LinuxPPC-Dev Archive on lore.kernel.org
 help / Atom feed
* [PATCH v13 00/10] powerpc: Switch to CONFIG_THREAD_INFO_IN_TASK
@ 2019-01-12  9:55 Christophe Leroy
  2019-01-12  9:55 ` [PATCH v13 01/10] powerpc/irq: use memblock functions returning virtual address Christophe Leroy
                   ` (11 more replies)
  0 siblings, 12 replies; 16+ messages in thread
From: Christophe Leroy @ 2019-01-12  9:55 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
	Nicholas Piggin, Mike Rapoport
  Cc: linuxppc-dev, linux-kernel

The purpose of this serie is to activate CONFIG_THREAD_INFO_IN_TASK which
moves the thread_info into task_struct.

Moving thread_info into task_struct has the following advantages:
- It protects thread_info from corruption in the case of stack
overflows.
- Its address is harder to determine if stack addresses are
leaked, making a number of attacks more difficult.

Changes since v12:
 - Patch 1: Taken comment from Mike (re-introduced the 'panic' in case memblock allocation fails in setup_64.c
 - Patch 1: Added alloc_stack() function in setup_32.c to also panic in case of allocation failure.

Changes since v11:
 - Rebased on 81775f5563fa ("Automatic merge of branches 'master', 'next' and 'fixes' into merge")
 - Added a first patch to change memblock allocs to functions returning virtual addrs. This removes
   the memset() which were the only remaining stuff in irq_ctx_init() and exc_lvl_ctx_init() at the end.
 - dropping irq_ctx_init() and exc_lvl_ctx_init() in patch 5 (powerpc: Activate CONFIG_THREAD_INFO_IN_TASK)
 - A few cosmetic changes in commit log and code.

Changes since v10:
 - Rebased on 21622a0d2023 ("Automatic merge of branches 'master', 'next' and 'fixes' into merge")
  ==> Fixed conflict in setup_32.S

Changes since v9:
 - Rebased on 183cbf93be88 ("Automatic merge of branches 'master', 'next' and 'fixes' into merge")
  ==> Fixed conflict on xmon

Changes since v8:
 - Rebased on e589b79e40d9 ("Automatic merge of branches 'master', 'next' and 'fixes' into merge")
  ==> Main impact was conflicts due to commit 9a8dd708d547 ("memblock: rename memblock_alloc{_nid,_try_nid} to memblock_phys_alloc*")

Changes since v7:
 - Rebased on fb6c6ce7907d ("Automatic merge of branches 'master', 'next' and 'fixes' into merge")

Changes since v6:
 - Fixed validate_sp() to exclude NULL sp in 'regain entire stack space' patch (early crash with CONFIG_KMEMLEAK)

Changes since v5:
 - Fixed livepatch_sp setup by using end_of_stack() instead of hardcoding
 - Fixed PPC_BPF_LOAD_CPU() macro

Changes since v4:
 - Fixed a build failure on 32bits SMP when include/generated/asm-offsets.h is not
 already existing, was due to spaces instead of a tab in the Makefile

Changes since RFC v3: (based on Nick's review)
 - Renamed task_size.h to task_size_user64.h to better relate to what it contains.
 - Handling of the isolation of thread_info cpu field inside CONFIG_SMP #ifdefs moved to a separate patch.
 - Removed CURRENT_THREAD_INFO macro completely.
 - Added a guard in asm/smp.h to avoid build failure before _TASK_CPU is defined.
 - Added a patch at the end to rename 'tp' pointers to 'sp' pointers
 - Renamed 'tp' into 'sp' pointers in preparation patch when relevant
 - Fixed a few commit logs
 - Fixed checkpatch report.

Changes since RFC v2:
 - Removed the modification of names in asm-offsets
 - Created a rule in arch/powerpc/Makefile to append the offset of current->cpu in CFLAGS
 - Modified asm/smp.h to use the offset set in CFLAGS
 - Squashed the renaming of THREAD_INFO to TASK_STACK in the preparation patch
 - Moved the modification of current_pt_regs in the patch activating CONFIG_THREAD_INFO_IN_TASK

Changes since RFC v1:
 - Removed the first patch which was modifying header inclusion order in timer
 - Modified some names in asm-offsets to avoid conflicts when including asm-offsets in C files
 - Modified asm/smp.h to avoid having to include linux/sched.h (using asm-offsets instead)
 - Moved some changes from the activation patch to the preparation patch.

Christophe Leroy (10):
  powerpc/irq: use memblock functions returning virtual address
  book3s/64: avoid circular header inclusion in mmu-hash.h
  powerpc: Only use task_struct 'cpu' field on SMP
  powerpc: Prepare for moving thread_info into task_struct
  powerpc: Activate CONFIG_THREAD_INFO_IN_TASK
  powerpc: regain entire stack space
  powerpc: 'current_set' is now a table of task_struct pointers
  powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU
  powerpc/64: Remove CURRENT_THREAD_INFO
  powerpc: clean stack pointers naming

 arch/powerpc/Kconfig                           |   1 +
 arch/powerpc/Makefile                          |   7 ++
 arch/powerpc/include/asm/asm-prototypes.h      |   4 +-
 arch/powerpc/include/asm/book3s/64/mmu-hash.h  |   2 +-
 arch/powerpc/include/asm/exception-64s.h       |   4 +-
 arch/powerpc/include/asm/irq.h                 |  18 ++--
 arch/powerpc/include/asm/livepatch.h           |   6 +-
 arch/powerpc/include/asm/processor.h           |  39 +--------
 arch/powerpc/include/asm/ptrace.h              |   2 +-
 arch/powerpc/include/asm/reg.h                 |   2 +-
 arch/powerpc/include/asm/smp.h                 |  17 +++-
 arch/powerpc/include/asm/task_size_user64.h    |  42 +++++++++
 arch/powerpc/include/asm/thread_info.h         |  19 -----
 arch/powerpc/kernel/asm-offsets.c              |  10 ++-
 arch/powerpc/kernel/entry_32.S                 |  66 +++++---------
 arch/powerpc/kernel/entry_64.S                 |  12 +--
 arch/powerpc/kernel/epapr_hcalls.S             |   5 +-
 arch/powerpc/kernel/exceptions-64e.S           |  13 +--
 arch/powerpc/kernel/exceptions-64s.S           |   2 +-
 arch/powerpc/kernel/head_32.S                  |  14 +--
 arch/powerpc/kernel/head_40x.S                 |   4 +-
 arch/powerpc/kernel/head_44x.S                 |   8 +-
 arch/powerpc/kernel/head_64.S                  |   1 +
 arch/powerpc/kernel/head_8xx.S                 |   2 +-
 arch/powerpc/kernel/head_booke.h               |  12 +--
 arch/powerpc/kernel/head_fsl_booke.S           |  16 ++--
 arch/powerpc/kernel/idle_6xx.S                 |   8 +-
 arch/powerpc/kernel/idle_book3e.S              |   2 +-
 arch/powerpc/kernel/idle_e500.S                |   8 +-
 arch/powerpc/kernel/idle_power4.S              |   2 +-
 arch/powerpc/kernel/irq.c                      | 114 +++----------------------
 arch/powerpc/kernel/kgdb.c                     |  28 ------
 arch/powerpc/kernel/machine_kexec_64.c         |   6 +-
 arch/powerpc/kernel/misc_32.S                  |  17 ++--
 arch/powerpc/kernel/process.c                  |  40 ++++-----
 arch/powerpc/kernel/setup-common.c             |   2 +-
 arch/powerpc/kernel/setup_32.c                 |  25 +++---
 arch/powerpc/kernel/setup_64.c                 |  51 +++--------
 arch/powerpc/kernel/smp.c                      |  16 ++--
 arch/powerpc/kernel/trace/ftrace_64_mprofile.S |   6 +-
 arch/powerpc/kvm/book3s_hv_hmi.c               |   1 +
 arch/powerpc/mm/hash_low_32.S                  |  14 ++-
 arch/powerpc/net/bpf_jit32.h                   |   5 +-
 arch/powerpc/sysdev/6xx-suspend.S              |   5 +-
 arch/powerpc/xmon/xmon.c                       |   2 +-
 45 files changed, 249 insertions(+), 431 deletions(-)
 create mode 100644 arch/powerpc/include/asm/task_size_user64.h

-- 
2.13.3


^ permalink raw reply	[flat|nested] 16+ messages in thread

* [PATCH v13 01/10] powerpc/irq: use memblock functions returning virtual address
  2019-01-12  9:55 [PATCH v13 00/10] powerpc: Switch to CONFIG_THREAD_INFO_IN_TASK Christophe Leroy
@ 2019-01-12  9:55 ` Christophe Leroy
  2019-01-12  9:55 ` [PATCH v13 02/10] book3s/64: avoid circular header inclusion in mmu-hash.h Christophe Leroy
                   ` (10 subsequent siblings)
  11 siblings, 0 replies; 16+ messages in thread
From: Christophe Leroy @ 2019-01-12  9:55 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
	Nicholas Piggin, Mike Rapoport
  Cc: linuxppc-dev, linux-kernel

Since only the virtual address of allocated blocks is used,
lets use functions returning directly virtual address.

