.kuap = regs->kuap;
 
 	kuap_unlock(regs->kuap, false);
@@ -113,9 +107,6 @@ static inline unsigned long __kuap_get_and_assert_locked(void)
 {
 	unsigned long kuap = current->thread.kuap;
 
-	if (kuap_is_disabled())
-		return KUAP_NONE;
-
 	WARN_ON_ONCE(IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && kuap != KUAP_NONE);
 
 	return kuap;
@@ -129,9 +120,6 @@ static inline void __kuap_assert_locked(void)
 static __always_inline void __allow_user_access(void __user *to, const void __user *from,
 						u32 size, unsigned long dir)
 {
-	if (kuap_is_disabled())
-		return;
-
 	BUILD_BUG_ON(!__builtin_constant_p(dir));
 
 	if (!(dir & KUAP_WRITE))
@@ -145,9 +133,6 @@ static __always_inline void __prevent_user_access(unsigned long dir)
 {
 	u32 kuap = current->thread.kuap;
 
-	if (kuap_is_disabled())
-		return;
-
 	BUILD_BUG_ON(!__builtin_constant_p(dir));
 
 	if (!(dir & KUAP_WRITE))
@@ -161,9 +146,6 @@ static inline unsigned long __prevent_user_access_return(void)
 {
 	unsigned long flags = current->thread.kuap;
 
-	if (kuap_is_disabled())
-		return KUAP_NONE;
-
 	if (flags != KUAP_NONE) {
 		current->thread.kuap = KUAP_NONE;
 		kuap_lock(flags, true);
@@ -174,9 +156,6 @@ static inline unsigned long __prevent_user_access_return(void)
 
 static inline void __restore_user_access(unsigned long flags)
 {
-	if (kuap_is_disabled())
-		return;
-
 	if (flags != KUAP_NONE) {
 		current->thread.kuap = flags;
 		kuap_unlock(flags, true);
@@ -188,9 +167,6 @@ __bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
 {
 	unsigned long kuap = regs->kuap;
 
-	if (kuap_is_disabled())
-		return false;
-
 	if (!is_write || kuap == KUAP_ALL)
 		return false;
 	if (kuap == KUAP_NONE)
diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index 03d61c5205a4..9f2099790658 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -229,6 +229,11 @@ static inline u64 current_thread_iamr(void)
 
 #ifdef CONFIG_PPC_KUAP
 
+static __always_inline bool kuap_is_disabled(void)
+{
+	return !mmu_has_feature(MMU_FTR_BOOK3S_KUAP);
+}
+
 static inline void kuap_user_restore(struct pt_regs *regs)
 {
 	bool restore_amr = false, restore_iamr = false;
@@ -270,36 +275,32 @@ static inline void kuap_user_restore(struct pt_regs *regs)
 
 static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long amr)
 {
-	if (mmu_has_feature(MMU_FTR_BOOK3S_KUAP)) {
-		if (unlikely(regs->amr != amr)) {
-			isync();
-			mtspr(SPRN_AMR, regs->amr);
-			/*
-			 * No isync required here because we are about to rfi
-			 * back to previous context before any user accesses
-			 * would be made, which is a CSI.
-			 */
-		}
-	}
+	if (likely(regs->amr == amr))
+		return;
+
+	isync();
+	mtspr(SPRN_AMR, regs->amr);
 	/*
+	 * No isync required here because we are about to rfi
+	 * back to previous context before any user accesses
+	 * would be made, which is a CSI.
+	 *
 	 * No need to restore IAMR when returning to kernel space.
 	 */
 }
 
 static inline unsigned long __kuap_get_and_assert_locked(void)
 {
-	if (mmu_has_feature(MMU_FTR_BOOK3S_KUAP)) {
-		unsigned long amr = mfspr(SPRN_AMR);
-		if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG)) /* kuap_check_amr() */
-			WARN_ON_ONCE(amr != AMR_KUAP_BLOCKED);
-		return amr;
-	}
-	return 0;
+	unsigned long amr = mfspr(SPRN_AMR);
+
+	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG)) /* kuap_check_amr() */
+		WARN_ON_ONCE(amr != AMR_KUAP_BLOCKED);
+	return amr;
 }
 
 static inline void __kuap_assert_locked(void)
 {
-	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && mmu_has_feature(MMU_FTR_BOOK3S_KUAP))
+	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG))
 		WARN_ON_ONCE(mfspr(SPRN_AMR) != AMR_KUAP_BLOCKED);
 }
 
@@ -340,8 +341,6 @@ static inline void set_kuap(unsigned long value)
 
 static inline bool __bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
 {
-	if (!mmu_has_feature(MMU_FTR_BOOK3S_KUAP))
-		return false;
 	/*
 	 * For radix this will be a storage protection fault (DSISR_PROTFAULT).
 	 * For hash this will be a key fault (DSISR_KEYFAULT)
diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index 3dbd3f77b413..3a7e2ca9f6ee 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -43,6 +43,8 @@ void setup_kuap(bool disabled);
 #else
 static inline void setup_kuap(bool disabled) { }
 
+static __always_inline bool kuap_is_disabled(void) { return true; }
+
 static inline bool
 __bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
 {
@@ -81,23 +83,35 @@ bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
 
 static __always_inline void kuap_assert_locked(void)
 {
+	if (kuap_is_disabled())
+		return;
+
 	__kuap_assert_locked();
 }
 
 #ifdef CONFIG_PPC32
 static __always_inline void kuap_save_and_lock(struct pt_regs *regs)
 {
+	if (kuap_is_disabled())
+		return;
+
 	__kuap_save_and_lock(regs);
 }
 #endif
 
 static __always_inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long amr)
 {
+	if (kuap_is_disabled())
+		return;
+
 	__kuap_kernel_restore(regs, amr);
 }
 
 static __always_inline unsigned long kuap_get_and_assert_locked(void)
 {
+	if (kuap_is_disabled())
+		return 0;
+
 	return __kuap_get_and_assert_locked();
 }
 
@@ -105,21 +119,33 @@ static __always_inline unsigned long kuap_get_and_assert_locked(void)
 static __always_inline void allow_user_access(void __user *to, const void __user *from,
 				     unsigned long size, unsigned long dir)
 {
+	if (kuap_is_disabled())
+		return;
+
 	__allow_user_access(to, from, size, dir);
 }
 
 static __always_inline void prevent_user_access(unsigned long dir)
 {
+	if (kuap_is_disabled())
+		return;
+
 	__prevent_user_access(dir);
 }
 
 static __always_inline unsigned long prevent_user_access_return(void)
 {
+	if (kuap_is_disabled())
+		return 0;
+
 	return __prevent_user_access_return();
 }
 
 static __always_inline void restore_user_access(unsigned long flags)
 {
+	if (kuap_is_disabled())
+		return;
+
 	__restore_user_access(flags);
 }
 #endif /* CONFIG_PPC_BOOK3S_64 */
diff --git a/arch/powerpc/include/asm/nohash/32/kup-8xx.h b/arch/powerpc/include/asm/nohash/32/kup-8xx.h
index a5db84164afd..74f15c386476 100644
--- a/arch/powerpc/include/asm/nohash/32/kup-8xx.h
+++ b/arch/powerpc/include/asm/nohash/32/kup-8xx.h
@@ -22,9 +22,6 @@ static __always_inline bool kuap_is_disabled(void)
 
 static inline void __kuap_save_and_lock(struct pt_regs *regs)
 {
-	if (kuap_is_disabled())
-		return;
-
 	regs->kuap = mfspr(SPRN_MD_AP);
 	mtspr(SPRN_MD_AP, MD_APG_KUAP);
 }
@@ -35,9 +32,6 @@ static inline void kuap_user_restore(struct pt_regs *regs)
 
 static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
 {
-	if (kuap_is_disabled())
-		return;
-
 	mtspr(SPRN_MD_AP, regs->kuap);
 }
 
@@ -45,9 +39,6 @@ static inline unsigned long __kuap_get_and_assert_locked(void)
 {
 	unsigned long kuap;
 
-	if (kuap_is_disabled())
-		return MD_APG_INIT;
-
 	kuap = mfspr(SPRN_MD_AP);
 
 	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG))
@@ -58,24 +49,18 @@ static inline unsigned long __kuap_get_and_assert_locked(void)
 
 static inline void __kuap_assert_locked(void)
 {
-	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && !kuap_is_disabled())
-		kuap_get_and_assert_locked();
+	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG))
+		__kuap_get_and_assert_locked();
 }
 
 static inline void __allow_user_access(void __user *to, const void __user *from,
 				       unsigned long size, unsigned long dir)
 {
-	if (kuap_is_disabled())
-		return;
-
 	mtspr(SPRN_MD_AP, MD_APG_INIT);
 }
 
 static inline void __prevent_user_access(unsigned long dir)
 {
-	if (kuap_is_disabled())
-		return;
-
 	mtspr(SPRN_MD_AP, MD_APG_KUAP);
 }
 
@@ -83,9 +68,6 @@ static inline unsigned long __prevent_user_access_return(void)
 {
 	unsigned long flags;
 
-	if (kuap_is_disabled())
-		return MD_APG_INIT;
-
 	flags = mfspr(SPRN_MD_AP);
 
 	mtspr(SPRN_MD_AP, MD_APG_KUAP);
@@ -95,18 +77,12 @@ static inline unsigned long __prevent_user_access_return(void)
 
 static inline void __restore_user_access(unsigned long flags)
 {
-	if (kuap_is_disabled())
-		return;
-
 	mtspr(SPRN_MD_AP, flags);
 }
 
 static inline bool
 __bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
 {
-	if (kuap_is_disabled())
-		return false;
-
 	return !((regs->kuap ^ MD_APG_KUAP) & 0xff000000);
 }
 
-- 
2.31.1

[PATCH v1 04/15] powerpc/kuap: Check KUAP activation in generic functions

[Christophe Leroy]

Today, every platform checks that KUAP is not de-activated
before doing the real job.

Move the verification out of platform specific functions.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/book3s/32/kup.h     | 34 +++-------------
 arch/powerpc/include/asm/book3s/64/kup.h     | 41 ++++++++++----------
 arch/powerpc/include/asm/kup.h               | 26 +++++++++++++
 arch/powerpc/include/asm/nohash/32/kup-8xx.h | 28 +------------
 4 files changed, 53 insertions(+), 76 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h
index c49fbe0418be..d2685fa09fed 100644
--- a/arch/powerpc/include/asm/book3s/32/kup.h
+++ b/arch/powerpc/include/asm/book3s/32/kup.h
@@ -16,11 +16,6 @@ extern struct static_key_false disable_kuep_key;
 
 extern s32 patch__kuep_lock, patch__kuep_unlock;
 
-static __always_inline bool kuap_is_disabled(void)
-{
-	return !IS_ENABLED(CONFIG_PPC_KUAP) || static_branch_unlikely(&disable_kuap_key);
-}
-
 static __always_inline bool kuep_is_disabled(void)
 {
 	return !IS_ENABLED(CONFIG_PPC_KUEP) || static_branch_unlikely(&disable_kuep_key);
@@ -33,6 +28,11 @@ static __always_inline bool kuep_is_disabled(void)
 #define KUAP_NONE	(~0UL)
 #define KUAP_ALL	(~1UL)
 
+static __always_inline bool kuap_is_disabled(void)
+{
+	return static_branch_unlikely(&disable_kuap_key);
+}
+
 static inline void kuap_lock_one(unsigned long addr)
 {
 	mtsr(mfsr(addr) | SR_KS, addr);
@@ -84,9 +84,6 @@ static inline void __kuap_save_and_lock(struct pt_regs *regs)
 {
 	unsigned long kuap = current->thread.kuap;
 
-	if (kuap_is_disabled())
-		return;
-
 	regs->kuap = kuap;
 	if (unlikely(kuap == KUAP_NONE))
 		return;
@@ -101,9 +98,6 @@ static inline void kuap_user_restore(struct pt_regs *regs)
 
 static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
 {
-	if (kuap_is_disabled())
-		return;
-
 	current->thread.kuap = regs->kuap;
 
 	kuap_unlock(regs->kuap, false);
@@ -113,9 +107,6 @@ static inline unsigned long __kuap_get_and_assert_locked(void)
 {
 	unsigned long kuap = current->thread.kuap;
 
-	if (kuap_is_disabled())
-		return KUAP_NONE;
-
 	WARN_ON_ONCE(IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && kuap != KUAP_NONE);
 
 	return kuap;
@@ -129,9 +120,6 @@ static inline void __kuap_assert_locked(void)
 static __always_inline void __allow_user_access(void __user *to, const void __user *from,
 						u32 size, unsigned long dir)
 {
-	if (kuap_is_disabled())
-		return;
-
 	BUILD_BUG_ON(!__builtin_constant_p(dir));
 
 	if (!(dir & KUAP_WRITE))
@@ -145,9 +133,6 @@ static __always_inline void __prevent_user_access(unsigned long dir)
 {
 	u32 kuap = current->thread.kuap;
 
-	if (kuap_is_disabled())
-		return;
-
 	BUILD_BUG_ON(!__builtin_constant_p(dir));
 
 	if (!(dir & KUAP_WRITE))
@@ -161,9 +146,6 @@ static inline unsigned long __prevent_user_access_return(void)
 {
 	unsigned long flags = current->thread.kuap;
 
-	if (kuap_is_disabled())
-		return KUAP_NONE;
-
 	if (flags != KUAP_NONE) {
 		current->thread.kuap = KUAP_NONE;
 		kuap_lock(flags, true);
@@ -174,9 +156,6 @@ static inline unsigned long __prevent_user_access_return(void)
 
 static inline void __restore_user_access(unsigned long flags)
 {
-	if (kuap_is_disabled())
-		return;
-
 	if (flags != KUAP_NONE) {
 		current->thread.kuap = flags;
 		kuap_unlock(flags, true);
@@ -188,9 +167,6 @@ __bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
 {
 	unsigned long kuap = regs->kuap;
 
-	if (kuap_is_disabled())
-		return false;
-
 	if (!is_write || kuap == KUAP_ALL)
 		return false;
 	if (kuap == KUAP_NONE)
diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index 03d61c5205a4..9f2099790658 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -229,6 +229,11 @@ static inline u64 current_thread_iamr(void)
 
 #ifdef CONFIG_PPC_KUAP
 
+static __always_inline bool kuap_is_disabled(void)
+{
+	return !mmu_has_feature(MMU_FTR_BOOK3S_KUAP);
+}
+
 static inline void kuap_user_restore(struct pt_regs *regs)
 {
 	bool restore_amr = false, restore_iamr = false;
@@ -270,36 +275,32 @@ static inline void kuap_user_restore(struct pt_regs *regs)
 
 static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long amr)
 {
-	if (mmu_has_feature(MMU_FTR_BOOK3S_KUAP)) {
-		if (unlikely(regs->amr != amr)) {
-			isync();
-			mtspr(SPRN_AMR, regs->amr);
-			/*
-			 * No isync required here because we are about to rfi
-			 * back to previous context before any user accesses
-			 * would be made, which is a CSI.
-			 */
-		}
-	}
+	if (likely(regs->amr == amr))
+		return;
+
+	isync();
+	mtspr(SPRN_AMR, regs->amr);
 	/*
+	 * No isync required here because we are about to rfi
+	 * back to previous context before any user accesses
+	 * would be made, which is a CSI.
+	 *
 	 * No need to restore IAMR when returning to kernel space.
 	 */
 }
 
 static inline unsigned long __kuap_get_and_assert_locked(void)
 {
-	if (mmu_has_feature(MMU_FTR_BOOK3S_KUAP)) {
-		unsigned long amr = mfspr(SPRN_AMR);
-		if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG)) /* kuap_check_amr() */
-			WARN_ON_ONCE(amr != AMR_KUAP_BLOCKED);
-		return amr;
-	}
-	return 0;
+	unsigned long amr = mfspr(SPRN_AMR);
+
+	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG)) /* kuap_check_amr() */
+		WARN_ON_ONCE(amr != AMR_KUAP_BLOCKED);
+	return amr;
 }
 
 static inline void __kuap_assert_locked(void)
 {
-	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && mmu_has_feature(MMU_FTR_BOOK3S_KUAP))
+	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG))
 		WARN_ON_ONCE(mfspr(SPRN_AMR) != AMR_KUAP_BLOCKED);
 }
 
@@ -340,8 +341,6 @@ static inline void set_kuap(unsigned long value)
 
 static inline bool __bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
 {
-	if (!mmu_has_feature(MMU_FTR_BOOK3S_KUAP))
-		return false;
 	/*
 	 * For radix this will be a storage protection fault (DSISR_PROTFAULT).
 	 * For hash this will be a key fault (DSISR_KEYFAULT)
diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index 3dbd3f77b413..3a7e2ca9f6ee 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -43,6 +43,8 @@ void setup_kuap(bool disabled);
 #else
 static inline void setup_kuap(bool disabled) { }
 
+static __always_inline bool kuap_is_disabled(void) { return true; }
+
 static inline bool
 __bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
 {
@@ -81,23 +83,35 @@ bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
 
 static __always_inline void kuap_assert_locked(void)
 {
+	if (kuap_is_disabled())
+		return;
+
 	__kuap_assert_locked();
 }
 
 #ifdef CONFIG_PPC32
 static __always_inline void kuap_save_and_lock(struct pt_regs *regs)
 {
+	if (kuap_is_disabled())
+		return;
+
 	__kuap_save_and_lock(regs);
 }
 #endif
 
 static __always_inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long amr)
 {
+	if (kuap_is_disabled())
+		return;
+
 	__kuap_kernel_restore(regs, amr);
 }
 
 static __always_inline unsigned long kuap_get_and_assert_locked(void)
 {
+	if (kuap_is_disabled())
+		return 0;
+
 	return __kuap_get_and_assert_locked();
 }
 
@@ -105,21 +119,33 @@ static __always_inline unsigned long kuap_get_and_assert_locked(void)
 static __always_inline void allow_user_access(void __user *to, const void __user *from,
 				     unsigned long size, unsigned long dir)
 {
+	if (kuap_is_disabled())
+		return;
+
 	__allow_user_access(to, from, size, dir);
 }
 
 static __always_inline void prevent_user_access(unsigned long dir)
 {
+	if (kuap_is_disabled())
+		return;
+
 	__prevent_user_access(dir);
 }
 
 static __always_inline unsigned long prevent_user_access_return(void)
 {
+	if (kuap_is_disabled())
+		return 0;
+
 	return __prevent_user_access_return();
 }
 
 static __always_inline void restore_user_access(unsigned long flags)
 {
+	if (kuap_is_disabled())
+		return;
+
 	__restore_user_access(flags);
 }
 #endif /* CONFIG_PPC_BOOK3S_64 */
diff --git a/arch/powerpc/include/asm/nohash/32/kup-8xx.h b/arch/powerpc/include/asm/nohash/32/kup-8xx.h
index a5db84164afd..74f15c386476 100644
--- a/arch/powerpc/include/asm/nohash/32/kup-8xx.h
+++ b/arch/powerpc/include/asm/nohash/32/kup-8xx.h
@@ -22,9 +22,6 @@ static __always_inline bool kuap_is_disabled(void)
 
 static inline void __kuap_save_and_lock(struct pt_regs *regs)
 {
-	if (kuap_is_disabled())
-		return;
-
 	regs->kuap = mfspr(SPRN_MD_AP);
 	mtspr(SPRN_MD_AP, MD_APG_KUAP);
 }
@@ -35,9 +32,6 @@ static inline void kuap_user_restore(struct pt_regs *regs)
 
 static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
 {
-	if (kuap_is_disabled())
-		return;
-
 	mtspr(SPRN_MD_AP, regs->kuap);
 }
 
@@ -45,9 +39,6 @@ static inline unsigned long __kuap_get_and_assert_locked(void)
 {
 	unsigned long kuap;
 
-	if (kuap_is_disabled())
-		return MD_APG_INIT;
-
 	kuap = mfspr(SPRN_MD_AP);
 
 	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG))
@@ -58,24 +49,18 @@ static inline unsigned long __kuap_get_and_assert_locked(void)
 
 static inline void __kuap_assert_locked(void)
 {
-	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && !kuap_is_disabled())
-		kuap_get_and_assert_locked();
+	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG))
+		__kuap_get_and_assert_locked();
 }
 
 static inline void __allow_user_access(void __user *to, const void __user *from,
 				       unsigned long size, unsigned long dir)
 {
-	if (kuap_is_disabled())
-		return;
-
 	mtspr(SPRN_MD_AP, MD_APG_INIT);
 }
 
 static inline void __prevent_user_access(unsigned long dir)
 {
-	if (kuap_is_disabled())
-		return;
-
 	mtspr(SPRN_MD_AP, MD_APG_KUAP);
 }
 
@@ -83,9 +68,6 @@ static inline unsigned long __prevent_user_access_return(void)
 {
 	unsigned long flags;
 
-	if (kuap_is_disabled())
-		return MD_APG_INIT;
-
 	flags = mfspr(SPRN_MD_AP);
 
 	mtspr(SPRN_MD_AP, MD_APG_KUAP);
@@ -95,18 +77,12 @@ static inline unsigned long __prevent_user_access_return(void)
 
 static inline void __restore_user_access(unsigned long flags)
 {
-	if (kuap_is_disabled())
-		return;
-
 	mtspr(SPRN_MD_AP, flags);
 }
 
 static inline bool
 __bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
 {
-	if (kuap_is_disabled())
-		return false;
-
 	return !((regs->kuap ^ MD_APG_KUAP) & 0xff000000);
 }
 
-- 
2.31.1

[PATCH v1 05/15] powerpc/kuap: Remove __kuap_assert_locked()

[Christophe Leroy]

__kuap_assert_locked() is redundant with
__kuap_get_and_assert_locked().

Move the verification of CONFIG_PPC_KUAP_DEBUG in kuap_assert_locked()
and make it call __kuap_get_and_assert_locked() directly.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/book3s/32/kup.h     | 5 -----
 arch/powerpc/include/asm/book3s/64/kup.h     | 6 ------
 arch/powerpc/include/asm/kup.h               | 3 ++-
 arch/powerpc/include/asm/nohash/32/kup-8xx.h | 6 ------
 4 files changed, 2 insertions(+), 18 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h
index d2685fa09fed..4404849dfea2 100644
--- a/arch/powerpc/include/asm/book3s/32/kup.h
+++ b/arch/powerpc/include/asm/book3s/32/kup.h
@@ -112,11 +112,6 @@ static inline unsigned long __kuap_get_and_assert_locked(void)
 	return kuap;
 }
 
-static inline void __kuap_assert_locked(void)
-{
-	__kuap_get_and_assert_locked();
-}
-
 static __always_inline void __allow_user_access(void __user *to, const void __user *from,
 						u32 size, unsigned long dir)
 {
diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index 9f2099790658..503828709d55 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -298,12 +298,6 @@ static inline unsigned long __kuap_get_and_assert_locked(void)
 	return amr;
 }
 
-static inline void __kuap_assert_locked(void)
-{
-	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG))
-		WARN_ON_ONCE(mfspr(SPRN_AMR) != AMR_KUAP_BLOCKED);
-}
-
 /*
  * We support individually allowing read or write, but we don't support nesting
  * because that would require an expensive read/modify write of the AMR.
diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index 3a7e2ca9f6ee..43a2c6cb05e3 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -86,7 +86,8 @@ static __always_inline void kuap_assert_locked(void)
 	if (kuap_is_disabled())
 		return;
 
-	__kuap_assert_locked();
+	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG))
+		__kuap_get_and_assert_locked();
 }
 
 #ifdef CONFIG_PPC32
diff --git a/arch/powerpc/include/asm/nohash/32/kup-8xx.h b/arch/powerpc/include/asm/nohash/32/kup-8xx.h
index 74f15c386476..37fe4b32b658 100644
--- a/arch/powerpc/include/asm/nohash/32/kup-8xx.h
+++ b/arch/powerpc/include/asm/nohash/32/kup-8xx.h
@@ -47,12 +47,6 @@ static inline unsigned long __kuap_get_and_assert_locked(void)
 	return kuap;
 }
 
-static inline void __kuap_assert_locked(void)
-{
-	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG))
-		__kuap_get_and_assert_locked();
-}
-
 static inline void __allow_user_access(void __user *to, const void __user *from,
 				       unsigned long size, unsigned long dir)
 {
-- 
2.31.1

[PATCH v1 05/15] powerpc/kuap: Remove __kuap_assert_locked()

[Christophe Leroy]

__kuap_assert_locked() is redundant with
__kuap_get_and_assert_locked().

Move the verification of CONFIG_PPC_KUAP_DEBUG in kuap_assert_locked()
and make it call __kuap_get_and_assert_locked() directly.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/book3s/32/kup.h     | 5 -----
 arch/powerpc/include/asm/book3s/64/kup.h     | 6 ------
 arch/powerpc/include/asm/kup.h               | 3 ++-
 arch/powerpc/include/asm/nohash/32/kup-8xx.h | 6 ------
 4 files changed, 2 insertions(+), 18 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h
index d2685fa09fed..4404849dfea2 100644
--- a/arch/powerpc/include/asm/book3s/32/kup.h
+++ b/arch/powerpc/include/asm/book3s/32/kup.h
@@ -112,11 +112,6 @@ static inline unsigned long __kuap_get_and_assert_locked(void)
 	return kuap;
 }
 
-static inline void __kuap_assert_locked(void)
-{
-	__kuap_get_and_assert_locked();
-}
-
 static __always_inline void __allow_user_access(void __user *to, const void __user *from,
 						u32 size, unsigned long dir)
 {
diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index 9f2099790658..503828709d55 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -298,12 +298,6 @@ static inline unsigned long __kuap_get_and_assert_locked(void)
 	return amr;
 }
 
-static inline void __kuap_assert_locked(void)
-{
-	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG))
-		WARN_ON_ONCE(mfspr(SPRN_AMR) != AMR_KUAP_BLOCKED);
-}
-
 /*
  * We support individually allowing read or write, but we don't support nesting
  * because that would require an expensive read/modify write of the AMR.
diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index 3a7e2ca9f6ee..43a2c6cb05e3 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -86,7 +86,8 @@ static __always_inline void kuap_assert_locked(void)
 	if (kuap_is_disabled())
 		return;
 
-	__kuap_assert_locked();
+	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG))
+		__kuap_get_and_assert_locked();
 }
 
 #ifdef CONFIG_PPC32
diff --git a/arch/powerpc/include/asm/nohash/32/kup-8xx.h b/arch/powerpc/include/asm/nohash/32/kup-8xx.h
index 74f15c386476..37fe4b32b658 100644
--- a/arch/powerpc/include/asm/nohash/32/kup-8xx.h
+++ b/arch/powerpc/include/asm/nohash/32/kup-8xx.h
@@ -47,12 +47,6 @@ static inline unsigned long __kuap_get_and_assert_locked(void)
 	return kuap;
 }
 
-static inline void __kuap_assert_locked(void)
-{
-	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG))
-		__kuap_get_and_assert_locked();
-}
-
 static inline void __allow_user_access(void __user *to, const void __user *from,
 				       unsigned long size, unsigned long dir)
 {
-- 
2.31.1

[PATCH v1 06/15] powerpc/kuap: Add kuap_lock()

[Christophe Leroy]

Add kuap_lock() and call it when entering interrupts from user.

It is called kuap_lock() as it is similar to kuap_save_and_lock()
without the save.