Those functions have the advantage of also zeroing the block.

Suggested-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/kernel/irq.c      |  5 -----
 arch/powerpc/kernel/setup_32.c | 25 +++++++++++++++----------
 arch/powerpc/kernel/setup_64.c | 19 +++++++------------
 3 files changed, 22 insertions(+), 27 deletions(-)

diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 916ddc4aac44..4a44bc395fbc 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -725,18 +725,15 @@ void exc_lvl_ctx_init(void)
 #endif
 #endif
 
-		memset((void *)critirq_ctx[cpu_nr], 0, THREAD_SIZE);
 		tp = critirq_ctx[cpu_nr];
 		tp->cpu = cpu_nr;
 		tp->preempt_count = 0;
 
 #ifdef CONFIG_BOOKE
-		memset((void *)dbgirq_ctx[cpu_nr], 0, THREAD_SIZE);
 		tp = dbgirq_ctx[cpu_nr];
 		tp->cpu = cpu_nr;
 		tp->preempt_count = 0;
 
-		memset((void *)mcheckirq_ctx[cpu_nr], 0, THREAD_SIZE);
 		tp = mcheckirq_ctx[cpu_nr];
 		tp->cpu = cpu_nr;
 		tp->preempt_count = HARDIRQ_OFFSET;
@@ -754,12 +751,10 @@ void irq_ctx_init(void)
 	int i;
 
 	for_each_possible_cpu(i) {
-		memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 		tp = softirq_ctx[i];
 		tp->cpu = i;
 		klp_init_thread_info(tp);
 
-		memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 		tp = hardirq_ctx[i];
 		tp->cpu = i;
 		klp_init_thread_info(tp);
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
index 947f904688b0..f0e25d845f8c 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c
@@ -196,6 +196,16 @@ static int __init ppc_init(void)
 }
 arch_initcall(ppc_init);
 
+static void *__init alloc_stack(void)
+{
+	void *ptr = memblock_alloc(THREAD_SIZE, THREAD_SIZE);
+
+	if (!ptr)
+		panic("cannot allocate stacks");
+
+	return ptr;
+}
+
 void __init irqstack_early_init(void)
 {
 	unsigned int i;
@@ -203,10 +213,8 @@ void __init irqstack_early_init(void)
 	/* interrupt stacks must be in lowmem, we get that for free on ppc32
 	 * as the memblock is limited to lowmem by default */
 	for_each_possible_cpu(i) {
-		softirq_ctx[i] = (struct thread_info *)
-			__va(memblock_phys_alloc(THREAD_SIZE, THREAD_SIZE));
-		hardirq_ctx[i] = (struct thread_info *)
-			__va(memblock_phys_alloc(THREAD_SIZE, THREAD_SIZE));
+		softirq_ctx[i] = alloc_stack();
+		hardirq_ctx[i] = alloc_stack();
 	}
 }
 
@@ -224,13 +232,10 @@ void __init exc_lvl_early_init(void)
 		hw_cpu = 0;
 #endif
 
-		critirq_ctx[hw_cpu] = (struct thread_info *)
-			__va(memblock_phys_alloc(THREAD_SIZE, THREAD_SIZE));
+		critirq_ctx[hw_cpu] = alloc_stack();
 #ifdef CONFIG_BOOKE
-		dbgirq_ctx[hw_cpu] = (struct thread_info *)
-			__va(memblock_phys_alloc(THREAD_SIZE, THREAD_SIZE));
-		mcheckirq_ctx[hw_cpu] = (struct thread_info *)
-			__va(memblock_phys_alloc(THREAD_SIZE, THREAD_SIZE));
+		dbgirq_ctx[hw_cpu] = alloc_stack();
+		mcheckirq_ctx[hw_cpu] = alloc_stack();
 #endif
 	}
 }
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 236c1151a3a7..080dd515d587 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -634,19 +634,17 @@ __init u64 ppc64_bolted_size(void)
 
 static void *__init alloc_stack(unsigned long limit, int cpu)
 {
-	unsigned long pa;
+	void *ptr;
 
 	BUILD_BUG_ON(STACK_INT_FRAME_SIZE % 16);
 
-	pa = memblock_alloc_base_nid(THREAD_SIZE, THREAD_SIZE, limit,
-					early_cpu_to_node(cpu), MEMBLOCK_NONE);
-	if (!pa) {
-		pa = memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit);
-		if (!pa)
-			panic("cannot allocate stacks");
-	}
+	ptr = memblock_alloc_try_nid(THREAD_SIZE, THREAD_SIZE,
+				     MEMBLOCK_LOW_LIMIT, limit,
+				     early_cpu_to_node(cpu));
+	if (!ptr)
+		panic("cannot allocate stacks");
 
-	return __va(pa);
+	return ptr;
 }
 
 void __init irqstack_early_init(void)
@@ -739,20 +737,17 @@ void __init emergency_stack_init(void)
 		struct thread_info *ti;
 
 		ti = alloc_stack(limit, i);
-		memset(ti, 0, THREAD_SIZE);
 		emerg_stack_init_thread_info(ti, i);
 		paca_ptrs[i]->emergency_sp = (void *)ti + THREAD_SIZE;
 
 #ifdef CONFIG_PPC_BOOK3S_64
 		/* emergency stack for NMI exception handling. */
 		ti = alloc_stack(limit, i);
-		memset(ti, 0, THREAD_SIZE);
 		emerg_stack_init_thread_info(ti, i);
 		paca_ptrs[i]->nmi_emergency_sp = (void *)ti + THREAD_SIZE;
 
 		/* emergency stack for machine check exception handling. */
 		ti = alloc_stack(limit, i);
-		memset(ti, 0, THREAD_SIZE);
 		emerg_stack_init_thread_info(ti, i);
 		paca_ptrs[i]->mc_emergency_sp = (void *)ti + THREAD_SIZE;
 #endif
-- 
2.13.3


^ permalink raw reply	[flat|nested] 16+ messages in thread

* [PATCH v13 02/10] book3s/64: avoid circular header inclusion in mmu-hash.h
  2019-01-12  9:55 [PATCH v13 00/10] powerpc: Switch to CONFIG_THREAD_INFO_IN_TASK Christophe Leroy
  2019-01-12  9:55 ` [PATCH v13 01/10] powerpc/irq: use memblock functions returning virtual address Christophe Leroy
@ 2019-01-12  9:55 ` Christophe Leroy
  2019-01-12  9:55 ` [PATCH v13 03/10] powerpc: Only use task_struct 'cpu' field on SMP Christophe Leroy
                   ` (9 subsequent siblings)
  11 siblings, 0 replies; 16+ messages in thread
From: Christophe Leroy @ 2019-01-12  9:55 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
	Nicholas Piggin, Mike Rapoport
  Cc: linuxppc-dev, linux-kernel

When activating CONFIG_THREAD_INFO_IN_TASK, linux/sched.h
includes asm/current.h. This generates a circular dependency.
To avoid that, asm/processor.h shall not be included in mmu-hash.h

In order to do that, this patch moves into a new header called
asm/task_size_user64.h the information from asm/processor.h required
by mmu-hash.h

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/book3s/64/mmu-hash.h |  2 +-
 arch/powerpc/include/asm/processor.h          | 34 +---------------------
 arch/powerpc/include/asm/task_size_user64.h   | 42 +++++++++++++++++++++++++++
 arch/powerpc/kvm/book3s_hv_hmi.c              |  1 +
 4 files changed, 45 insertions(+), 34 deletions(-)
 create mode 100644 arch/powerpc/include/asm/task_size_user64.h

diff --git a/arch/powerpc/include/asm/book3s/64/mmu-hash.h b/arch/powerpc/include/asm/book3s/64/mmu-hash.h
index 12e522807f9f..b2aba048301e 100644
--- a/arch/powerpc/include/asm/book3s/64/mmu-hash.h
+++ b/arch/powerpc/include/asm/book3s/64/mmu-hash.h
@@ -23,7 +23,7 @@
  */
 #include <asm/book3s/64/pgtable.h>
 #include <asm/bug.h>
-#include <asm/processor.h>
+#include <asm/task_size_user64.h>
 #include <asm/cpu_has_feature.h>
 