However book3s/32 already have a kuap_lock(). Rename it
kuap_lock_addr().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/book3s/32/kup.h     | 12 ++++++++----
 arch/powerpc/include/asm/interrupt.h         |  5 ++++-
 arch/powerpc/include/asm/kup.h               |  9 +++++++++
 arch/powerpc/include/asm/nohash/32/kup-8xx.h |  4 ++++
 arch/powerpc/kernel/interrupt.c              |  2 ++
 5 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h
index 4404849dfea2..0b68129a060a 100644
--- a/arch/powerpc/include/asm/book3s/32/kup.h
+++ b/arch/powerpc/include/asm/book3s/32/kup.h
@@ -60,7 +60,7 @@ static inline void kuap_unlock_all(void)
 void kuap_lock_all_ool(void);
 void kuap_unlock_all_ool(void);
 
-static inline void kuap_lock(unsigned long addr, bool ool)
+static inline void kuap_lock_addr(unsigned long addr, bool ool)
 {
 	if (likely(addr != KUAP_ALL))
 		kuap_lock_one(addr);
@@ -80,6 +80,10 @@ static inline void kuap_unlock(unsigned long addr, bool ool)
 		kuap_unlock_all_ool();
 }
 
+static inline void __kuap_lock(void)
+{
+}
+
 static inline void __kuap_save_and_lock(struct pt_regs *regs)
 {
 	unsigned long kuap = current->thread.kuap;
@@ -89,7 +93,7 @@ static inline void __kuap_save_and_lock(struct pt_regs *regs)
 		return;
 
 	current->thread.kuap = KUAP_NONE;
-	kuap_lock(kuap, false);
+	kuap_lock_addr(kuap, false);
 }
 
 static inline void kuap_user_restore(struct pt_regs *regs)
@@ -134,7 +138,7 @@ static __always_inline void __prevent_user_access(unsigned long dir)
 		return;
 
 	current->thread.kuap = KUAP_NONE;
-	kuap_lock(kuap, true);
+	kuap_lock_addr(kuap, true);
 }
 
 static inline unsigned long __prevent_user_access_return(void)
@@ -143,7 +147,7 @@ static inline unsigned long __prevent_user_access_return(void)
 
 	if (flags != KUAP_NONE) {
 		current->thread.kuap = KUAP_NONE;
-		kuap_lock(flags, true);
+		kuap_lock_addr(flags, true);
 	}
 
 	return flags;
diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index 03afc4e7928e..6690a41900f2 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -140,9 +140,12 @@ static inline void interrupt_enter_prepare(struct pt_regs *regs, struct interrup
 		trace_hardirqs_off();
 
 	if (user_mode(regs))
-		account_cpu_user_entry();
+		kuap_lock();
 	else
 		kuap_save_and_lock(regs);
+
+	if (user_mode(regs))
+		account_cpu_user_entry();
 #endif
 
 #ifdef CONFIG_PPC64
diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index 43a2c6cb05e3..92b70e18d888 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -52,6 +52,7 @@ __bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
 }
 
 static inline void __kuap_assert_locked(void) { }
+static inline void __kuap_lock(void) { }
 static inline void __kuap_save_and_lock(struct pt_regs *regs) { }
 static inline void kuap_user_restore(struct pt_regs *regs) { }
 static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long amr) { }
@@ -91,6 +92,14 @@ static __always_inline void kuap_assert_locked(void)
 }
 
 #ifdef CONFIG_PPC32
+static __always_inline void kuap_lock(void)
+{
+	if (kuap_is_disabled())
+		return;
+
+	__kuap_lock();
+}
+
 static __always_inline void kuap_save_and_lock(struct pt_regs *regs)
 {
 	if (kuap_is_disabled())
diff --git a/arch/powerpc/include/asm/nohash/32/kup-8xx.h b/arch/powerpc/include/asm/nohash/32/kup-8xx.h
index 37fe4b32b658..c44d97751723 100644
--- a/arch/powerpc/include/asm/nohash/32/kup-8xx.h
+++ b/arch/powerpc/include/asm/nohash/32/kup-8xx.h
@@ -20,6 +20,10 @@ static __always_inline bool kuap_is_disabled(void)
 	return static_branch_unlikely(&disable_kuap_key);
 }
 
+static inline void __kuap_lock(void)
+{
+}
+
 static inline void __kuap_save_and_lock(struct pt_regs *regs)
 {
 	regs->kuap = mfspr(SPRN_MD_AP);
diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
index 0d12aa66e1f9..dc56a514df0a 100644
--- a/arch/powerpc/kernel/interrupt.c
+++ b/arch/powerpc/kernel/interrupt.c
@@ -81,6 +81,8 @@ notrace long system_call_exception(long r3, long r4, long r5,
 {
 	syscall_fn f;
 
+	kuap_lock();
+
 	regs->orig_gpr3 = r3;
 
 	if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
-- 
2.31.1

[PATCH v1 06/15] powerpc/kuap: Add kuap_lock()

[Christophe Leroy]

Add kuap_lock() and call it when entering interrupts from user.

It is called kuap_lock() as it is similar to kuap_save_and_lock()
without the save.

However book3s/32 already have a kuap_lock(). Rename it
kuap_lock_addr().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/book3s/32/kup.h     | 12 ++++++++----
 arch/powerpc/include/asm/interrupt.h         |  5 ++++-
 arch/powerpc/include/asm/kup.h               |  9 +++++++++
 arch/powerpc/include/asm/nohash/32/kup-8xx.h |  4 ++++
 arch/powerpc/kernel/interrupt.c              |  2 ++
 5 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h
index 4404849dfea2..0b68129a060a 100644
--- a/arch/powerpc/include/asm/book3s/32/kup.h
+++ b/arch/powerpc/include/asm/book3s/32/kup.h
@@ -60,7 +60,7 @@ static inline void kuap_unlock_all(void)
 void kuap_lock_all_ool(void);
 void kuap_unlock_all_ool(void);
 
-static inline void kuap_lock(unsigned long addr, bool ool)
+static inline void kuap_lock_addr(unsigned long addr, bool ool)
 {
 	if (likely(addr != KUAP_ALL))
 		kuap_lock_one(addr);
@@ -80,6 +80,10 @@ static inline void kuap_unlock(unsigned long addr, bool ool)
 		kuap_unlock_all_ool();
 }
 
+static inline void __kuap_lock(void)
+{
+}
+
 static inline void __kuap_save_and_lock(struct pt_regs *regs)
 {
 	unsigned long kuap = current->thread.kuap;
@@ -89,7 +93,7 @@ static inline void __kuap_save_and_lock(struct pt_regs *regs)
 		return;
 
 	current->thread.kuap = KUAP_NONE;
-	kuap_lock(kuap, false);
+	kuap_lock_addr(kuap, false);
 }
 
 static inline void kuap_user_restore(struct pt_regs *regs)
@@ -134,7 +138,7 @@ static __always_inline void __prevent_user_access(unsigned long dir)
 		return;
 
 	current->thread.kuap = KUAP_NONE;
-	kuap_lock(kuap, true);
+	kuap_lock_addr(kuap, true);
 }
 
 static inline unsigned long __prevent_user_access_return(void)
@@ -143,7 +147,7 @@ static inline unsigned long __prevent_user_access_return(void)
 
 	if (flags != KUAP_NONE) {
 		current->thread.kuap = KUAP_NONE;
-		kuap_lock(flags, true);
+		kuap_lock_addr(flags, true);
 	}
 
 	return flags;
diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index 03afc4e7928e..6690a41900f2 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -140,9 +140,12 @@ static inline void interrupt_enter_prepare(struct pt_regs *regs, struct interrup
 		trace_hardirqs_off();
 
 	if (user_mode(regs))
-		account_cpu_user_entry();
+		kuap_lock();
 	else
 		kuap_save_and_lock(regs);
+
+	if (user_mode(regs))
+		account_cpu_user_entry();
 #endif
 
 #ifdef CONFIG_PPC64
diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index 43a2c6cb05e3..92b70e18d888 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -52,6 +52,7 @@ __bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
 }
 
 static inline void __kuap_assert_locked(void) { }
+static inline void __kuap_lock(void) { }
 static inline void __kuap_save_and_lock(struct pt_regs *regs) { }
 static inline void kuap_user_restore(struct pt_regs *regs) { }
 static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long amr) { }
@@ -91,6 +92,14 @@ static __always_inline void kuap_assert_locked(void)
 }
 
 #ifdef CONFIG_PPC32
+static __always_inline void kuap_lock(void)
+{
+	if (kuap_is_disabled())
+		return;
+
+	__kuap_lock();
+}
+
 static __always_inline void kuap_save_and_lock(struct pt_regs *regs)
 {
 	if (kuap_is_disabled())
diff --git a/arch/powerpc/include/asm/nohash/32/kup-8xx.h b/arch/powerpc/include/asm/nohash/32/kup-8xx.h
index 37fe4b32b658..c44d97751723 100644
--- a/arch/powerpc/include/asm/nohash/32/kup-8xx.h
+++ b/arch/powerpc/include/asm/nohash/32/kup-8xx.h
@@ -20,6 +20,10 @@ static __always_inline bool kuap_is_disabled(void)
 	return static_branch_unlikely(&disable_kuap_key);
 }
 
+static inline void __kuap_lock(void)
+{
+}
+
 static inline void __kuap_save_and_lock(struct pt_regs *regs)
 {
 	regs->kuap = mfspr(SPRN_MD_AP);
diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
index 0d12aa66e1f9..dc56a514df0a 100644
--- a/arch/powerpc/kernel/interrupt.c
+++ b/arch/powerpc/kernel/interrupt.c
@@ -81,6 +81,8 @@ notrace long system_call_exception(long r3, long r4, long r5,
 {
 	syscall_fn f;
 
+	kuap_lock();
+
 	regs->orig_gpr3 = r3;
 
 	if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
-- 
2.31.1

[PATCH v1 07/15] powerpc/nohash: Move setup_kuap out of 8xx.c

[Christophe Leroy]

In order to reuse it on booke/4xx, move KUAP
setup routine out of 8xx.c

Make them usable on SMP by removing the __init tag
as it is called for each CPU.

And use __prevent_user_access() instead of hard
coding initial lock.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/mm/nohash/8xx.c    | 21 ---------------------
 arch/powerpc/mm/nohash/Makefile |  2 +-
 arch/powerpc/mm/nohash/kup.c    | 32 ++++++++++++++++++++++++++++++++
 3 files changed, 33 insertions(+), 22 deletions(-)
 create mode 100644 arch/powerpc/mm/nohash/kup.c

diff --git a/arch/powerpc/mm/nohash/8xx.c b/arch/powerpc/mm/nohash/8xx.c
index 0df9fe29dd56..e12e41eb91c6 100644
--- a/arch/powerpc/mm/nohash/8xx.c
+++ b/arch/powerpc/mm/nohash/8xx.c
@@ -8,11 +8,7 @@
  */
 
 #include <linux/memblock.h>
-#include <linux/mmu_context.h>
 #include <linux/hugetlb.h>
-#include <asm/fixmap.h>
-#include <asm/code-patching.h>
-#include <asm/inst.h>
 
 #include <mm/mmu_decl.h>
 
@@ -224,23 +220,6 @@ void __init setup_kuep(bool disabled)
 }
 #endif
 
-#ifdef CONFIG_PPC_KUAP
-struct static_key_false disable_kuap_key;
-EXPORT_SYMBOL(disable_kuap_key);
-
-void __init setup_kuap(bool disabled)
-{
-	if (disabled) {
-		static_branch_enable(&disable_kuap_key);
-		return;
-	}
-
-	pr_info("Activating Kernel Userspace Access Protection\n");
-
-	mtspr(SPRN_MD_AP, MD_APG_KUAP);
-}
-#endif
-
 int pud_clear_huge(pud_t *pud)
 {
 	 return 0;
diff --git a/arch/powerpc/mm/nohash/Makefile b/arch/powerpc/mm/nohash/Makefile
index 0424f6ce5bd8..2ffca5f8a169 100644
--- a/arch/powerpc/mm/nohash/Makefile
+++ b/arch/powerpc/mm/nohash/Makefile
@@ -2,7 +2,7 @@
 
 ccflags-$(CONFIG_PPC64)	:= $(NO_MINIMAL_TOC)
 
-obj-y				+= mmu_context.o tlb.o tlb_low.o
+obj-y				+= mmu_context.o tlb.o tlb_low.o kup.o
 obj-$(CONFIG_PPC_BOOK3E_64)  	+= tlb_low_64e.o book3e_pgtable.o
 obj-$(CONFIG_40x)		+= 40x.o
 obj-$(CONFIG_44x)		+= 44x.o
diff --git a/arch/powerpc/mm/nohash/kup.c b/arch/powerpc/mm/nohash/kup.c
new file mode 100644
index 000000000000..bbacbd780806
--- /dev/null
+++ b/arch/powerpc/mm/nohash/kup.c
@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * This file contains the routines for initializing kernel userspace protection
+ */
+
+#include <linux/export.h>
+#include <linux/init.h>
+#include <linux/jump_label.h>
+#include <linux/printk.h>
+#include <linux/smp.h>
+
+#include <asm/kup.h>
+#include <asm/mmu.h>
+#include <asm/smp.h>
+
+#ifdef CONFIG_PPC_KUAP
+struct static_key_false disable_kuap_key;
+EXPORT_SYMBOL(disable_kuap_key);
+
+void setup_kuap(bool disabled)
+{
+	if (disabled) {
+		if (smp_processor_id() == boot_cpuid)
+			static_branch_enable(&disable_kuap_key);
+		return;
+	}
+
+	pr_info("Activating Kernel Userspace Access Protection\n");
+
+	__prevent_user_access(KUAP_READ_WRITE);
+}
+#endif
-- 
2.31.1

[PATCH v1 07/15] powerpc/nohash: Move setup_kuap out of 8xx.c

[Christophe Leroy]

In order to reuse it on booke/4xx, move KUAP
setup routine out of 8xx.c

Make them usable on SMP by removing the __init tag
as it is called for each CPU.