 /*
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index ee58526cb6c2..692f7383d461 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -95,40 +95,8 @@ void release_thread(struct task_struct *);
 #endif
 
 #ifdef CONFIG_PPC64
-/*
- * 64-bit user address space can have multiple limits
- * For now supported values are:
- */
-#define TASK_SIZE_64TB  (0x0000400000000000UL)
-#define TASK_SIZE_128TB (0x0000800000000000UL)
-#define TASK_SIZE_512TB (0x0002000000000000UL)
-#define TASK_SIZE_1PB   (0x0004000000000000UL)
-#define TASK_SIZE_2PB   (0x0008000000000000UL)
-/*
- * With 52 bits in the address we can support
- * upto 4PB of range.
- */
-#define TASK_SIZE_4PB   (0x0010000000000000UL)
 
-/*
- * For now 512TB is only supported with book3s and 64K linux page size.
- */
-#if defined(CONFIG_PPC_BOOK3S_64) && defined(CONFIG_PPC_64K_PAGES)
-/*
- * Max value currently used:
- */
-#define TASK_SIZE_USER64		TASK_SIZE_4PB
-#define DEFAULT_MAP_WINDOW_USER64	TASK_SIZE_128TB
-#define TASK_CONTEXT_SIZE		TASK_SIZE_512TB
-#else
-#define TASK_SIZE_USER64		TASK_SIZE_64TB
-#define DEFAULT_MAP_WINDOW_USER64	TASK_SIZE_64TB
-/*
- * We don't need to allocate extended context ids for 4K page size, because
- * we limit the max effective address on this config to 64TB.
- */
-#define TASK_CONTEXT_SIZE		TASK_SIZE_64TB
-#endif
+#include <asm/task_size_user64.h>
 
 /*
  * 32-bit user address space is 4GB - 1 page
diff --git a/arch/powerpc/include/asm/task_size_user64.h b/arch/powerpc/include/asm/task_size_user64.h
new file mode 100644
index 000000000000..a4043075864b
--- /dev/null
+++ b/arch/powerpc/include/asm/task_size_user64.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_POWERPC_TASK_SIZE_USER64_H
+#define _ASM_POWERPC_TASK_SIZE_USER64_H
+
+#ifdef CONFIG_PPC64
+/*
+ * 64-bit user address space can have multiple limits
+ * For now supported values are:
+ */
+#define TASK_SIZE_64TB  (0x0000400000000000UL)
+#define TASK_SIZE_128TB (0x0000800000000000UL)
+#define TASK_SIZE_512TB (0x0002000000000000UL)
+#define TASK_SIZE_1PB   (0x0004000000000000UL)
+#define TASK_SIZE_2PB   (0x0008000000000000UL)
+/*
+ * With 52 bits in the address we can support
+ * upto 4PB of range.
+ */
+#define TASK_SIZE_4PB   (0x0010000000000000UL)
+
+/*
+ * For now 512TB is only supported with book3s and 64K linux page size.
+ */
+#if defined(CONFIG_PPC_BOOK3S_64) && defined(CONFIG_PPC_64K_PAGES)
+/*
+ * Max value currently used:
+ */
+#define TASK_SIZE_USER64		TASK_SIZE_4PB
+#define DEFAULT_MAP_WINDOW_USER64	TASK_SIZE_128TB
+#define TASK_CONTEXT_SIZE		TASK_SIZE_512TB
+#else
+#define TASK_SIZE_USER64		TASK_SIZE_64TB
+#define DEFAULT_MAP_WINDOW_USER64	TASK_SIZE_64TB
+/*
+ * We don't need to allocate extended context ids for 4K page size, because
+ * we limit the max effective address on this config to 64TB.
+ */
+#define TASK_CONTEXT_SIZE		TASK_SIZE_64TB
+#endif
+
+#endif /* CONFIG_PPC64 */
+#endif /* _ASM_POWERPC_TASK_SIZE_USER64_H */
diff --git a/arch/powerpc/kvm/book3s_hv_hmi.c b/arch/powerpc/kvm/book3s_hv_hmi.c
index e3f738eb1cac..64b5011475c7 100644
--- a/arch/powerpc/kvm/book3s_hv_hmi.c
+++ b/arch/powerpc/kvm/book3s_hv_hmi.c
@@ -24,6 +24,7 @@
 #include <linux/compiler.h>
 #include <asm/paca.h>
 #include <asm/hmi.h>
+#include <asm/processor.h>
 
 void wait_for_subcore_guest_exit(void)
 {
-- 
2.13.3


^ permalink raw reply	[flat|nested] 16+ messages in thread

* [PATCH v13 03/10] powerpc: Only use task_struct 'cpu' field on SMP
  2019-01-12  9:55 [PATCH v13 00/10] powerpc: Switch to CONFIG_THREAD_INFO_IN_TASK Christophe Leroy
  2019-01-12  9:55 ` [PATCH v13 01/10] powerpc/irq: use memblock functions returning virtual address Christophe Leroy
  2019-01-12  9:55 ` [PATCH v13 02/10] book3s/64: avoid circular header inclusion in mmu-hash.h Christophe Leroy
@ 2019-01-12  9:55 ` Christophe Leroy
  2019-01-12  9:55 ` [PATCH v13 04/10] powerpc: Prepare for moving thread_info into task_struct Christophe Leroy
                   ` (8 subsequent siblings)
  11 siblings, 0 replies; 16+ messages in thread
From: Christophe Leroy @ 2019-01-12  9:55 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
	Nicholas Piggin, Mike Rapoport
  Cc: linuxppc-dev, linux-kernel

When moving to CONFIG_THREAD_INFO_IN_TASK, the thread_info 'cpu' field
gets moved into task_struct and only defined when CONFIG_SMP is set.

This patch ensures that TI_CPU is only used when CONFIG_SMP is set and
that task_struct 'cpu' field is not used directly out of SMP code.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/head_fsl_booke.S | 2 ++
 arch/powerpc/kernel/misc_32.S        | 4 ++++
 arch/powerpc/xmon/xmon.c             | 2 +-
 3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 2386ce2a9c6e..2c21e8642a00 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -243,8 +243,10 @@ set_ivor:
 	li	r0,0
 	stwu	r0,THREAD_SIZE-STACK_FRAME_OVERHEAD(r1)
 
+#ifdef CONFIG_SMP
 	CURRENT_THREAD_INFO(r22, r1)
 	stw	r24, TI_CPU(r22)
+#endif
 
 	bl	early_init
 
diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index 57d2ffb2d45c..02b8cdd73792 100644
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -183,10 +183,14 @@ _GLOBAL(low_choose_750fx_pll)
 	or	r4,r4,r5
 	mtspr	SPRN_HID1,r4
 
+#ifdef CONFIG_SMP
 	/* Store new HID1 image */
 	CURRENT_THREAD_INFO(r6, r1)
 	lwz	r6,TI_CPU(r6)
 	slwi	r6,r6,2
+#else
+	li	r6, 0
+#endif
 	addis	r6,r6,nap_save_hid1@ha
 	stw	r4,nap_save_hid1@l(r6)
 
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 757b8499aba2..a0f44f992360 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -2997,7 +2997,7 @@ static void show_task(struct task_struct *tsk)
 	printf("%px %016lx %6d %6d %c %2d %s\n", tsk,
 		tsk->thread.ksp,
 		tsk->pid, rcu_dereference(tsk->parent)->pid,
-		state, task_thread_info(tsk)->cpu,
+		state, task_cpu(tsk),
 		tsk->comm);
 }
 
-- 
2.13.3


^ permalink raw reply	[flat|nested] 16+ messages in thread

* [PATCH v13 04/10] powerpc: Prepare for moving thread_info into task_struct
  2019-01-12  9:55 [PATCH v13 00/10] powerpc: Switch to CONFIG_THREAD_INFO_IN_TASK Christophe Leroy
                   ` (2 preceding siblings ...)
  2019-01-12  9:55 ` [PATCH v13 03/10] powerpc: Only use task_struct 'cpu' field on SMP Christophe Leroy
@ 2019-01-12  9:55 ` Christophe Leroy
  2019-01-12  9:55 ` [PATCH v13 05/10] powerpc: Activate CONFIG_THREAD_INFO_IN_TASK Christophe Leroy
                   ` (7 subsequent siblings)
  11 siblings, 0 replies; 16+ messages in thread
From: Christophe Leroy @ 2019-01-12  9:55 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
	Nicholas Piggin, Mike Rapoport
  Cc: linuxppc-dev, linux-kernel

This patch cleans the powerpc kernel before activating
CONFIG_THREAD_INFO_IN_TASK:
- The purpose of the pointer given to call_do_softirq() and
call_do_irq() is to point the new stack ==> change it to void* and
rename it 'sp'
- Don't use CURRENT_THREAD_INFO() to locate the stack.
- Fix a few comments.
- Replace current_thread_info()->task by current
- Rename THREAD_INFO to TASK_STASK: as it is in fact the offset of the
pointer to the stack in task_struct, this pointer will not be impacted
by the move of THREAD_INFO.
- Makes TASK_STACK available to PPC64. PPC64 will need it to get the
stack pointer from current once the thread_info have been moved.
- Modifies klp_init_thread_info() to take task_struct pointer argument.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/irq.h       | 4 ++--
 arch/powerpc/include/asm/livepatch.h | 6 +++---
 arch/powerpc/include/asm/processor.h | 4 ++--
 arch/powerpc/include/asm/reg.h       | 2 +-
 arch/powerpc/kernel/asm-offsets.c    | 2 +-
 arch/powerpc/kernel/entry_32.S       | 2 +-
 arch/powerpc/kernel/entry_64.S       | 2 +-
 arch/powerpc/kernel/head_32.S        | 4 ++--
 arch/powerpc/kernel/head_40x.S       | 4 ++--
 arch/powerpc/kernel/head_44x.S       | 2 +-
 arch/powerpc/kernel/head_8xx.S       | 2 +-
 arch/powerpc/kernel/head_booke.h     | 4 ++--
 arch/powerpc/kernel/head_fsl_booke.S | 4 ++--
 arch/powerpc/kernel/irq.c            | 2 +-
 arch/powerpc/kernel/misc_32.S        | 4 ++--
 arch/powerpc/kernel/process.c        | 8 ++++----
 arch/powerpc/kernel/setup-common.c   | 2 +-
 arch/powerpc/kernel/smp.c            | 4 +++-
 18 files changed, 32 insertions(+), 30 deletions(-)

diff --git a/arch/powerpc/include/asm/irq.h b/arch/powerpc/include/asm/irq.h
index ee39ce56b2a2..2efbae8d93be 100644
--- a/arch/powerpc/include/asm/irq.h
+++ b/arch/powerpc/include/asm/irq.h
@@ -63,8 +63,8 @@ extern struct thread_info *hardirq_ctx[NR_CPUS];
 extern struct thread_info *softirq_ctx[NR_CPUS];
 
 extern void irq_ctx_init(void);
-extern void call_do_softirq(struct thread_info *tp);
-extern void call_do_irq(struct pt_regs *regs, struct thread_info *tp);
+void call_do_softirq(void *sp);
+void call_do_irq(struct pt_regs *regs, void *sp);
 extern void do_IRQ(struct pt_regs *regs);
 extern void __init init_IRQ(void);
 extern void __do_irq(struct pt_regs *regs);
diff --git a/arch/powerpc/include/asm/livepatch.h b/arch/powerpc/include/asm/livepatch.h
index 47a03b9b528b..7cb514865a28 100644
--- a/arch/powerpc/include/asm/livepatch.h
+++ b/arch/powerpc/include/asm/livepatch.h
@@ -43,13 +43,13 @@ static inline unsigned long klp_get_ftrace_location(unsigned long faddr)
 	return ftrace_location_range(faddr, faddr + 16);
 }
 
-static inline void klp_init_thread_info(struct thread_info *ti)
+static inline void klp_init_thread_info(struct task_struct *p)
 {
 	/* + 1 to account for STACK_END_MAGIC */
-	ti->livepatch_sp = (unsigned long *)(ti + 1) + 1;
+	task_thread_info(p)->livepatch_sp = end_of_stack(p) + 1;
 }
 #else
-static void klp_init_thread_info(struct thread_info *ti) { }
+static inline void klp_init_thread_info(struct task_struct *p) { }
 #endif /* CONFIG_LIVEPATCH */
 
 #endif /* _ASM_POWERPC_LIVEPATCH_H */
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 692f7383d461..15acb282a876 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -40,7 +40,7 @@
 
 #ifndef __ASSEMBLY__
 #include <linux/types.h>
-#include <asm/thread_info.h>
+#include <linux/thread_info.h>
 #include <asm/ptrace.h>
 #include <asm/hw_breakpoint.h>
 
@@ -326,7 +326,7 @@ struct thread_struct {
 
 #define INIT_SP		(sizeof(init_stack) + (unsigned long) &init_stack)
 #define INIT_SP_LIMIT \
-	(_ALIGN_UP(sizeof(init_thread_info), 16) + (unsigned long) &init_stack)
+	(_ALIGN_UP(sizeof(struct thread_info), 16) + (unsigned long)&init_stack)
 
 #ifdef CONFIG_SPE
 #define SPEFSCR_INIT \
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index 1c98ef1f2d5b..581e61db2dcf 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -1062,7 +1062,7 @@
  *	- SPRG9 debug exception scratch
  *
  * All 32-bit:
- *	- SPRG3 current thread_info pointer
+ *	- SPRG3 current thread_struct physical addr pointer
  *        (virtual on BookE, physical on others)
  *
  * 32-bit classic:
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 9ffc72ded73a..b2b52e002a76 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -90,10 +90,10 @@ int main(void)
 	DEFINE(SIGSEGV, SIGSEGV);
 	DEFINE(NMI_MASK, NMI_MASK);
 #else
-	OFFSET(THREAD_INFO, task_struct, stack);
 	DEFINE(THREAD_INFO_GAP, _ALIGN_UP(sizeof(struct thread_info), 16));
 	OFFSET(KSP_LIMIT, thread_struct, ksp_limit);
 #endif /* CONFIG_PPC64 */
+	OFFSET(TASK_STACK, task_struct, stack);
 
 #ifdef CONFIG_LIVEPATCH
 	OFFSET(TI_livepatch_sp, thread_info, livepatch_sp);
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 0768dfd8a64e..3f83e71ae43f 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -1166,7 +1166,7 @@ ret_from_debug_exc:
 	mfspr	r9,SPRN_SPRG_THREAD
 	lwz	r10,SAVED_KSP_LIMIT(r1)
 	stw	r10,KSP_LIMIT(r9)
-	lwz	r9,THREAD_INFO-THREAD(r9)
+	lwz	r9,TASK_STACK-THREAD(r9)
 	CURRENT_THREAD_INFO(r10, r1)
 	lwz	r10,TI_PREEMPT(r10)
 	stw	r10,TI_PREEMPT(r9)
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 435927f549c4..01d0706d873f 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -695,7 +695,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
 2:
 #endif /* CONFIG_PPC_BOOK3S_64 */
 
-	CURRENT_THREAD_INFO(r7, r8)  /* base of new stack */
+	clrrdi	r7, r8, THREAD_SHIFT	/* base of new stack */
 	/* Note: this uses SWITCH_FRAME_SIZE rather than INT_FRAME_SIZE
 	   because we don't need to leave the 288-byte ABI gap at the
 	   top of the kernel stack. */
diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index 05b08db3901d..8282d25948ae 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -261,7 +261,7 @@ __secondary_hold_acknowledge:
 	tophys(r11,r1);			/* use tophys(r1) if kernel */ \
 	beq	1f;		\
 	mfspr	r11,SPRN_SPRG_THREAD;	\
-	lwz	r11,THREAD_INFO-THREAD(r11);	\
+	lwz	r11,TASK_STACK-THREAD(r11);	\
 	addi	r11,r11,THREAD_SIZE;	\
 	tophys(r11,r11);	\
 1:	subi	r11,r11,INT_FRAME_SIZE	/* alloc exc. frame */
@@ -845,7 +845,7 @@ __secondary_start:
 	bl	init_idle_6xx
 #endif /* CONFIG_PPC_BOOK3S_32 */
 