And use __prevent_user_access() instead of hard
coding initial lock.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/mm/nohash/8xx.c    | 21 ---------------------
 arch/powerpc/mm/nohash/Makefile |  2 +-
 arch/powerpc/mm/nohash/kup.c    | 32 ++++++++++++++++++++++++++++++++
 3 files changed, 33 insertions(+), 22 deletions(-)
 create mode 100644 arch/powerpc/mm/nohash/kup.c

diff --git a/arch/powerpc/mm/nohash/8xx.c b/arch/powerpc/mm/nohash/8xx.c
index 0df9fe29dd56..e12e41eb91c6 100644
--- a/arch/powerpc/mm/nohash/8xx.c
+++ b/arch/powerpc/mm/nohash/8xx.c
@@ -8,11 +8,7 @@
  */
 
 #include <linux/memblock.h>
-#include <linux/mmu_context.h>
 #include <linux/hugetlb.h>
-#include <asm/fixmap.h>
-#include <asm/code-patching.h>
-#include <asm/inst.h>
 
 #include <mm/mmu_decl.h>
 
@@ -224,23 +220,6 @@ void __init setup_kuep(bool disabled)
 }
 #endif
 
-#ifdef CONFIG_PPC_KUAP
-struct static_key_false disable_kuap_key;
-EXPORT_SYMBOL(disable_kuap_key);
-
-void __init setup_kuap(bool disabled)
-{
-	if (disabled) {
-		static_branch_enable(&disable_kuap_key);
-		return;
-	}
-
-	pr_info("Activating Kernel Userspace Access Protection\n");
-
-	mtspr(SPRN_MD_AP, MD_APG_KUAP);
-}
-#endif
-
 int pud_clear_huge(pud_t *pud)
 {
 	 return 0;
diff --git a/arch/powerpc/mm/nohash/Makefile b/arch/powerpc/mm/nohash/Makefile
index 0424f6ce5bd8..2ffca5f8a169 100644
--- a/arch/powerpc/mm/nohash/Makefile
+++ b/arch/powerpc/mm/nohash/Makefile
@@ -2,7 +2,7 @@
 
 ccflags-$(CONFIG_PPC64)	:= $(NO_MINIMAL_TOC)
 
-obj-y				+= mmu_context.o tlb.o tlb_low.o
+obj-y				+= mmu_context.o tlb.o tlb_low.o kup.o
 obj-$(CONFIG_PPC_BOOK3E_64)  	+= tlb_low_64e.o book3e_pgtable.o
 obj-$(CONFIG_40x)		+= 40x.o
 obj-$(CONFIG_44x)		+= 44x.o
diff --git a/arch/powerpc/mm/nohash/kup.c b/arch/powerpc/mm/nohash/kup.c
new file mode 100644
index 000000000000..bbacbd780806
--- /dev/null
+++ b/arch/powerpc/mm/nohash/kup.c
@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * This file contains the routines for initializing kernel userspace protection
+ */
+
+#include <linux/export.h>
+#include <linux/init.h>
+#include <linux/jump_label.h>
+#include <linux/printk.h>
+#include <linux/smp.h>
+
+#include <asm/kup.h>
+#include <asm/mmu.h>
+#include <asm/smp.h>
+
+#ifdef CONFIG_PPC_KUAP
+struct static_key_false disable_kuap_key;
+EXPORT_SYMBOL(disable_kuap_key);
+
+void setup_kuap(bool disabled)
+{
+	if (disabled) {
+		if (smp_processor_id() == boot_cpuid)
+			static_branch_enable(&disable_kuap_key);
+		return;
+	}
+
+	pr_info("Activating Kernel Userspace Access Protection\n");
+
+	__prevent_user_access(KUAP_READ_WRITE);
+}
+#endif
-- 
2.31.1

[PATCH v1 08/15] powerpc/config: Add CONFIG_BOOKE_OR_40x

[Christophe Leroy]

We have many functionnalities common to 40x and BOOKE, it leads to
many places with #if defined(CONFIG_BOOKE) || defined(CONFIG_40x).

We are going to add a few more with KUAP for booke/40x, so create
a new symbol which is defined when either BOOKE or 40x is defined.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/hw_irq.h      | 8 ++++----
 arch/powerpc/include/asm/irq.h         | 2 +-
 arch/powerpc/include/asm/ptrace.h      | 2 +-
 arch/powerpc/include/asm/reg.h         | 4 ++--
 arch/powerpc/kernel/asm-offsets.c      | 2 +-
 arch/powerpc/kernel/entry_32.S         | 2 +-
 arch/powerpc/kernel/irq.c              | 2 +-
 arch/powerpc/kernel/kgdb.c             | 4 ++--
 arch/powerpc/kernel/setup.h            | 2 +-
 arch/powerpc/kernel/setup_32.c         | 2 +-
 arch/powerpc/kernel/time.c             | 2 +-
 arch/powerpc/platforms/Kconfig.cputype | 5 +++++
 12 files changed, 21 insertions(+), 16 deletions(-)

diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h
index 21cc571ea9c2..276e9dd7348b 100644
--- a/arch/powerpc/include/asm/hw_irq.h
+++ b/arch/powerpc/include/asm/hw_irq.h
@@ -61,7 +61,7 @@
 
 static inline void __hard_irq_enable(void)
 {
-	if (IS_ENABLED(CONFIG_BOOKE) || IS_ENABLED(CONFIG_40x))
+	if (IS_ENABLED(CONFIG_BOOKE_OR_40x))
 		wrtee(MSR_EE);
 	else if (IS_ENABLED(CONFIG_PPC_8xx))
 		wrtspr(SPRN_EIE);
@@ -73,7 +73,7 @@ static inline void __hard_irq_enable(void)
 
 static inline void __hard_irq_disable(void)
 {
-	if (IS_ENABLED(CONFIG_BOOKE) || IS_ENABLED(CONFIG_40x))
+	if (IS_ENABLED(CONFIG_BOOKE_OR_40x))
 		wrtee(0);
 	else if (IS_ENABLED(CONFIG_PPC_8xx))
 		wrtspr(SPRN_EID);
@@ -85,7 +85,7 @@ static inline void __hard_irq_disable(void)
 
 static inline void __hard_EE_RI_disable(void)
 {
-	if (IS_ENABLED(CONFIG_BOOKE) || IS_ENABLED(CONFIG_40x))
+	if (IS_ENABLED(CONFIG_BOOKE_OR_40x))
 		wrtee(0);
 	else if (IS_ENABLED(CONFIG_PPC_8xx))
 		wrtspr(SPRN_NRI);
@@ -97,7 +97,7 @@ static inline void __hard_EE_RI_disable(void)
 
 static inline void __hard_RI_enable(void)
 {
-	if (IS_ENABLED(CONFIG_BOOKE) || IS_ENABLED(CONFIG_40x))
+	if (IS_ENABLED(CONFIG_BOOKE_OR_40x))
 		return;
 
 	if (IS_ENABLED(CONFIG_PPC_8xx))
diff --git a/arch/powerpc/include/asm/irq.h b/arch/powerpc/include/asm/irq.h
index 2b3278534bc1..13f0409dd617 100644
--- a/arch/powerpc/include/asm/irq.h
+++ b/arch/powerpc/include/asm/irq.h
@@ -36,7 +36,7 @@ extern int distribute_irqs;
 
 struct pt_regs;
 
-#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
+#ifdef CONFIG_BOOKE_OR_40x
 /*
  * Per-cpu stacks for handling critical, debug and machine check
  * level interrupts.
diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index 6e560f035614..42f89e2d8f04 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -291,7 +291,7 @@ static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
 
 static inline bool cpu_has_msr_ri(void)
 {
-	return !IS_ENABLED(CONFIG_BOOKE) && !IS_ENABLED(CONFIG_40x);
+	return !IS_ENABLED(CONFIG_BOOKE_OR_40x);
 }
 
 static inline bool regs_is_unrecoverable(struct pt_regs *regs)
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index e9d27265253b..50478738c8f1 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -18,9 +18,9 @@
 #include <asm/feature-fixups.h>
 
 /* Pickup Book E specific registers. */
-#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
+#ifdef CONFIG_BOOKE_OR_40x
 #include <asm/reg_booke.h>
-#endif /* CONFIG_BOOKE || CONFIG_40x */
+#endif
 
 #ifdef CONFIG_FSL_EMB_PERFMON
 #include <asm/reg_fsl_emb.h>
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index e563d3222d69..cf4a94891bd0 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -56,7 +56,7 @@
 #endif
 
 #ifdef CONFIG_PPC32
-#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
+#ifdef CONFIG_BOOKE_OR_40x
 #include "head_booke.h"
 #endif
 #endif
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 9d31ba2af901..df01da3ca3fa 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -108,7 +108,7 @@ transfer_to_syscall:
 	stw	r11, 0(r1)
 	mflr	r12
 	stw	r12, _LINK(r1)
-#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
+#ifdef CONFIG_BOOKE_OR_40x
 	rlwinm	r9,r9,0,14,12		/* clear MSR_WE (necessary?) */
 #endif
 	lis	r12,STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 551b653228c4..2eb94427d271 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -805,7 +805,7 @@ void __init init_IRQ(void)
 		ppc_md.init_IRQ();
 }
 
-#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
+#ifdef CONFIG_BOOKE_OR_40x
 void   *critirq_ctx[NR_CPUS] __read_mostly;
 void    *dbgirq_ctx[NR_CPUS] __read_mostly;
 void *mcheckirq_ctx[NR_CPUS] __read_mostly;
diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c
index bdee7262c080..9f8d0fa7b718 100644
--- a/arch/powerpc/kernel/kgdb.c
+++ b/arch/powerpc/kernel/kgdb.c
@@ -48,7 +48,7 @@ static struct hard_trap_info
 	{ 0x0800, 0x08 /* SIGFPE */  },		/* fp unavailable */
 	{ 0x0900, 0x0e /* SIGALRM */ },		/* decrementer */
 	{ 0x0c00, 0x14 /* SIGCHLD */ },		/* system call */
-#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
+#ifdef CONFIG_BOOKE_OR_40x
 	{ 0x2002, 0x05 /* SIGTRAP */ },		/* debug */
 #if defined(CONFIG_FSL_BOOKE)
 	{ 0x2010, 0x08 /* SIGFPE */  },		/* spe unavailable */
@@ -67,7 +67,7 @@ static struct hard_trap_info
 	{ 0x2010, 0x08 /* SIGFPE */  },		/* fp unavailable */
 	{ 0x2020, 0x08 /* SIGFPE */  },		/* ap unavailable */
 #endif
-#else /* ! (defined(CONFIG_40x) || defined(CONFIG_BOOKE)) */
+#else /* !CONFIG_BOOKE_OR_40x */
 	{ 0x0d00, 0x05 /* SIGTRAP */ },		/* single-step */
 #if defined(CONFIG_PPC_8xx)
 	{ 0x1000, 0x04 /* SIGILL */  },		/* software emulation */
diff --git a/arch/powerpc/kernel/setup.h b/arch/powerpc/kernel/setup.h
index 84058bbc8fe9..93f22da12abe 100644
--- a/arch/powerpc/kernel/setup.h
+++ b/arch/powerpc/kernel/setup.h
@@ -29,7 +29,7 @@ void setup_tlb_core_data(void);
 static inline void setup_tlb_core_data(void) { }
 #endif
 
-#if defined(CONFIG_PPC_BOOK3E) || defined(CONFIG_BOOKE) || defined(CONFIG_40x)
+#ifdef CONFIG_BOOKE_OR_40x
 void exc_lvl_early_init(void);
 #else
 static inline void exc_lvl_early_init(void) { }
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
index 7ec5c47fce0e..15e7386584f9 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c
@@ -175,7 +175,7 @@ void __init emergency_stack_init(void)
 }
 #endif
 
-#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
+#ifdef CONFIG_BOOKE_OR_40x
 void __init exc_lvl_early_init(void)
 {
 	unsigned int i, hw_cpu;
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 934d8ae66cc6..f7bb2866a1c4 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -738,7 +738,7 @@ static int __init get_freq(char *name, int cells, unsigned long *val)
 
 static void start_cpu_decrementer(void)
 {
-#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
+#ifdef CONFIG_BOOKE_OR_40x
 	unsigned int tcr;
 
 	/* Clear any pending timer interrupts */
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index a208997ade88..dce1cf31047b 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -278,6 +278,11 @@ config BOOKE
 	depends on E500 || 44x || PPC_BOOK3E
 	default y
 
+config BOOKE_OR_40x
+	bool
+	depends on BOOKE || 40x
+	default y
+
 config FSL_BOOKE
 	bool
 	depends on E500 && PPC32
-- 
2.31.1

[PATCH v1 08/15] powerpc/config: Add CONFIG_BOOKE_OR_40x

[Christophe Leroy]

We have many functionnalities common to 40x and BOOKE, it leads to
many places with #if defined(CONFIG_BOOKE) || defined(CONFIG_40x).

We are going to add a few more with KUAP for booke/40x, so create
a new symbol which is defined when either BOOKE or 40x is defined.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/hw_irq.h      | 8 ++++----
 arch/powerpc/include/asm/irq.h         | 2 +-
 arch/powerpc/include/asm/ptrace.h      | 2 +-
 arch/powerpc/include/asm/reg.h         | 4 ++--
 arch/powerpc/kernel/asm-offsets.c      | 2 +-
 arch/powerpc/kernel/entry_32.S         | 2 +-
 arch/powerpc/kernel/irq.c              | 2 +-
 arch/powerpc/kernel/kgdb.c             | 4 ++--
 arch/powerpc/kernel/setup.h            | 2 +-
 arch/powerpc/kernel/setup_32.c         | 2 +-
 arch/powerpc/kernel/time.c             | 2 +-
 arch/powerpc/platforms/Kconfig.cputype | 5 +++++
 12 files changed, 21 insertions(+), 16 deletions(-)

diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h
index 21cc571ea9c2..276e9dd7348b 100644
--- a/arch/powerpc/include/asm/hw_irq.h
+++ b/arch/powerpc/include/asm/hw_irq.h
@@ -61,7 +61,7 @@
 
 static inline void __hard_irq_enable(void)
 {
-	if (IS_ENABLED(CONFIG_BOOKE) || IS_ENABLED(CONFIG_40x))
+	if (IS_ENABLED(CONFIG_BOOKE_OR_40x))
 		wrtee(MSR_EE);
 	else if (IS_ENABLED(CONFIG_PPC_8xx))
 		wrtspr(SPRN_EIE);
@@ -73,7 +73,7 @@ static inline void __hard_irq_enable(void)
 
 static inline void __hard_irq_disable(void)
 {
-	if (IS_ENABLED(CONFIG_BOOKE) || IS_ENABLED(CONFIG_40x))
+	if (IS_ENABLED(CONFIG_BOOKE_OR_40x))
 		wrtee(0);
 	else if (IS_ENABLED(CONFIG_PPC_8xx))
 		wrtspr(SPRN_EID);
@@ -85,7 +85,7 @@ static inline void __hard_irq_disable(void)
 
 static inline void __hard_EE_RI_disable(void)
 {
-	if (IS_ENABLED(CONFIG_BOOKE) || IS_ENABLED(CONFIG_40x))
+	if (IS_ENABLED(CONFIG_BOOKE_OR_40x))
 		wrtee(0);
 	else if (IS_ENABLED(CONFIG_PPC_8xx))
 		wrtspr(SPRN_NRI);
@@ -97,7 +97,7 @@ static inline void __hard_EE_RI_disable(void)
 
 static inline void __hard_RI_enable(void)
 {
-	if (IS_ENABLED(CONFIG_BOOKE) || IS_ENABLED(CONFIG_40x))
+	if (IS_ENABLED(CONFIG_BOOKE_OR_40x))
 		return;
 
 	if (IS_ENABLED(CONFIG_PPC_8xx))
diff --git a/arch/powerpc/include/asm/irq.h b/arch/powerpc/include/asm/irq.h
index 2b3278534bc1..13f0409dd617 100644
--- a/arch/powerpc/include/asm/irq.h
+++ b/arch/powerpc/include/asm/irq.h
@@ -36,7 +36,7 @@ extern int distribute_irqs;
 
 struct pt_regs;
 
-#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
+#ifdef CONFIG_BOOKE_OR_40x
 /*
  * Per-cpu stacks for handling critical, debug and machine check
  * level interrupts.
diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index 6e560f035614..42f89e2d8f04 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -291,7 +291,7 @@ static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
 
 static inline bool cpu_has_msr_ri(void)
 {
-	return !IS_ENABLED(CONFIG_BOOKE) && !IS_ENABLED(CONFIG_40x);
+	return !IS_ENABLED(CONFIG_BOOKE_OR_40x);
 }
 
 static inline bool regs_is_unrecoverable(struct pt_regs *regs)
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index e9d27265253b..50478738c8f1 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -18,9 +18,9 @@
 #include <asm/feature-fixups.h>
 
 /* Pickup Book E specific registers. */
-#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
+#ifdef CONFIG_BOOKE_OR_40x
 #include <asm/reg_booke.h>
-#endif /* CONFIG_BOOKE || CONFIG_40x */
+#endif
 
 #ifdef CONFIG_FSL_EMB_PERFMON
 #include <asm/reg_fsl_emb.h>
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index e563d3222d69..cf4a94891bd0 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -56,7 +56,7 @@
 #endif
 
 #ifdef CONFIG_PPC32
-#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
+#ifdef CONFIG_BOOKE_OR_40x
 #include "head_booke.h"
 #endif
 #endif
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 9d31ba2af901..df01da3ca3fa 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -108,7 +108,7 @@ transfer_to_syscall:
 	stw	r11, 0(r1)
 	mflr	r12
 	stw	r12, _LINK(r1)
-#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
+#ifdef CONFIG_BOOKE_OR_40x
 	rlwinm	r9,r9,0,14,12		/* clear MSR_WE (necessary?) */
 #endif
 	lis	r12,STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 551b653228c4..2eb94427d271 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -805,7 +805,7 @@ void __init init_IRQ(void)
 		ppc_md.init_IRQ();
 }
 
-#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
+#ifdef CONFIG_BOOKE_OR_40x
 void   *critirq_ctx[NR_CPUS] __read_mostly;
 void    *dbgirq_ctx[NR_CPUS] __read_mostly;
 void *mcheckirq_ctx[NR_CPUS] __read_mostly;
diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c
index bdee7262c080..9f8d0fa7b718 100644
--- a/arch/powerpc/kernel/kgdb.c
+++ b/arch/powerpc/kernel/kgdb.c
@@ -48,7 +48,7 @@ static struct hard_trap_info
 	{ 0x0800, 0x08 /* SIGFPE */  },		/* fp unavailable */
 	{ 0x0900, 0x0e /* SIGALRM */ },		/* decrementer */
 	{ 0x0c00, 0x14 /* SIGCHLD */ },		/* system call */
-#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
+#ifdef CONFIG_BOOKE_OR_40x
 	{ 0x2002, 0x05 /* SIGTRAP */ },		/* debug */
 #if defined(CONFIG_FSL_BOOKE)
 	{ 0x2010, 0x08 /* SIGFPE */  },		/* spe unavailable */
@@ -67,7 +67,7 @@ static struct hard_trap_info
 	{ 0x2010, 0x08 /* SIGFPE */  },		/* fp unavailable */
 	{ 0x2020, 0x08 /* SIGFPE */  },		/* ap unavailable */
 #endif
-#else /* ! (defined(CONFIG_40x) || defined(CONFIG_BOOKE)) */
+#else /* !CONFIG_BOOKE_OR_40x */
 	{ 0x0d00, 0x05 /* SIGTRAP */ },		/* single-step */
 #if defined(CONFIG_PPC_8xx)
 	{ 0x1000, 0x04 /* SIGILL */  },		/* software emulation */
diff --git a/arch/powerpc/kernel/setup.h b/arch/powerpc/kernel/setup.h
index 84058bbc8fe9..93f22da12abe 100644
--- a/arch/powerpc/kernel/setup.h
+++ b/arch/powerpc/kernel/setup.h
@@ -29,7 +29,7 @@ void setup_tlb_core_data(void);
 static inline void setup_tlb_core_data(void) { }
 #endif
 
-#if defined(CONFIG_PPC_BOOK3E) || defined(CONFIG_BOOKE) || defined(CONFIG_40x)
+#ifdef CONFIG_BOOKE_OR_40x
 void exc_lvl_early_init(void);
 #else
 static inline void exc_lvl_early_init(void) { }
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
index 7ec5c47fce0e..15e7386584f9 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c
@@ -175,7 +175,7 @@ void __init emergency_stack_init(void)
 }
 #endif
 
-#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
+#ifdef CONFIG_BOOKE_OR_40x
 void __init exc_lvl_early_init(void)
 {
 	unsigned int i, hw_cpu;
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 934d8ae66cc6..f7bb2866a1c4 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -738,7 +738,7 @@ static int __init get_freq(char *name, int cells, unsigned long *val)
 
 static void start_cpu_decrementer(void)
 {
-#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
+#ifdef CONFIG_BOOKE_OR_40x
 	unsigned int tcr;
 
 	/* Clear any pending timer interrupts */
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index a208997ade88..dce1cf31047b 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -278,6 +278,11 @@ config BOOKE
 	depends on E500 || 44x || PPC_BOOK3E
 	default y
 
+config BOOKE_OR_40x
+	bool
+	depends on BOOKE || 40x
+	default y
+
 config FSL_BOOKE
 	bool
 	depends on E500 && PPC32
-- 
2.31.1

[PATCH v1 09/15] powerpc/kuap: Prepare for supporting KUAP on BOOK3E/64

[Christophe Leroy]

Also call kuap_lock() and kuap_save_and_lock() from
interrupt functions with CONFIG_PPC64.

For book3s/64 we keep them empty as it is done in assembly.

Also do the locked assert when switching task unless it is
book3s/64.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/book3s/64/kup.h | 9 +++++++++
 arch/powerpc/include/asm/interrupt.h     | 2 ++
 arch/powerpc/include/asm/kup.h           | 2 --
 arch/powerpc/kernel/process.c            | 6 +++---
 4 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index 503828709d55..69fcf63eec94 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -298,6 +298,15 @@ static inline unsigned long __kuap_get_and_assert_locked(void)
 	return amr;
 }
 
+/* Do nothing, book3s/64 does that in ASM */
+static inline void __kuap_lock(void)
+{
+}
+
+static inline void __kuap_save_and_lock(struct pt_regs *regs)
+{
+}
+
 /*
  * We support individually allowing read or write, but we don't support nesting
  * because that would require an expensive read/modify write of the AMR.
diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index 6690a41900f2..bf7e59f3d17f 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -154,12 +154,14 @@ static inline void interrupt_enter_prepare(struct pt_regs *regs, struct interrup
 	local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
 
 	if (user_mode(regs)) {
+		kuap_lock();
 		CT_WARN_ON(ct_state() != CONTEXT_USER);
 		user_exit_irqoff();
 
 		account_cpu_user_entry();
 		account_stolen_time();
 	} else {
+		kuap_save_and_lock(regs);
 		/*
 		 * CT_WARN_ON comes here via program_check_exception,
 		 * so avoid recursion.
diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index 92b70e18d888..cb9d4a13a9a5 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -91,7 +91,6 @@ static __always_inline void kuap_assert_locked(void)
 		__kuap_get_and_assert_locked();
 }
 
-#ifdef CONFIG_PPC32
 static __always_inline void kuap_lock(void)
 {
 	if (kuap_is_disabled())
@@ -107,7 +106,6 @@ static __always_inline void kuap_save_and_lock(struct pt_regs *regs)
 
 	__kuap_save_and_lock(regs);
 }
-#endif
 
 static __always_inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long amr)
 {
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 50436b52c213..2c637740c0c2 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1281,9 +1281,9 @@ struct task_struct *__switch_to(struct task_struct *prev,
 
 	set_return_regs_changed(); /* _switch changes stack (and regs) */
 
-#ifdef CONFIG_PPC32
-	kuap_assert_locked();
-#endif
+	if (!IS_ENABLED(CONFIG_PPC_BOOK3S_64))
+		kuap_assert_locked();
+
 	last = _switch(old_thread, new_thread);
 
 	/*
-- 
2.31.1

[PATCH v1 09/15] powerpc/kuap: Prepare for supporting KUAP on BOOK3E/64

[Christophe Leroy]

Also call kuap_lock() and kuap_save_and_lock() from
interrupt functions with CONFIG_PPC64.

For book3s/64 we keep them empty as it is done in assembly.

Also do the locked assert when switching task unless it is
book3s/64.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/book3s/64/kup.h | 9 +++++++++
 arch/powerpc/include/asm/interrupt.h     | 2 ++
 arch/powerpc/include/asm/kup.h           | 2 --
 arch/powerpc/kernel/process.c            | 6 +++---
 4 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index 503828709d55..69fcf63eec94 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -298,6 +298,15 @@ static inline unsigned long __kuap_get_and_assert_locked(void)
 	return amr;
 }
 
+/* Do nothing, book3s/64 does that in ASM */
+static inline void __kuap_lock(void)
+{
+}
+
+static inline void __kuap_save_and_lock(struct pt_regs *regs)
+{
+}
+
 /*
  * We support individually allowing read or write, but we don't support nesting
  * because that would require an expensive read/modify write of the AMR.
diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index 6690a41900f2..bf7e59f3d17f 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -154,12 +154,14 @@ static inline void interrupt_enter_prepare(struct pt_regs *regs, struct interrup
 	local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
 
 	if (user_mode(regs)) {
+		kuap_lock();
 		CT_WARN_ON(ct_state() != CONTEXT_USER);
 		user_exit_irqoff();
 
 		account_cpu_user_entry();
 		account_stolen_time();
 	} else {
+		kuap_save_and_lock(regs);
 		/*
 		 * CT_WARN_ON comes here via program_check_exception,
 		 * so avoid recursion.
diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index 92b70e18d888..cb9d4a13a9a5 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -91,7 +91,6 @@ static __always_inline void kuap_assert_locked(void)
 		__kuap_get_and_assert_locked();
 }
 
-#ifdef CONFIG_PPC32
 static __always_inline void kuap_lock(void)
 {
 	if (kuap_is_disabled())
@@ -107,7 +106,6 @@ static __always_inline void kuap_save_and_lock(struct pt_regs *regs)
 
 	__kuap_save_and_lock(regs);
 }
-#endif
 
 static __always_inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long amr)
 {
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 50436b52c213..2c637740c0c2 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1281,9 +1281,9 @@ struct task_struct *__switch_to(struct task_struct *prev,
 
 	set_return_regs_changed(); /* _switch changes stack (and regs) */
 
-#ifdef CONFIG_PPC32
-	kuap_assert_locked();
-#endif
+	if (!IS_ENABLED(CONFIG_PPC_BOOK3S_64))
+		kuap_assert_locked();
+
 	last = _switch(old_thread, new_thread);
 
 	/*
-- 
2.31.1

[PATCH v1 10/15] powerpc: Add KUAP support for BOOKE and 40x

[Christophe Leroy]

On booke/40x we don't have segments like book3s/32.
On booke/40x we don't have access protection groups like 8xx.

Use the PID register to provide user access protection.
Kernel address space can be accessed with any PID.
User address space has to be accessed with the PID of the user.
User PID is always not null.

Everytime the kernel is entered, set PID register to 0 and
restore PID register when returning to user.

Everytime kernel needs to access user data, PID is restored
for the access.

In TLB miss handlers, check the PID and bail out to data storage
exception when PID is 0 and accessed address is in user space.

Note that also forbids execution of user text by kernel except
when user access is unlocked. But this shouldn't be a problem
as the kernel is not supposed to ever run user text.