-	/* get current_thread_info and current */
+	/* get current's stack and current */
 	lis	r1,secondary_ti@ha
 	tophys(r1,r1)
 	lwz	r1,secondary_ti@l(r1)
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index b19d78410511..3088c9f29f5e 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -115,7 +115,7 @@ _ENTRY(saved_ksp_limit)
 	andi.	r11,r11,MSR_PR;						     \
 	beq	1f;							     \
 	mfspr	r1,SPRN_SPRG_THREAD;	/* if from user, start at top of   */\
-	lwz	r1,THREAD_INFO-THREAD(r1); /* this thread's kernel stack   */\
+	lwz	r1,TASK_STACK-THREAD(r1); /* this thread's kernel stack   */\
 	addi	r1,r1,THREAD_SIZE;					     \
 1:	subi	r1,r1,INT_FRAME_SIZE;	/* Allocate an exception frame     */\
 	tophys(r11,r1);							     \
@@ -158,7 +158,7 @@ _ENTRY(saved_ksp_limit)
 	beq	1f;							     \
 	/* COMING FROM USER MODE */					     \
 	mfspr	r11,SPRN_SPRG_THREAD;	/* if from user, start at top of   */\
-	lwz	r11,THREAD_INFO-THREAD(r11); /* this thread's kernel stack */\
+	lwz	r11,TASK_STACK-THREAD(r11); /* this thread's kernel stack */\
 1:	addi	r11,r11,THREAD_SIZE-INT_FRAME_SIZE; /* Alloc an excpt frm  */\
 	tophys(r11,r11);						     \
 	stw	r10,_CCR(r11);          /* save various registers	   */\
diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
index bf23c19c92d6..4e8c8bf50413 100644
--- a/arch/powerpc/kernel/head_44x.S
+++ b/arch/powerpc/kernel/head_44x.S
@@ -1019,7 +1019,7 @@ _GLOBAL(start_secondary_47x)
 
 	/* Now we can get our task struct and real stack pointer */
 
-	/* Get current_thread_info and current */
+	/* Get current's stack and current */
 	lis	r1,secondary_ti@ha
 	lwz	r1,secondary_ti@l(r1)
 	lwz	r2,TI_TASK(r1)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 57deb1e9ffea..5f5f89e87e3a 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -142,7 +142,7 @@ instruction_counter:
 	tophys(r11,r1);			/* use tophys(r1) if kernel */ \
 	beq	1f;		\
 	mfspr	r11,SPRN_SPRG_THREAD;	\
-	lwz	r11,THREAD_INFO-THREAD(r11);	\
+	lwz	r11,TASK_STACK-THREAD(r11);	\
 	addi	r11,r11,THREAD_SIZE;	\
 	tophys(r11,r11);	\
 1:	subi	r11,r11,INT_FRAME_SIZE	/* alloc exc. frame */
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index 306e26c073a0..69e80e6d0d16 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -55,7 +55,7 @@ END_BTB_FLUSH_SECTION
 	beq	1f;							     \
 	BOOKE_CLEAR_BTB(r11)						\
 	/* if from user, start at top of this thread's kernel stack */       \
-	lwz	r11, THREAD_INFO-THREAD(r10);				     \
+	lwz	r11, TASK_STACK - THREAD(r10);				     \
 	ALLOC_STACK_FRAME(r11, THREAD_SIZE);				     \
 1 :	subi	r11, r11, INT_FRAME_SIZE; /* Allocate exception frame */     \
 	stw	r13, _CCR(r11);		/* save various registers */	     \
@@ -142,7 +142,7 @@ END_BTB_FLUSH_SECTION
 	BOOKE_CLEAR_BTB(r10)						\
 	andi.	r11,r11,MSR_PR;						     \
 	mfspr	r11,SPRN_SPRG_THREAD;	/* if from user, start at top of   */\
-	lwz	r11,THREAD_INFO-THREAD(r11); /* this thread's kernel stack */\
+	lwz	r11, TASK_STACK - THREAD(r11); /* this thread's kernel stack */\
 	addi	r11,r11,EXC_LVL_FRAME_OVERHEAD;	/* allocate stack frame    */\
 	beq	1f;							     \
 	/* COMING FROM USER MODE */					     \
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 2c21e8642a00..6301bb24889a 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -719,7 +719,7 @@ finish_tlb_load:
 
 	/* Get the next_tlbcam_idx percpu var */
 #ifdef CONFIG_SMP
-	lwz	r12, THREAD_INFO-THREAD(r12)
+	lwz	r12, TASK_STACK-THREAD(r12)
 	lwz	r15, TI_CPU(r12)
 	lis     r14, __per_cpu_offset@h
 	ori     r14, r14, __per_cpu_offset@l
@@ -1091,7 +1091,7 @@ __secondary_start:
 	mr	r4,r24		/* Why? */
 	bl	call_setup_cpu
 
-	/* get current_thread_info and current */
+	/* get current's stack and current */
 	lis	r1,secondary_ti@ha
 	lwz	r1,secondary_ti@l(r1)
 	lwz	r2,TI_TASK(r1)
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 4a44bc395fbc..2b152c36d7f4 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -663,7 +663,7 @@ void do_IRQ(struct pt_regs *regs)
 	struct thread_info *curtp, *irqtp, *sirqtp;
 
 	/* Switch to the irq stack to handle this */
-	curtp = current_thread_info();
+	curtp = (void *)(current_stack_pointer() & ~(THREAD_SIZE - 1));
 	irqtp = hardirq_ctx[raw_smp_processor_id()];
 	sirqtp = softirq_ctx[raw_smp_processor_id()];
 
diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index 02b8cdd73792..b37b50fde828 100644
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -60,7 +60,7 @@ _GLOBAL(call_do_softirq)
 	blr
 
 /*
- * void call_do_irq(struct pt_regs *regs, struct thread_info *irqtp);
+ * void call_do_irq(struct pt_regs *regs, void *sp);
  */
 _GLOBAL(call_do_irq)
 	mflr	r0
@@ -603,7 +603,7 @@ EXPORT_SYMBOL(__bswapdi2)
 #ifdef CONFIG_SMP
 _GLOBAL(start_secondary_resume)
 	/* Reset stack */
-	CURRENT_THREAD_INFO(r1, r1)
+	rlwinm	r1, r1, 0, 0, 31 - THREAD_SHIFT
 	addi	r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
 	li	r3,0
 	stw	r3,0(r1)		/* Zero the stack frame pointer	*/
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index ce393df243aa..1fc6b1d7c5fa 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1231,8 +1231,8 @@ struct task_struct *__switch_to(struct task_struct *prev,
 		batch->active = 1;
 	}
 
-	if (current_thread_info()->task->thread.regs) {
-		restore_math(current_thread_info()->task->thread.regs);
+	if (current->thread.regs) {
+		restore_math(current->thread.regs);
 
 		/*
 		 * The copy-paste buffer can only store into foreign real
@@ -1242,7 +1242,7 @@ struct task_struct *__switch_to(struct task_struct *prev,
 		 * mappings, we must issue a cp_abort to clear any state and
 		 * prevent snooping, corruption or a covert channel.
 		 */
-		if (current_thread_info()->task->thread.used_vas)
+		if (current->thread.used_vas)
 			asm volatile(PPC_CP_ABORT);
 	}
 #endif /* CONFIG_PPC_BOOK3S_64 */
@@ -1634,7 +1634,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 	unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
 	struct thread_info *ti = task_thread_info(p);
 
-	klp_init_thread_info(ti);
+	klp_init_thread_info(p);
 
 	/* Copy registers */
 	sp -= sizeof(struct pt_regs);
diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index ca00fbb97cf8..3d0dab1647fe 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -938,7 +938,7 @@ void __init setup_arch(char **cmdline_p)
 	/* Reserve large chunks of memory for use by CMA for KVM. */
 	kvm_cma_reserve();
 
-	klp_init_thread_info(&init_thread_info);
+	klp_init_thread_info(&init_task);
 
 	init_mm.start_code = (unsigned long)_stext;
 	init_mm.end_code = (unsigned long) _etext;
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 3f15edf25a0d..1d3e7cb6704d 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -20,6 +20,7 @@
 #include <linux/kernel.h>
 #include <linux/export.h>
 #include <linux/sched/mm.h>
+#include <linux/sched/task_stack.h>
 #include <linux/sched/topology.h>
 #include <linux/smp.h>
 #include <linux/interrupt.h>
@@ -1017,7 +1018,8 @@ static void cpu_idle_thread_init(unsigned int cpu, struct task_struct *idle)
 
 #ifdef CONFIG_PPC64
 	paca_ptrs[cpu]->__current = idle;
-	paca_ptrs[cpu]->kstack = (unsigned long)ti + THREAD_SIZE - STACK_FRAME_OVERHEAD;
+	paca_ptrs[cpu]->kstack = (unsigned long)task_stack_page(idle) +
+				 THREAD_SIZE - STACK_FRAME_OVERHEAD;
 #endif
 	ti->cpu = cpu;
 	secondary_ti = current_set[cpu] = ti;
-- 
2.13.3


^ permalink raw reply	[flat|nested] 16+ messages in thread

* [PATCH v13 05/10] powerpc: Activate CONFIG_THREAD_INFO_IN_TASK
  2019-01-12  9:55 [PATCH v13 00/10] powerpc: Switch to CONFIG_THREAD_INFO_IN_TASK Christophe Leroy
                   ` (3 preceding siblings ...)
  2019-01-12  9:55 ` [PATCH v13 04/10] powerpc: Prepare for moving thread_info into task_struct Christophe Leroy
@ 2019-01-12  9:55 ` Christophe Leroy
  2019-01-12  9:55 ` [PATCH v13 06/10] powerpc: regain entire stack space Christophe Leroy
                   ` (6 subsequent siblings)
  11 siblings, 0 replies; 16+ messages in thread
From: Christophe Leroy @ 2019-01-12  9:55 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
	Nicholas Piggin, Mike Rapoport
  Cc: linuxppc-dev, linux-kernel

This patch activates CONFIG_THREAD_INFO_IN_TASK which
moves the thread_info into task_struct.