This patch prepares the infrastructure but the real activation of KUAP
is done by following patches for each processor type one by one.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/kup.h              |   4 +
 arch/powerpc/include/asm/nohash/kup-booke.h | 110 ++++++++++++++++++++
 arch/powerpc/include/asm/processor.h        |   3 +
 arch/powerpc/kernel/process.c               |   3 +
 arch/powerpc/mm/mmu_context.c               |   6 ++
 arch/powerpc/mm/nohash/mmu_context.c        |   6 +-
 6 files changed, 131 insertions(+), 1 deletion(-)
 create mode 100644 arch/powerpc/include/asm/nohash/kup-booke.h

diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index cb9d4a13a9a5..0dd68e97a375 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -14,6 +14,10 @@
 #include <asm/nohash/32/kup-8xx.h>
 #endif
 
+#ifdef CONFIG_BOOKE_OR_40x
+#include <asm/nohash/kup-booke.h>
+#endif
+
 #ifdef CONFIG_PPC_BOOK3S_32
 #include <asm/book3s/32/kup.h>
 #endif
diff --git a/arch/powerpc/include/asm/nohash/kup-booke.h b/arch/powerpc/include/asm/nohash/kup-booke.h
new file mode 100644
index 000000000000..49bb41ed0816
--- /dev/null
+++ b/arch/powerpc/include/asm/nohash/kup-booke.h
@@ -0,0 +1,110 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_POWERPC_KUP_BOOKE_H_
+#define _ASM_POWERPC_KUP_BOOKE_H_
+
+#include <asm/bug.h>
+
+#ifdef CONFIG_PPC_KUAP
+
+#ifdef __ASSEMBLY__
+
+.macro kuap_check_amr	gpr1, gpr2
+.endm
+
+#else
+
+#include <linux/jump_label.h>
+#include <linux/sched.h>
+
+#include <asm/reg.h>
+
+extern struct static_key_false disable_kuap_key;
+
+static __always_inline bool kuap_is_disabled(void)
+{
+	return static_branch_unlikely(&disable_kuap_key);
+}
+
+static inline void __kuap_lock(void)
+{
+	mtspr(SPRN_PID, 0);
+	isync();
+}
+
+static inline void __kuap_save_and_lock(struct pt_regs *regs)
+{
+	regs->kuap = mfspr(SPRN_PID);
+	mtspr(SPRN_PID, 0);
+	isync();
+}
+
+static inline void kuap_user_restore(struct pt_regs *regs)
+{
+	if (kuap_is_disabled())
+		return;
+
+	mtspr(SPRN_PID, current->thread.pid);
+
+	/* Context synchronisation is performed by rfi */
+}
+
+static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
+{
+	if (regs->kuap)
+		mtspr(SPRN_PID, current->thread.pid);
+
+	/* Context synchronisation is performed by rfi */
+}
+
+static inline unsigned long __kuap_get_and_assert_locked(void)
+{
+	unsigned long kuap = mfspr(SPRN_PID);
+
+	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG))
+		WARN_ON_ONCE(kuap);
+
+	return kuap;
+}
+
+static inline void __allow_user_access(void __user *to, const void __user *from,
+				       unsigned long size, unsigned long dir)
+{
+	mtspr(SPRN_PID, current->thread.pid);
+	isync();
+}
+
+static inline void __prevent_user_access(unsigned long dir)
+{
+	mtspr(SPRN_PID, 0);
+	isync();
+}
+
+static inline unsigned long __prevent_user_access_return(void)
+{
+	unsigned long flags = mfspr(SPRN_PID);
+
+	mtspr(SPRN_PID, 0);
+	isync();
+
+	return flags;
+}
+
+static inline void __restore_user_access(unsigned long flags)
+{
+	if (flags) {
+		mtspr(SPRN_PID, current->thread.pid);
+		isync();
+	}
+}
+
+static inline bool
+__bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
+{
+	return !regs->kuap;
+}
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* CONFIG_PPC_KUAP */
+
+#endif /* _ASM_POWERPC_KUP_BOOKE_H_ */
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 4b13f94a4f42..2748ae867dbd 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -160,6 +160,9 @@ struct thread_struct {
 	unsigned long	sr0;
 #endif
 #endif /* CONFIG_PPC32 */
+#if defined(CONFIG_BOOKE_OR_40x) && defined(CONFIG_PPC_KUAP)
+	unsigned long	pid;	/* value written in PID reg. at interrupt exit */
+#endif
 	/* Debug Registers */
 	struct debug_reg debug;
 #ifdef CONFIG_PPC_FPU_REGS
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 2c637740c0c2..b22d70681a21 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1767,6 +1767,9 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 #if defined(CONFIG_PPC_BOOK3S_32) && defined(CONFIG_PPC_KUAP)
 	p->thread.kuap = KUAP_NONE;
 #endif
+#if defined(CONFIG_BOOKE_OR_40x) && defined(CONFIG_PPC_KUAP)
+	p->thread.pid = MMU_NO_CONTEXT;
+#endif
 
 	setup_ksp_vsid(p, sp);
 
diff --git a/arch/powerpc/mm/mmu_context.c b/arch/powerpc/mm/mmu_context.c
index e618d5442a28..735c36f26388 100644
--- a/arch/powerpc/mm/mmu_context.c
+++ b/arch/powerpc/mm/mmu_context.c
@@ -21,6 +21,9 @@ static inline void switch_mm_pgdir(struct task_struct *tsk,
 #ifdef CONFIG_PPC_BOOK3S_32
 	tsk->thread.sr0 = mm->context.sr0;
 #endif
+#if defined(CONFIG_BOOKE_OR_40x) && defined(CONFIG_PPC_KUAP)
+	tsk->thread.pid = mm->context.id;
+#endif
 }
 #elif defined(CONFIG_PPC_BOOK3E_64)
 static inline void switch_mm_pgdir(struct task_struct *tsk,
@@ -28,6 +31,9 @@ static inline void switch_mm_pgdir(struct task_struct *tsk,
 {
 	/* 64-bit Book3E keeps track of current PGD in the PACA */
 	get_paca()->pgd = mm->pgd;
+#ifdef CONFIG_PPC_KUAP
+	tsk->thread.pid = mm->context.id;
+#endif
 }
 #else
 static inline void switch_mm_pgdir(struct task_struct *tsk,
diff --git a/arch/powerpc/mm/nohash/mmu_context.c b/arch/powerpc/mm/nohash/mmu_context.c
index 44b2b5e7cabe..85b048f04c56 100644
--- a/arch/powerpc/mm/nohash/mmu_context.c
+++ b/arch/powerpc/mm/nohash/mmu_context.c
@@ -33,6 +33,7 @@
 #include <asm/mmu_context.h>
 #include <asm/tlbflush.h>
 #include <asm/smp.h>
+#include <asm/kup.h>
 
 #include <mm/mmu_decl.h>
 
@@ -217,7 +218,7 @@ static void set_context(unsigned long id, pgd_t *pgd)
 
 		/* sync */
 		mb();
-	} else {
+	} else if (kuap_is_disabled()) {
 		if (IS_ENABLED(CONFIG_40x))
 			mb();	/* sync */
 
@@ -305,6 +306,9 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
 	if (IS_ENABLED(CONFIG_BDI_SWITCH))
 		abatron_pteptrs[1] = next->pgd;
 	set_context(id, next->pgd);
+#if defined(CONFIG_BOOKE_OR_40x) && defined(CONFIG_PPC_KUAP)
+	tsk->thread.pid = id;
+#endif
 	raw_spin_unlock(&context_lock);
 }
 
-- 
2.31.1

[PATCH v1 10/15] powerpc: Add KUAP support for BOOKE and 40x

[Christophe Leroy]

On booke/40x we don't have segments like book3s/32.
On booke/40x we don't have access protection groups like 8xx.

Use the PID register to provide user access protection.
Kernel address space can be accessed with any PID.
User address space has to be accessed with the PID of the user.
User PID is always not null.

Everytime the kernel is entered, set PID register to 0 and
restore PID register when returning to user.

Everytime kernel needs to access user data, PID is restored
for the access.

In TLB miss handlers, check the PID and bail out to data storage
exception when PID is 0 and accessed address is in user space.

Note that also forbids execution of user text by kernel except
when user access is unlocked. But this shouldn't be a problem
as the kernel is not supposed to ever run user text.

This patch prepares the infrastructure but the real activation of KUAP
is done by following patches for each processor type one by one.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/kup.h              |   4 +
 arch/powerpc/include/asm/nohash/kup-booke.h | 110 ++++++++++++++++++++
 arch/powerpc/include/asm/processor.h        |   3 +
 arch/powerpc/kernel/process.c               |   3 +
 arch/powerpc/mm/mmu_context.c               |   6 ++
 arch/powerpc/mm/nohash/mmu_context.c        |   6 +-
 6 files changed, 131 insertions(+), 1 deletion(-)
 create mode 100644 arch/powerpc/include/asm/nohash/kup-booke.h

diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index cb9d4a13a9a5..0dd68e97a375 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -14,6 +14,10 @@
 #include <asm/nohash/32/kup-8xx.h>
 #endif
 
+#ifdef CONFIG_BOOKE_OR_40x
+#include <asm/nohash/kup-booke.h>
+#endif
+
 #ifdef CONFIG_PPC_BOOK3S_32
 #include <asm/book3s/32/kup.h>
 #endif
diff --git a/arch/powerpc/include/asm/nohash/kup-booke.h b/arch/powerpc/include/asm/nohash/kup-booke.h
new file mode 100644
index 000000000000..49bb41ed0816
--- /dev/null
+++ b/arch/powerpc/include/asm/nohash/kup-booke.h
@@ -0,0 +1,110 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_POWERPC_KUP_BOOKE_H_
+#define _ASM_POWERPC_KUP_BOOKE_H_
+
+#include <asm/bug.h>
+
+#ifdef CONFIG_PPC_KUAP
+
+#ifdef __ASSEMBLY__
+
+.macro kuap_check_amr	gpr1, gpr2
+.endm
+
+#else
+
+#include <linux/jump_label.h>
+#include <linux/sched.h>
+
+#include <asm/reg.h>
+
+extern struct static_key_false disable_kuap_key;
+
+static __always_inline bool kuap_is_disabled(void)
+{
+	return static_branch_unlikely(&disable_kuap_key);
+}
+
+static inline void __kuap_lock(void)
+{
+	mtspr(SPRN_PID, 0);
+	isync();
+}
+
+static inline void __kuap_save_and_lock(struct pt_regs *regs)
+{
+	regs->kuap = mfspr(SPRN_PID);
+	mtspr(SPRN_PID, 0);
+	isync();
+}
+
+static inline void kuap_user_restore(struct pt_regs *regs)
+{
+	if (kuap_is_disabled())
+		return;
+
+	mtspr(SPRN_PID, current->thread.pid);
+
+	/* Context synchronisation is performed by rfi */
+}
+
+static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
+{
+	if (regs->kuap)
+		mtspr(SPRN_PID, current->thread.pid);
+
+	/* Context synchronisation is performed by rfi */
+}
+
+static inline unsigned long __kuap_get_and_assert_locked(void)
+{
+	unsigned long kuap = mfspr(SPRN_PID);
+
+	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG))
+		WARN_ON_ONCE(kuap);
+
+	return kuap;
+}
+
+static inline void __allow_user_access(void __user *to, const void __user *from,
+				       unsigned long size, unsigned long dir)
+{
+	mtspr(SPRN_PID, current->thread.pid);
+	isync();
+}
+
+static inline void __prevent_user_access(unsigned long dir)
+{
+	mtspr(SPRN_PID, 0);
+	isync();
+}
+
+static inline unsigned long __prevent_user_access_return(void)
+{
+	unsigned long flags = mfspr(SPRN_PID);
+
+	mtspr(SPRN_PID, 0);
+	isync();
+
+	return flags;
+}
+
+static inline void __restore_user_access(unsigned long flags)
+{
+	if (flags) {
+		mtspr(SPRN_PID, current->thread.pid);
+		isync();
+	}
+}
+
+static inline bool
+__bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
+{
+	return !regs->kuap;
+}
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* CONFIG_PPC_KUAP */
+
+#endif /* _ASM_POWERPC_KUP_BOOKE_H_ */
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 4b13f94a4f42..2748ae867dbd 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -160,6 +160,9 @@ struct thread_struct {
 	unsigned long	sr0;
 #endif
 #endif /* CONFIG_PPC32 */
+#if defined(CONFIG_BOOKE_OR_40x) && defined(CONFIG_PPC_KUAP)
+	unsigned long	pid;	/* value written in PID reg. at interrupt exit */
+#endif
 	/* Debug Registers */
 	struct debug_reg debug;
 #ifdef CONFIG_PPC_FPU_REGS
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 2c637740c0c2..b22d70681a21 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1767,6 +1767,9 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 #if defined(CONFIG_PPC_BOOK3S_32) && defined(CONFIG_PPC_KUAP)
 	p->thread.kuap = KUAP_NONE;
 #endif
+#if defined(CONFIG_BOOKE_OR_40x) && defined(CONFIG_PPC_KUAP)
+	p->thread.pid = MMU_NO_CONTEXT;
+#endif
 
 	setup_ksp_vsid(p, sp);
 
diff --git a/arch/powerpc/mm/mmu_context.c b/arch/powerpc/mm/mmu_context.c
index e618d5442a28..735c36f26388 100644
--- a/arch/powerpc/mm/mmu_context.c
+++ b/arch/powerpc/mm/mmu_context.c
@@ -21,6 +21,9 @@ static inline void switch_mm_pgdir(struct task_struct *tsk,
 #ifdef CONFIG_PPC_BOOK3S_32
 	tsk->thread.sr0 = mm->context.sr0;
 #endif
+#if defined(CONFIG_BOOKE_OR_40x) && defined(CONFIG_PPC_KUAP)
+	tsk->thread.pid = mm->context.id;
+#endif
 }
 #elif defined(CONFIG_PPC_BOOK3E_64)
 static inline void switch_mm_pgdir(struct task_struct *tsk,
@@ -28,6 +31,9 @@ static inline void switch_mm_pgdir(struct task_struct *tsk,
 {
 	/* 64-bit Book3E keeps track of current PGD in the PACA */
 	get_paca()->pgd = mm->pgd;
+#ifdef CONFIG_PPC_KUAP
+	tsk->thread.pid = mm->context.id;
+#endif
 }
 #else
 static inline void switch_mm_pgdir(struct task_struct *tsk,
diff --git a/arch/powerpc/mm/nohash/mmu_context.c b/arch/powerpc/mm/nohash/mmu_context.c
index 44b2b5e7cabe..85b048f04c56 100644
--- a/arch/powerpc/mm/nohash/mmu_context.c
+++ b/arch/powerpc/mm/nohash/mmu_context.c
@@ -33,6 +33,7 @@
 #include <asm/mmu_context.h>
 #include <asm/tlbflush.h>
 #include <asm/smp.h>
+#include <asm/kup.h>
 
 #include <mm/mmu_decl.h>
 
@@ -217,7 +218,7 @@ static void set_context(unsigned long id, pgd_t *pgd)
 
 		/* sync */
 		mb();
-	} else {
+	} else if (kuap_is_disabled()) {
 		if (IS_ENABLED(CONFIG_40x))
 			mb();	/* sync */
 
@@ -305,6 +306,9 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
 	if (IS_ENABLED(CONFIG_BDI_SWITCH))
 		abatron_pteptrs[1] = next->pgd;
 	set_context(id, next->pgd);
+#if defined(CONFIG_BOOKE_OR_40x) && defined(CONFIG_PPC_KUAP)
+	tsk->thread.pid = id;
+#endif
 	raw_spin_unlock(&context_lock);
 }
 
-- 
2.31.1

[PATCH v1 11/15] powerpc/kuap: Wire-up KUAP on 44x

[Christophe Leroy]

This adds KUAP support to 44x. This is done by checking
the content of SPRN_PID at the time it is read and written
into SPRN_MMUCR.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/head_44x.S         | 16 ++++++++++++++++
 arch/powerpc/platforms/Kconfig.cputype |  1 +
 2 files changed, 17 insertions(+)

diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
index 02d2928d1e01..cf92a3434acd 100644
--- a/arch/powerpc/kernel/head_44x.S
+++ b/arch/powerpc/kernel/head_44x.S
@@ -334,6 +334,10 @@ interrupt_base:
 	mfspr	r12,SPRN_MMUCR
 	mfspr   r13,SPRN_PID		/* Get PID */
 	rlwimi	r12,r13,0,24,31		/* Set TID */
+#ifdef CONFIG_PPC_KUAP
+	cmpwi	r13,0
+	beq	2f			/* KUAP Fault */
+#endif
 