Moving thread_info into task_struct has the following advantages:
- It protects thread_info from corruption in the case of stack
overflows.
- Its address is harder to determine if stack addresses are
leaked, making a number of attacks more difficult.

This has the following consequences:
- thread_info is now located at the beginning of task_struct.
- The 'cpu' field is now in task_struct, and only exists when
CONFIG_SMP is active.
- thread_info doesn't have anymore the 'task' field.

This patch:
- Removes all recopy of thread_info struct when the stack changes.
- Changes the CURRENT_THREAD_INFO() macro to point to current.
- Selects CONFIG_THREAD_INFO_IN_TASK.
- Modifies raw_smp_processor_id() to get ->cpu from current without
including linux/sched.h to avoid circular inclusion and without
including asm/asm-offsets.h to avoid symbol names duplication
between ASM constants and C constants.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/Kconfig                   |  1 +
 arch/powerpc/Makefile                  |  7 +++
 arch/powerpc/include/asm/irq.h         |  4 --
 arch/powerpc/include/asm/ptrace.h      |  2 +-
 arch/powerpc/include/asm/smp.h         | 17 +++++++-
 arch/powerpc/include/asm/thread_info.h | 17 +-------
 arch/powerpc/kernel/asm-offsets.c      |  7 ++-
 arch/powerpc/kernel/entry_32.S         |  9 ++--
 arch/powerpc/kernel/exceptions-64e.S   | 11 -----
 arch/powerpc/kernel/head_32.S          |  6 +--
 arch/powerpc/kernel/head_44x.S         |  4 +-
 arch/powerpc/kernel/head_64.S          |  1 +
 arch/powerpc/kernel/head_booke.h       |  8 +---
 arch/powerpc/kernel/head_fsl_booke.S   |  7 ++-
 arch/powerpc/kernel/irq.c              | 79 +---------------------------------
 arch/powerpc/kernel/kgdb.c             | 28 ------------
 arch/powerpc/kernel/machine_kexec_64.c |  6 +--
 arch/powerpc/kernel/setup_64.c         | 21 ---------
 arch/powerpc/kernel/smp.c              |  2 +-
 arch/powerpc/net/bpf_jit32.h           |  5 +--
 20 files changed, 52 insertions(+), 190 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 2890d36eb531..0a26e0075ce5 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -241,6 +241,7 @@ config PPC
 	select RTC_LIB
 	select SPARSE_IRQ
 	select SYSCTL_EXCEPTION_TRACE
+	select THREAD_INFO_IN_TASK
 	select VIRT_TO_BUS			if !PPC64
 	#
 	# Please keep this list sorted alphabetically.
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 488c9edffa58..326e8ba6e314 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -427,6 +427,13 @@ else
 endif
 endif
 
+ifdef CONFIG_SMP
+prepare: task_cpu_prepare
+
+task_cpu_prepare: prepare0
+	$(eval KBUILD_CFLAGS += -D_TASK_CPU=$(shell awk '{if ($$2 == "TI_CPU") print $$3;}' include/generated/asm-offsets.h))
+endif
+
 # Check toolchain versions:
 # - gcc-4.6 is the minimum kernel-wide version so nothing required.
 checkbin:
diff --git a/arch/powerpc/include/asm/irq.h b/arch/powerpc/include/asm/irq.h
index 2efbae8d93be..28a7ace0a1b9 100644
--- a/arch/powerpc/include/asm/irq.h
+++ b/arch/powerpc/include/asm/irq.h
@@ -51,9 +51,6 @@ struct pt_regs;
 extern struct thread_info *critirq_ctx[NR_CPUS];
 extern struct thread_info *dbgirq_ctx[NR_CPUS];
 extern struct thread_info *mcheckirq_ctx[NR_CPUS];
-extern void exc_lvl_ctx_init(void);
-#else
-#define exc_lvl_ctx_init()
 #endif
 
 /*
@@ -62,7 +59,6 @@ extern void exc_lvl_ctx_init(void);
 extern struct thread_info *hardirq_ctx[NR_CPUS];
 extern struct thread_info *softirq_ctx[NR_CPUS];
 
-extern void irq_ctx_init(void);
 void call_do_softirq(void *sp);
 void call_do_irq(struct pt_regs *regs, void *sp);
 extern void do_IRQ(struct pt_regs *regs);
diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index 0b8a735b6d85..64271e562fed 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -157,7 +157,7 @@ extern int ptrace_put_reg(struct task_struct *task, int regno,
 			  unsigned long data);
 
 #define current_pt_regs() \
-	((struct pt_regs *)((unsigned long)current_thread_info() + THREAD_SIZE) - 1)
+	((struct pt_regs *)((unsigned long)task_stack_page(current) + THREAD_SIZE) - 1)
 /*
  * We use the least-significant bit of the trap field to indicate
  * whether we have saved the full set of registers, or only a
diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h
index 41695745032c..0de717e16dd6 100644
--- a/arch/powerpc/include/asm/smp.h
+++ b/arch/powerpc/include/asm/smp.h
@@ -83,7 +83,22 @@ int is_cpu_dead(unsigned int cpu);
 /* 32-bit */
 extern int smp_hw_index[];
 
-#define raw_smp_processor_id()	(current_thread_info()->cpu)
+/*
+ * This is particularly ugly: it appears we can't actually get the definition
+ * of task_struct here, but we need access to the CPU this task is running on.
+ * Instead of using task_struct we're using _TASK_CPU which is extracted from
+ * asm-offsets.h by kbuild to get the current processor ID.
+ *
+ * This also needs to be safeguarded when building asm-offsets.s because at
+ * that time _TASK_CPU is not defined yet. It could have been guarded by
+ * _TASK_CPU itself, but we want the build to fail if _TASK_CPU is missing
+ * when building something else than asm-offsets.s
+ */
+#ifdef GENERATING_ASM_OFFSETS
+#define raw_smp_processor_id()		(0)
+#else
+#define raw_smp_processor_id()		(*(unsigned int *)((void *)current + _TASK_CPU))
+#endif
 #define hard_smp_processor_id() 	(smp_hw_index[smp_processor_id()])
 
 static inline int get_hard_smp_processor_id(int cpu)
diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index 544cac0474cb..d91523c2c7d8 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -18,9 +18,9 @@
 #define THREAD_SIZE		(1 << THREAD_SHIFT)
 
 #ifdef CONFIG_PPC64
-#define CURRENT_THREAD_INFO(dest, sp)	stringify_in_c(clrrdi dest, sp, THREAD_SHIFT)
+#define CURRENT_THREAD_INFO(dest, sp)	stringify_in_c(ld dest, PACACURRENT(r13))
 #else
-#define CURRENT_THREAD_INFO(dest, sp)	stringify_in_c(rlwinm dest, sp, 0, 0, 31-THREAD_SHIFT)
+#define CURRENT_THREAD_INFO(dest, sp)	stringify_in_c(mr dest, r2)
 #endif
 
 #ifndef __ASSEMBLY__
@@ -34,8 +34,6 @@
  * low level task data.
  */
 struct thread_info {
-	struct task_struct *task;		/* main task structure */
-	int		cpu;			/* cpu we're on */
 	int		preempt_count;		/* 0 => preemptable,
 						   <0 => BUG */
 	unsigned long	local_flags;		/* private flags for thread */
@@ -58,8 +56,6 @@ struct thread_info {
  */
 #define INIT_THREAD_INFO(tsk)			\
 {						\
-	.task =		&tsk,			\
-	.cpu =		0,			\
 	.preempt_count = INIT_PREEMPT_COUNT,	\
 	.flags =	0,			\
 }
@@ -67,15 +63,6 @@ struct thread_info {
 #define THREAD_SIZE_ORDER	(THREAD_SHIFT - PAGE_SHIFT)
 
 /* how to get the thread information struct from C */
-static inline struct thread_info *current_thread_info(void)
-{
-	unsigned long val;
-
-	asm (CURRENT_THREAD_INFO(%0,1) : "=r" (val));
-
-	return (struct thread_info *)val;
-}
-
 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
 