 4:
 	mtspr	SPRN_MMUCR,r12
@@ -444,6 +448,10 @@ interrupt_base:
 	mfspr	r12,SPRN_MMUCR
 	mfspr   r13,SPRN_PID		/* Get PID */
 	rlwimi	r12,r13,0,24,31		/* Set TID */
+#ifdef CONFIG_PPC_KUAP
+	cmpwi	r13,0
+	beq	2f			/* KUAP Fault */
+#endif
 
 4:
 	mtspr	SPRN_MMUCR,r12
@@ -575,6 +583,10 @@ finish_tlb_load_44x:
 3:	mfspr	r11,SPRN_SPRG3
 	lwz	r11,PGDIR(r11)
 	mfspr   r12,SPRN_PID		/* Get PID */
+#ifdef CONFIG_PPC_KUAP
+	cmpwi	r12,0
+	beq	2f			/* KUAP Fault */
+#endif
 4:	mtspr	SPRN_MMUCR,r12		/* Set MMUCR */
 
 	/* Mask of required permission bits. Note that while we
@@ -672,6 +684,10 @@ finish_tlb_load_44x:
 3:	mfspr	r11,SPRN_SPRG_THREAD
 	lwz	r11,PGDIR(r11)
 	mfspr   r12,SPRN_PID		/* Get PID */
+#ifdef CONFIG_PPC_KUAP
+	cmpwi	r12,0
+	beq	2f			/* KUAP Fault */
+#endif
 4:	mtspr	SPRN_MMUCR,r12		/* Set MMUCR */
 
 	/* Make up the required permissions */
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index dce1cf31047b..74e5887abbce 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -62,6 +62,7 @@ config 44x
 	select HAVE_PCI
 	select PHYS_64BIT
 	select PPC_HAVE_KUEP
+	select PPC_HAVE_KUAP
 
 endchoice
 
-- 
2.31.1

[PATCH v1 11/15] powerpc/kuap: Wire-up KUAP on 44x

[Christophe Leroy]

This adds KUAP support to 44x. This is done by checking
the content of SPRN_PID at the time it is read and written
into SPRN_MMUCR.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/head_44x.S         | 16 ++++++++++++++++
 arch/powerpc/platforms/Kconfig.cputype |  1 +
 2 files changed, 17 insertions(+)

diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
index 02d2928d1e01..cf92a3434acd 100644
--- a/arch/powerpc/kernel/head_44x.S
+++ b/arch/powerpc/kernel/head_44x.S
@@ -334,6 +334,10 @@ interrupt_base:
 	mfspr	r12,SPRN_MMUCR
 	mfspr   r13,SPRN_PID		/* Get PID */
 	rlwimi	r12,r13,0,24,31		/* Set TID */
+#ifdef CONFIG_PPC_KUAP
+	cmpwi	r13,0
+	beq	2f			/* KUAP Fault */
+#endif
 
 4:
 	mtspr	SPRN_MMUCR,r12
@@ -444,6 +448,10 @@ interrupt_base:
 	mfspr	r12,SPRN_MMUCR
 	mfspr   r13,SPRN_PID		/* Get PID */
 	rlwimi	r12,r13,0,24,31		/* Set TID */
+#ifdef CONFIG_PPC_KUAP
+	cmpwi	r13,0
+	beq	2f			/* KUAP Fault */
+#endif
 
 4:
 	mtspr	SPRN_MMUCR,r12
@@ -575,6 +583,10 @@ finish_tlb_load_44x:
 3:	mfspr	r11,SPRN_SPRG3
 	lwz	r11,PGDIR(r11)
 	mfspr   r12,SPRN_PID		/* Get PID */
+#ifdef CONFIG_PPC_KUAP
+	cmpwi	r12,0
+	beq	2f			/* KUAP Fault */
+#endif
 4:	mtspr	SPRN_MMUCR,r12		/* Set MMUCR */
 
 	/* Mask of required permission bits. Note that while we
@@ -672,6 +684,10 @@ finish_tlb_load_44x:
 3:	mfspr	r11,SPRN_SPRG_THREAD
 	lwz	r11,PGDIR(r11)
 	mfspr   r12,SPRN_PID		/* Get PID */
+#ifdef CONFIG_PPC_KUAP
+	cmpwi	r12,0
+	beq	2f			/* KUAP Fault */
+#endif
 4:	mtspr	SPRN_MMUCR,r12		/* Set MMUCR */
 
 	/* Make up the required permissions */
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index dce1cf31047b..74e5887abbce 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -62,6 +62,7 @@ config 44x
 	select HAVE_PCI
 	select PHYS_64BIT
 	select PPC_HAVE_KUEP
+	select PPC_HAVE_KUAP
 
 endchoice
 
-- 
2.31.1

[PATCH v1 12/15] powerpc/kuap: Wire-up KUAP on 40x

[Christophe Leroy]

This adds KUAP support to 40x. This is done by checking
the content of SPRN_PID at the time user pgtable is loaded.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/head_40x.S         | 8 ++++++++
 arch/powerpc/platforms/Kconfig.cputype | 1 +
 2 files changed, 9 insertions(+)

diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 7d72ee5ab387..87d322dbed94 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -297,6 +297,10 @@ _ASM_NOKPROBE_SYMBOL(\name\()_virt)
 3:
 	mfspr	r11,SPRN_SPRG_THREAD
 	lwz	r11,PGDIR(r11)
+#ifdef CONFIG_PPC_KUAP
+	rlwinm.	r9, r9, 0, 0xff
+	beq	5f			/* Kuap fault */
+#endif
 4:
 	tophys(r11, r11)
 	rlwimi	r11, r10, 12, 20, 29	/* Create L1 (pgdir/pmd) address */
@@ -377,6 +381,10 @@ _ASM_NOKPROBE_SYMBOL(\name\()_virt)
 3:
 	mfspr	r11,SPRN_SPRG_THREAD
 	lwz	r11,PGDIR(r11)
+#ifdef CONFIG_PPC_KUAP
+	rlwinm.	r9, r9, 0, 0xff
+	beq	5f			/* Kuap fault */
+#endif
 4:
 	tophys(r11, r11)
 	rlwimi	r11, r10, 12, 20, 29	/* Create L1 (pgdir/pmd) address */
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 74e5887abbce..3fdc10bc4aab 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -53,6 +53,7 @@ config 40x
 	select PPC_UDBG_16550
 	select 4xx_SOC
 	select HAVE_PCI
+	select PPC_HAVE_KUAP
 
 config 44x
 	bool "AMCC 44x, 46x or 47x"
-- 
2.31.1

[PATCH v1 12/15] powerpc/kuap: Wire-up KUAP on 40x

[Christophe Leroy]

This adds KUAP support to 40x. This is done by checking
the content of SPRN_PID at the time user pgtable is loaded.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/head_40x.S         | 8 ++++++++
 arch/powerpc/platforms/Kconfig.cputype | 1 +
 2 files changed, 9 insertions(+)

diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 7d72ee5ab387..87d322dbed94 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -297,6 +297,10 @@ _ASM_NOKPROBE_SYMBOL(\name\()_virt)
 3:
 	mfspr	r11,SPRN_SPRG_THREAD
 	lwz	r11,PGDIR(r11)
+#ifdef CONFIG_PPC_KUAP
+	rlwinm.	r9, r9, 0, 0xff
+	beq	5f			/* Kuap fault */
+#endif
 4:
 	tophys(r11, r11)
 	rlwimi	r11, r10, 12, 20, 29	/* Create L1 (pgdir/pmd) address */
@@ -377,6 +381,10 @@ _ASM_NOKPROBE_SYMBOL(\name\()_virt)
 3:
 	mfspr	r11,SPRN_SPRG_THREAD
 	lwz	r11,PGDIR(r11)
+#ifdef CONFIG_PPC_KUAP
+	rlwinm.	r9, r9, 0, 0xff
+	beq	5f			/* Kuap fault */
+#endif
 4:
 	tophys(r11, r11)
 	rlwimi	r11, r10, 12, 20, 29	/* Create L1 (pgdir/pmd) address */
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 74e5887abbce..3fdc10bc4aab 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -53,6 +53,7 @@ config 40x
 	select PPC_UDBG_16550
 	select 4xx_SOC
 	select HAVE_PCI
+	select PPC_HAVE_KUAP
 
 config 44x
 	bool "AMCC 44x, 46x or 47x"
-- 
2.31.1

[PATCH v1 13/15] powerpc/kuap: Wire-up KUAP on 85xx in 32 bits mode.

[Christophe Leroy]

This adds KUAP support to 85xx in 32 bits mode.
This is done by reading the content of SPRN_MAS1 and checking
the TID at the time user pgtable is loaded.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/head_fsl_booke.S   | 12 ++++++++++++
 arch/powerpc/platforms/Kconfig.cputype |  1 +
 2 files changed, 13 insertions(+)

diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 0a9a0f301474..44f7271194e5 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -462,6 +462,12 @@ END_BTB_FLUSH_SECTION
 	mfspr	r11,SPRN_SPRG_THREAD
 	lwz	r11,PGDIR(r11)
 
+#ifdef CONFIG_PPC_KUAP
+	mfspr	r12, SPRN_MAS1
+	rlwinm.	r12,r12,0,0x3fff0000
+	beq	2f			/* KUAP fault */
+#endif
+
 4:
 	/* Mask of required permission bits. Note that while we
 	 * do copy ESR:ST to _PAGE_RW position as trying to write
@@ -571,6 +577,12 @@ END_BTB_FLUSH_SECTION
 	mfspr	r11,SPRN_SPRG_THREAD
 	lwz	r11,PGDIR(r11)
 
+#ifdef CONFIG_PPC_KUAP
+	mfspr	r12, SPRN_MAS1
+	rlwinm.	r12,r12,0,0x3fff0000
+	beq	2f			/* KUAP fault */
+#endif
+
 	/* Make up the required permissions for user code */
 #ifdef CONFIG_PTE_64BIT
 	li	r13,_PAGE_PRESENT | _PAGE_BAP_UX
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 3fdc10bc4aab..8152eeba8572 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -37,6 +37,7 @@ config PPC_BOOK3S_32
 config PPC_85xx
 	bool "Freescale 85xx"
 	select E500
+	select PPC_HAVE_KUAP
 
 config PPC_8xx
 	bool "Freescale 8xx"
-- 
2.31.1

[PATCH v1 13/15] powerpc/kuap: Wire-up KUAP on 85xx in 32 bits mode.

[Christophe Leroy]

This adds KUAP support to 85xx in 32 bits mode.
This is done by reading the content of SPRN_MAS1 and checking
the TID at the time user pgtable is loaded.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/head_fsl_booke.S   | 12 ++++++++++++
 arch/powerpc/platforms/Kconfig.cputype |  1 +
 2 files changed, 13 insertions(+)

diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 0a9a0f301474..44f7271194e5 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -462,6 +462,12 @@ END_BTB_FLUSH_SECTION
 	mfspr	r11,SPRN_SPRG_THREAD
 	lwz	r11,PGDIR(r11)
 
+#ifdef CONFIG_PPC_KUAP
+	mfspr	r12, SPRN_MAS1
+	rlwinm.	r12,r12,0,0x3fff0000
+	beq	2f			/* KUAP fault */
+#endif
+
 4:
 	/* Mask of required permission bits. Note that while we
 	 * do copy ESR:ST to _PAGE_RW position as trying to write
@@ -571,6 +577,12 @@ END_BTB_FLUSH_SECTION
 	mfspr	r11,SPRN_SPRG_THREAD
 	lwz	r11,PGDIR(r11)
 
+#ifdef CONFIG_PPC_KUAP
+	mfspr	r12, SPRN_MAS1
+	rlwinm.	r12,r12,0,0x3fff0000
+	beq	2f			/* KUAP fault */
+#endif
+
 	/* Make up the required permissions for user code */
 #ifdef CONFIG_PTE_64BIT
 	li	r13,_PAGE_PRESENT | _PAGE_BAP_UX
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 3fdc10bc4aab..8152eeba8572 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -37,6 +37,7 @@ config PPC_BOOK3S_32
 config PPC_85xx
 	bool "Freescale 85xx"
 	select E500
+	select PPC_HAVE_KUAP
 
 config PPC_8xx
 	bool "Freescale 8xx"
-- 
2.31.1

[PATCH v1 14/15] powerpc/kuap: Wire-up KUAP on book3e/64

[Christophe Leroy]

This adds KUAP support to book3e/64.
This is done by reading the content of SPRN_MAS1 and checking
the TID at the time user pgtable is loaded.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/mm/nohash/tlb_low_64e.S   | 40 ++++++++++++++++++++++----
 arch/powerpc/platforms/Kconfig.cputype |  1 +
 2 files changed, 35 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/mm/nohash/tlb_low_64e.S b/arch/powerpc/mm/nohash/tlb_low_64e.S
index bf24451f3e71..b43524ca2b95 100644
--- a/arch/powerpc/mm/nohash/tlb_low_64e.S
+++ b/arch/powerpc/mm/nohash/tlb_low_64e.S
@@ -128,6 +128,13 @@ END_BTB_FLUSH_SECTION
 
 	bne	tlb_miss_kernel_bolted
 
+tlb_miss_user_bolted:
+#ifdef CONFIG_PPC_KUAP
+	mfspr	r10,SPRN_MAS1
+	rlwinm.	r10,r10,0,0x3fff0000
+	beq-	tlb_miss_fault_bolted /* KUAP fault */
+#endif
+
 tlb_miss_common_bolted:
 /*
  * This is the guts of the TLB miss handler for bolted-linear.
@@ -246,7 +253,7 @@ itlb_miss_fault_bolted:
 
 	cmpldi	cr0,r15,0			/* Check for user region */
 	oris	r11,r11,_PAGE_ACCESSED@h
-	beq	tlb_miss_common_bolted
+	beq	tlb_miss_user_bolted
 	b	itlb_miss_kernel_bolted
 
 #ifdef CONFIG_PPC_FSL_BOOK3E
@@ -676,6 +683,11 @@ finish_normal_tlb_miss:
 	/* Check if required permissions are met */
 	andc.	r15,r11,r14
 	bne-	normal_tlb_miss_access_fault
+#ifdef CONFIG_PPC_KUAP
+	mfspr	r11,SPRN_MAS1
+	rlwinm.	r10,r11,0,0x3fff0000
+	beq-	normal_tlb_miss_access_fault /* KUAP fault */
+#endif
 
 	/* Now we build the MAS:
 	 *
@@ -689,15 +701,17 @@ finish_normal_tlb_miss:
 	 *
 	 * TODO: mix up code below for better scheduling
 	 */
-	clrrdi	r11,r16,12		/* Clear low crap in EA */
-	rlwimi	r11,r14,32-19,27,31	/* Insert WIMGE */
-	mtspr	SPRN_MAS2,r11
+	clrrdi	r10,r16,12		/* Clear low crap in EA */
+	rlwimi	r10,r14,32-19,27,31	/* Insert WIMGE */
+	mtspr	SPRN_MAS2,r10
 
 	/* Check page size, if not standard, update MAS1 */
-	rldicl	r11,r14,64-8,64-8
-	cmpldi	cr0,r11,BOOK3E_PAGESZ_4K
+	rldicl	r10,r14,64-8,64-8
+	cmpldi	cr0,r10,BOOK3E_PAGESZ_4K
 	beq-	1f
+#ifndef CONFIG_PPC_KUAP
 	mfspr	r11,SPRN_MAS1
+#endif
 	rlwimi	r11,r14,31,21,24
 	rlwinm	r11,r11,0,21,19
 	mtspr	SPRN_MAS1,r11
@@ -786,7 +800,16 @@ virt_page_table_tlb_miss:
 	mfspr	r10,SPRN_MAS1
 	rlwinm	r10,r10,0,16,1			/* Clear TID */
 	mtspr	SPRN_MAS1,r10
+#ifdef CONFIG_PPC_KUAP
+	b	2f
+1:
+	mfspr	r10,SPRN_MAS1
+	rlwinm.	r10,r10,0,0x3fff0000
+	beq-	virt_page_table_tlb_miss_fault /* KUAP fault */
+2:
+#else
 1:
+#endif
 BEGIN_MMU_FTR_SECTION
 	/* Search if we already have a TLB entry for that virtual address, and
 	 * if we do, bail out.
@@ -1027,6 +1050,11 @@ virt_page_table_tlb_miss_whacko_fault:
  * avoid too much complication, it will save/restore things for us
  */
 htw_tlb_miss:
+#ifdef CONFIG_PPC_KUAP
+	mfspr	r10,SPRN_MAS1
+	rlwinm.	r10,r10,0,0x3fff0000
+	beq-	htw_tlb_miss_fault /* KUAP fault */
+#endif
 	/* Search if we already have a TLB entry for that virtual address, and
 	 * if we do, bail out.
 	 *
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 8152eeba8572..bd10e176355b 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -118,6 +118,7 @@ config PPC_BOOK3E_64
 	select PPC_SMP_MUXED_IPI
 	select PPC_DOORBELL
 	select ZONE_DMA
+	select PPC_HAVE_KUAP
 
 endchoice
 
-- 
2.31.1

[PATCH v1 14/15] powerpc/kuap: Wire-up KUAP on book3e/64

[Christophe Leroy]

This adds KUAP support to book3e/64.
This is done by reading the content of SPRN_MAS1 and checking
the TID at the time user pgtable is loaded.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/mm/nohash/tlb_low_64e.S   | 40 ++++++++++++++++++++++----
 arch/powerpc/platforms/Kconfig.cputype |  1 +
 2 files changed, 35 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/mm/nohash/tlb_low_64e.S b/arch/powerpc/mm/nohash/tlb_low_64e.S
index bf24451f3e71..b43524ca2b95 100644
--- a/arch/powerpc/mm/nohash/tlb_low_64e.S
+++ b/arch/powerpc/mm/nohash/tlb_low_64e.S
@@ -128,6 +128,13 @@ END_BTB_FLUSH_SECTION
 
 	bne	tlb_miss_kernel_bolted
 
+tlb_miss_user_bolted:
+#ifdef CONFIG_PPC_KUAP
+	mfspr	r10,SPRN_MAS1
+	rlwinm.	r10,r10,0,0x3fff0000
+	beq-	tlb_miss_fault_bolted /* KUAP fault */
+#endif
+
 tlb_miss_common_bolted:
 /*
  * This is the guts of the TLB miss handler for bolted-linear.
@@ -246,7 +253,7 @@ itlb_miss_fault_bolted:
 
 	cmpldi	cr0,r15,0			/* Check for user region */
 	oris	r11,r11,_PAGE_ACCESSED@h
-	beq	tlb_miss_common_bolted
+	beq	tlb_miss_user_bolted
 	b	itlb_miss_kernel_bolted
 
 #ifdef CONFIG_PPC_FSL_BOOK3E
@@ -676,6 +683,11 @@ finish_normal_tlb_miss:
 	/* Check if required permissions are met */
 	andc.	r15,r11,r14
 	bne-	normal_tlb_miss_access_fault
+#ifdef CONFIG_PPC_KUAP
+	mfspr	r11,SPRN_MAS1
+	rlwinm.	r10,r11,0,0x3fff0000
+	beq-	normal_tlb_miss_access_fault /* KUAP fault */
+#endif
 
 	/* Now we build the MAS:
 	 *
@@ -689,15 +701,17 @@ finish_normal_tlb_miss:
 	 *
 	 * TODO: mix up code below for better scheduling
 	 */
-	clrrdi	r11,r16,12		/* Clear low crap in EA */
-	rlwimi	r11,r14,32-19,27,31	/* Insert WIMGE */
-	mtspr	SPRN_MAS2,r11
+	clrrdi	r10,r16,12		/* Clear low crap in EA */
+	rlwimi	r10,r14,32-19,27,31	/* Insert WIMGE */
+	mtspr	SPRN_MAS2,r10
 
 	/* Check page size, if not standard, update MAS1 */
-	rldicl	r11,r14,64-8,64-8
-	cmpldi	cr0,r11,BOOK3E_PAGESZ_4K
+	rldicl	r10,r14,64-8,64-8
+	cmpldi	cr0,r10,BOOK3E_PAGESZ_4K
 	beq-	1f
+#ifndef CONFIG_PPC_KUAP
 	mfspr	r11,SPRN_MAS1
+#endif
 	rlwimi	r11,r14,31,21,24
 	rlwinm	r11,r11,0,21,19
 	mtspr	SPRN_MAS1,r11
@@ -786,7 +800,16 @@ virt_page_table_tlb_miss:
 	mfspr	r10,SPRN_MAS1
 	rlwinm	r10,r10,0,16,1			/* Clear TID */
 	mtspr	SPRN_MAS1,r10
+#ifdef CONFIG_PPC_KUAP
+	b	2f
+1:
+	mfspr	r10,SPRN_MAS1
+	rlwinm.	r10,r10,0,0x3fff0000
+	beq-	virt_page_table_tlb_miss_fault /* KUAP fault */
+2:
+#else
 1:
+#endif
 BEGIN_MMU_FTR_SECTION
 	/* Search if we already have a TLB entry for that virtual address, and
 	 * if we do, bail out.
@@ -1027,6 +1050,11 @@ virt_page_table_tlb_miss_whacko_fault:
  * avoid too much complication, it will save/restore things for us
  */
 htw_tlb_miss:
+#ifdef CONFIG_PPC_KUAP
+	mfspr	r10,SPRN_MAS1
+	rlwinm.	r10,r10,0,0x3fff0000
+	beq-	htw_tlb_miss_fault /* KUAP fault */
+#endif
 	/* Search if we already have a TLB entry for that virtual address, and
 	 * if we do, bail out.
 	 *
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 8152eeba8572..bd10e176355b 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -118,6 +118,7 @@ config PPC_BOOK3E_64
 	select PPC_SMP_MUXED_IPI
 	select PPC_DOORBELL
 	select ZONE_DMA
+	select PPC_HAVE_KUAP
 
 endchoice
 
-- 
2.31.1

[PATCH v1 15/15] powerpc: Remove CONFIG_PPC_HAVE_KUAP

[Christophe Leroy]

All platforms now have KUAP so remove CONFIG_PPC_HAVE_KUAP

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/mm/nohash/kup.c           |  1 -
 arch/powerpc/platforms/Kconfig.cputype | 11 -----------
 2 files changed, 12 deletions(-)

diff --git a/arch/powerpc/mm/nohash/kup.c b/arch/powerpc/mm/nohash/kup.c
index bbacbd780806..eaea52231dd6 100644
--- a/arch/powerpc/mm/nohash/kup.c
+++ b/arch/powerpc/mm/nohash/kup.c
@@ -10,7 +10,6 @@
 #include <linux/smp.h>
 
 #include <asm/kup.h>
-#include <asm/mmu.h>
 #include <asm/smp.h>
 
 #ifdef CONFIG_PPC_KUAP
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index bd10e176355b..f169902415ed 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -31,20 +31,17 @@ config PPC_BOOK3S_32
 	imply PPC_FPU
 	select PPC_HAVE_PMU_SUPPORT
 	select PPC_HAVE_KUEP
-	select PPC_HAVE_KUAP
 	select HAVE_ARCH_VMAP_STACK
 
 config PPC_85xx
 	bool "Freescale 85xx"
 	select E500
-	select PPC_HAVE_KUAP
 
 config PPC_8xx
 	bool "Freescale 8xx"
 	select ARCH_SUPPORTS_HUGETLBFS
 	select FSL_SOC
 	select PPC_HAVE_KUEP
-	select PPC_HAVE_KUAP
 	select HAVE_ARCH_VMAP_STACK
 	select HUGETLBFS
 
@@ -54,7 +51,6 @@ config 40x
 	select PPC_UDBG_16550
 	select 4xx_SOC
 	select HAVE_PCI
-	select PPC_HAVE_KUAP
 
 config 44x
 	bool "AMCC 44x, 46x or 47x"
@@ -64,7 +60,6 @@ config 44x
 	select HAVE_PCI
 	select PHYS_64BIT
 	select PPC_HAVE_KUEP
-	select PPC_HAVE_KUAP
 
 endchoice
 
@@ -110,7 +105,6 @@ config PPC_BOOK3S_64
 	select IRQ_WORK
 	select PPC_MM_SLICES
 	select PPC_HAVE_KUEP
-	select PPC_HAVE_KUAP
 
 config PPC_BOOK3E_64
 	bool "Embedded processors"
@@ -118,7 +112,6 @@ config PPC_BOOK3E_64
 	select PPC_SMP_MUXED_IPI
 	select PPC_DOORBELL
 	select ZONE_DMA
-	select PPC_HAVE_KUAP
 
 endchoice
 
@@ -408,12 +401,8 @@ config PPC_KUEP
 
 	  If you're unsure, say Y.
 
-config PPC_HAVE_KUAP
-	bool
-
 config PPC_KUAP
 	bool "Kernel Userspace Access Protection"
-	depends on PPC_HAVE_KUAP
 	default y
 	help
 	  Enable support for Kernel Userspace Access Protection (KUAP)
-- 
2.31.1

[PATCH v1 15/15] powerpc: Remove CONFIG_PPC_HAVE_KUAP

[Christophe Leroy]

All platforms now have KUAP so remove CONFIG_PPC_HAVE_KUAP

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/mm/nohash/kup.c           |  1 -
 arch/powerpc/platforms/Kconfig.cputype | 11 -----------
 2 files changed, 12 deletions(-)

diff --git a/arch/powerpc/mm/nohash/kup.c b/arch/powerpc/mm/nohash/kup.c
index bbacbd780806..eaea52231dd6 100644
--- a/arch/powerpc/mm/nohash/kup.c
+++ b/arch/powerpc/mm/nohash/kup.c
@@ -10,7 +10,6 @@
 #include <linux/smp.h>
 
 #include <asm/kup.h>
-#include <asm/mmu.h>
 #include <asm/smp.h>
 
 #ifdef CONFIG_PPC_KUAP
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index bd10e176355b..f169902415ed 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -31,20 +31,17 @@ config PPC_BOOK3S_32
 	imply PPC_FPU
 	select PPC_HAVE_PMU_SUPPORT
 	select PPC_HAVE_KUEP
-	select PPC_HAVE_KUAP
 	select HAVE_ARCH_VMAP_STACK
 
 config PPC_85xx
 	bool "Freescale 85xx"
 	select E500
-	select PPC_HAVE_KUAP
 
 config PPC_8xx
 	bool "Freescale 8xx"
 	select ARCH_SUPPORTS_HUGETLBFS
 	select FSL_SOC
 	select PPC_HAVE_KUEP
-	select PPC_HAVE_KUAP
 	select HAVE_ARCH_VMAP_STACK
 	select HUGETLBFS
 
@@ -54,7 +51,6 @@ config 40x
 	select PPC_UDBG_16550
 	select 4xx_SOC
 	select HAVE_PCI
-	select PPC_HAVE_KUAP
 
 config 44x
 	bool "AMCC 44x, 46x or 47x"
@@ -64,7 +60,6 @@ config 44x
 	select HAVE_PCI
 	select PHYS_64BIT
 	select PPC_HAVE_KUEP
-	select PPC_HAVE_KUAP
 
 endchoice
 
@@ -110,7 +105,6 @@ config PPC_BOOK3S_64
 	select IRQ_WORK
 	select PPC_MM_SLICES
 	select PPC_HAVE_KUEP
-	select PPC_HAVE_KUAP
 
 config PPC_BOOK3E_64
 	bool "Embedded processors"
@@ -118,7 +112,6 @@ config PPC_BOOK3E_64
 	select PPC_SMP_MUXED_IPI
 	select PPC_DOORBELL
 	select ZONE_DMA
-	select PPC_HAVE_KUAP
 
 endchoice
 
@@ -408,12 +401,8 @@ config PPC_KUEP
 
 	  If you're unsure, say Y.
 
-config PPC_HAVE_KUAP
-	bool
-
 config PPC_KUAP
 	bool "Kernel Userspace Access Protection"
-	depends on PPC_HAVE_KUAP
 	default y
 	help
 	  Enable support for Kernel Userspace Access Protection (KUAP)
-- 
2.31.1