 #ifdef CONFIG_PPC_BOOK3S_64
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index b2b52e002a76..1fb52206c106 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -13,6 +13,8 @@
  * 2 of the License, or (at your option) any later version.
  */
 
+#define GENERATING_ASM_OFFSETS	/* asm/smp.h */
+
 #include <linux/compat.h>
 #include <linux/signal.h>
 #include <linux/sched.h>
@@ -94,6 +96,9 @@ int main(void)
 	OFFSET(KSP_LIMIT, thread_struct, ksp_limit);
 #endif /* CONFIG_PPC64 */
 	OFFSET(TASK_STACK, task_struct, stack);
+#ifdef CONFIG_SMP
+	OFFSET(TI_CPU, task_struct, cpu);
+#endif
 
 #ifdef CONFIG_LIVEPATCH
 	OFFSET(TI_livepatch_sp, thread_info, livepatch_sp);
@@ -161,8 +166,6 @@ int main(void)
 	OFFSET(TI_FLAGS, thread_info, flags);
 	OFFSET(TI_LOCAL_FLAGS, thread_info, local_flags);
 	OFFSET(TI_PREEMPT, thread_info, preempt_count);
-	OFFSET(TI_TASK, thread_info, task);
-	OFFSET(TI_CPU, thread_info, cpu);
 
 #ifdef CONFIG_PPC64
 	OFFSET(DCACHEL1BLOCKSIZE, ppc64_caches, l1d.block_size);
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 3f83e71ae43f..1f5a76283bd4 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -1166,10 +1166,6 @@ ret_from_debug_exc:
 	mfspr	r9,SPRN_SPRG_THREAD
 	lwz	r10,SAVED_KSP_LIMIT(r1)
 	stw	r10,KSP_LIMIT(r9)
-	lwz	r9,TASK_STACK-THREAD(r9)
-	CURRENT_THREAD_INFO(r10, r1)
-	lwz	r10,TI_PREEMPT(r10)
-	stw	r10,TI_PREEMPT(r9)
 	RESTORE_xSRR(SRR0,SRR1);
 	RESTORE_xSRR(CSRR0,CSRR1);
 	RESTORE_MMU_REGS;
@@ -1292,10 +1288,13 @@ BEGIN_FTR_SECTION
 END_FTR_SECTION_IFSET(CPU_FTR_601)
 	lwz	r3,_TRAP(r1)
 	andi.	r0,r3,1
-	beq	4f
+	beq	5f
 	SAVE_NVGPRS(r1)
 	rlwinm	r3,r3,0,0,30
 	stw	r3,_TRAP(r1)
+5:	mfspr	r2,SPRN_SPRG_THREAD
+	addi	r2,r2,-THREAD
+	tovirt(r2,r2)			/* set back r2 to current */
 4:	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	unrecoverable_exception
 	/* shouldn't return */
diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S
index afb638778f44..20f14996281d 100644
--- a/arch/powerpc/kernel/exceptions-64e.S
+++ b/arch/powerpc/kernel/exceptions-64e.S
@@ -77,17 +77,6 @@ special_reg_save:
 	andi.	r3,r3,MSR_PR
 	bnelr
 
-	/* Copy info into temporary exception thread info */
-	ld	r11,PACAKSAVE(r13)
-	CURRENT_THREAD_INFO(r11, r11)
-	CURRENT_THREAD_INFO(r12, r1)
-	ld	r10,TI_FLAGS(r11)
-	std	r10,TI_FLAGS(r12)
-	ld	r10,TI_PREEMPT(r11)
-	std	r10,TI_PREEMPT(r12)
-	ld	r10,TI_TASK(r11)
-	std	r10,TI_TASK(r12)
-
 	/*
 	 * Advance to the next TLB exception frame for handler
 	 * types that don't do it automatically.
diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index 8282d25948ae..309a45779ad5 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -848,9 +848,9 @@ __secondary_start:
 	/* get current's stack and current */
 	lis	r1,secondary_ti@ha
 	tophys(r1,r1)
-	lwz	r1,secondary_ti@l(r1)
-	tophys(r2,r1)
-	lwz	r2,TI_TASK(r2)
+	lwz	r2,secondary_ti@l(r1)
+	tophys(r1,r2)
+	lwz	r1,TASK_STACK(r1)
 
 	/* stack */
 	addi	r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
index 4e8c8bf50413..f94a93b6c2f2 100644
--- a/arch/powerpc/kernel/head_44x.S
+++ b/arch/powerpc/kernel/head_44x.S
@@ -1021,8 +1021,8 @@ _GLOBAL(start_secondary_47x)
 
 	/* Get current's stack and current */
 	lis	r1,secondary_ti@ha
-	lwz	r1,secondary_ti@l(r1)
-	lwz	r2,TI_TASK(r1)
+	lwz	r2,secondary_ti@l(r1)
+	lwz	r1,TASK_STACK(r2)
 
 	/* Current stack pointer */
 	addi	r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index 4898e9491a1c..c6a9bf7b34bf 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -805,6 +805,7 @@ __secondary_start:
 	LOAD_REG_ADDR(r3, current_set)
 	sldi	r28,r24,3		/* get current_set[cpu#]	 */
 	ldx	r14,r3,r28
+	ld	r14,TASK_STACK(r14)
 	addi	r14,r14,THREAD_SIZE-STACK_FRAME_OVERHEAD
 	std	r14,PACAKSAVE(r13)
 
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index 69e80e6d0d16..1b22a8dea399 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -155,13 +155,7 @@ END_BTB_FLUSH_SECTION
 	stw	r10,GPR11(r11);						     \
 	b	2f;							     \
 	/* COMING FROM PRIV MODE */					     \
-1:	lwz	r9,TI_FLAGS-EXC_LVL_FRAME_OVERHEAD(r11);		     \
-	lwz	r10,TI_PREEMPT-EXC_LVL_FRAME_OVERHEAD(r11);		     \
-	stw	r9,TI_FLAGS-EXC_LVL_FRAME_OVERHEAD(r8);			     \
-	stw	r10,TI_PREEMPT-EXC_LVL_FRAME_OVERHEAD(r8);		     \
-	lwz	r9,TI_TASK-EXC_LVL_FRAME_OVERHEAD(r11);			     \
-	stw	r9,TI_TASK-EXC_LVL_FRAME_OVERHEAD(r8);			     \
-	mr	r11,r8;							     \
+1:	mr	r11, r8;							     \
 2:	mfspr	r8,SPRN_SPRG_RSCRATCH_##exc_level;			     \
 	stw	r12,GPR12(r11);		/* save various registers	   */\
 	mflr	r10;							     \
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 6301bb24889a..11f38adbe020 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -719,8 +719,7 @@ finish_tlb_load:
 
 	/* Get the next_tlbcam_idx percpu var */
 #ifdef CONFIG_SMP
-	lwz	r12, TASK_STACK-THREAD(r12)
-	lwz	r15, TI_CPU(r12)
+	lwz	r15, TI_CPU-THREAD(r12)
 	lis     r14, __per_cpu_offset@h
 	ori     r14, r14, __per_cpu_offset@l
 	rlwinm  r15, r15, 2, 0, 29
@@ -1093,8 +1092,8 @@ __secondary_start:
 
 	/* get current's stack and current */
 	lis	r1,secondary_ti@ha
-	lwz	r1,secondary_ti@l(r1)
-	lwz	r2,TI_TASK(r1)
+	lwz	r2,secondary_ti@l(r1)
+	lwz	r1,TASK_STACK(r2)
 
 	/* stack */
 	addi	r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 2b152c36d7f4..acaeae1f11f5 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -673,24 +673,9 @@ void do_IRQ(struct pt_regs *regs)
 		set_irq_regs(old_regs);
 		return;
 	}
-
-	/* Prepare the thread_info in the irq stack */
-	irqtp->task = curtp->task;
-	irqtp->flags = 0;
-
-	/* Copy the preempt_count so that the [soft]irq checks work. */
-	irqtp->preempt_count = curtp->preempt_count;
-
 	/* Switch stack and call */
 	call_do_irq(regs, irqtp);
 
-	/* Restore stack limit */
-	irqtp->task = NULL;
-
-	/* Copy back updates to the thread_info */
-	if (irqtp->flags)
-		set_bits(irqtp->flags, &curtp->flags);
-
 	set_irq_regs(old_regs);
 }
 
@@ -698,85 +683,23 @@ void __init init_IRQ(void)
 {
 	if (ppc_md.init_IRQ)
 		ppc_md.init_IRQ();
-
-	exc_lvl_ctx_init();
-
-	irq_ctx_init();
 }
 
 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
-
-void exc_lvl_ctx_init(void)
-{
-	struct thread_info *tp;
-	int i, cpu_nr;
-
-	for_each_possible_cpu(i) {
-#ifdef CONFIG_PPC64
-		cpu_nr = i;
-#else
-#ifdef CONFIG_SMP
-		cpu_nr = get_hard_smp_processor_id(i);
-#else
-		cpu_nr = 0;
-#endif
-#endif
-
-		tp = critirq_ctx[cpu_nr];
-		tp->cpu = cpu_nr;
-		tp->preempt_count = 0;
-
-#ifdef CONFIG_BOOKE
-		tp = dbgirq_ctx[cpu_nr];
-		tp->cpu = cpu_nr;
-		tp->preempt_count = 0;
-
-		tp = mcheckirq_ctx[cpu_nr];
-		tp->cpu = cpu_nr;
-		tp->preempt_count = HARDIRQ_OFFSET;
-#endif
-	}
-}
 #endif
 
 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 
-void irq_ctx_init(void)
-{
-	struct thread_info *tp;
-	int i;
-
-	for_each_possible_cpu(i) {
-		tp = softirq_ctx[i];
-		tp->cpu = i;
-		klp_init_thread_info(tp);
-
-		tp = hardirq_ctx[i];
-		tp->cpu = i;
-		klp_init_thread_info(tp);
-	}
-}
-
 void do_softirq_own_stack(void)
 {
-	struct thread_info *curtp, *irqtp;
+	struct thread_info *irqtp;
 
-	curtp = current_thread_info();
 	irqtp = softirq_ctx[smp_processor_id()];
-	irqtp->task = curtp->task;
-	irqtp->flags = 0;
 	call_do_softirq(irqtp);
-	irqtp->task = NULL;
-
-	/* Set any flag that may have been set on the
-	 * alternate stack
-	 */
-	if (irqtp->flags)
-		set_bits(irqtp->flags, &curtp->flags);
 }
 
 irq_hw_number_t virq_to_hw(unsigned int virq)
diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c
index e1865565f0ae..7dd55eb1259d 100644
--- a/arch/powerpc/kernel/kgdb.c
+++ b/arch/powerpc/kernel/kgdb.c
@@ -151,41 +151,13 @@ static int kgdb_handle_breakpoint(struct pt_regs *regs)
 	return 1;
 }
 
-static DEFINE_PER_CPU(struct thread_info, kgdb_thread_info);
 static int kgdb_singlestep(struct pt_regs *regs)
 {
-	struct thread_info *thread_info, *exception_thread_info;
-	struct thread_info *backup_current_thread_info =
-		this_cpu_ptr(&kgdb_thread_info);
-
 	if (user_mode(regs))
 		return 0;
 
-	/*
-	 * On Book E and perhaps other processors, singlestep is handled on
-	 * the critical exception stack.  This causes current_thread_info()
-	 * to fail, since it it locates the thread_info by masking off
-	 * the low bits of the current stack pointer.  We work around
-	 * this issue by copying the thread_info from the kernel stack
-	 * before calling kgdb_handle_exception, and copying it back
-	 * afterwards.  On most processors the copy is avoided since
-	 * exception_thread_info == thread_info.
-	 */
-	thread_info = (struct thread_info *)(regs->gpr[1] & ~(THREAD_SIZE-1));
-	exception_thread_info = current_thread_info();
-
-	if (thread_info != exception_thread_info) {
-		/* Save the original current_thread_info. */
-		memcpy(backup_current_thread_info, exception_thread_info, sizeof *thread_info);
-		memcpy(exception_thread_info, thread_info, sizeof *thread_info);
-	}
-
 	kgdb_handle_exception(0, SIGTRAP, 0, regs);
 
-	if (thread_info != exception_thread_info)
-		/* Restore current_thread_info lastly. */
-		memcpy(exception_thread_info, backup_current_thread_info, sizeof *thread_info);
-
 	return 1;
 }
 
diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c
index a0f6f45005bd..75692c327ba0 100644
--- a/arch/powerpc/kernel/machine_kexec_64.c
+++ b/arch/powerpc/kernel/machine_kexec_64.c
@@ -317,10 +317,8 @@ void default_machine_kexec(struct kimage *image)
 	 * We setup preempt_count to avoid using VMX in memcpy.
 	 * XXX: the task struct will likely be invalid once we do the copy!
 	 */
-	kexec_stack.thread_info.task = current_thread_info()->task;
-	kexec_stack.thread_info.flags = 0;
-	kexec_stack.thread_info.preempt_count = HARDIRQ_OFFSET;
-	kexec_stack.thread_info.cpu = current_thread_info()->cpu;
+	current_thread_info()->flags = 0;
+	current_thread_info()->preempt_count = HARDIRQ_OFFSET;
 
 	/* We need a static PACA, too; copy this CPU's PACA over and switch to
 	 * it. Also poison per_cpu_offset and NULL lppaca to catch anyone using
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 080dd515d587..0912948a8ea6 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -690,24 +690,6 @@ void __init exc_lvl_early_init(void)
 #endif
 
 /*
- * Emergency stacks are used for a range of things, from asynchronous
- * NMIs (system reset, machine check) to synchronous, process context.
- * We set preempt_count to zero, even though that isn't necessarily correct. To
- * get the right value we'd need to copy it from the previous thread_info, but
- * doing that might fault causing more problems.
- * TODO: what to do with accounting?
- */
-static void emerg_stack_init_thread_info(struct thread_info *ti, int cpu)
-{
-	ti->task = NULL;
-	ti->cpu = cpu;
-	ti->preempt_count = 0;
-	ti->local_flags = 0;
-	ti->flags = 0;
-	klp_init_thread_info(ti);
-}
-
-/*
  * Stack space used when we detect a bad kernel stack pointer, and
  * early in SMP boots before relocation is enabled. Exclusive emergency
  * stack for machine checks.
@@ -737,18 +719,15 @@ void __init emergency_stack_init(void)
 		struct thread_info *ti;
 
 		ti = alloc_stack(limit, i);
-		emerg_stack_init_thread_info(ti, i);
 		paca_ptrs[i]->emergency_sp = (void *)ti + THREAD_SIZE;
 
 #ifdef CONFIG_PPC_BOOK3S_64
 		/* emergency stack for NMI exception handling. */
 		ti = alloc_stack(limit, i);
-		emerg_stack_init_thread_info(ti, i);
 		paca_ptrs[i]->nmi_emergency_sp = (void *)ti + THREAD_SIZE;
 
 		/* emergency stack for machine check exception handling. */
 		ti = alloc_stack(limit, i);
-		emerg_stack_init_thread_info(ti, i);
 		paca_ptrs[i]->mc_emergency_sp = (void *)ti + THREAD_SIZE;
 #endif
 	}
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 1d3e7cb6704d..aa4517686f90 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -1021,7 +1021,7 @@ static void cpu_idle_thread_init(unsigned int cpu, struct task_struct *idle)
 	paca_ptrs[cpu]->kstack = (unsigned long)task_stack_page(idle) +
 				 THREAD_SIZE - STACK_FRAME_OVERHEAD;
 #endif
-	ti->cpu = cpu;
+	idle->cpu = cpu;
 	secondary_ti = current_set[cpu] = ti;
 }
 
diff --git a/arch/powerpc/net/bpf_jit32.h b/arch/powerpc/net/bpf_jit32.h
index 6f4daacad296..dc50a8d4b3b9 100644
--- a/arch/powerpc/net/bpf_jit32.h
+++ b/arch/powerpc/net/bpf_jit32.h
@@ -106,9 +106,8 @@ DECLARE_LOAD_FUNC(sk_load_byte_msh);
 	} while (0)
 #else
 #define PPC_BPF_LOAD_CPU(r)     \
-	do { BUILD_BUG_ON(FIELD_SIZEOF(struct thread_info, cpu) != 4);		\
-		PPC_LHZ_OFFS(r, (1 & ~(THREAD_SIZE - 1)),			\
-				offsetof(struct thread_info, cpu));		\
+	do { BUILD_BUG_ON(FIELD_SIZEOF(struct task_struct, cpu) != 4);		\
+		PPC_LHZ_OFFS(r, 2, offsetof(struct task_struct, cpu));		\
 	} while(0)
 #endif
 #else
-- 
2.13.3


^ permalink raw reply	[flat|nested] 16+ messages in thread

* [PATCH v13 06/10] powerpc: regain entire stack space
  2019-01-12  9:55 [PATCH v13 00/10] powerpc: Switch to CONFIG_THREAD_INFO_IN_TASK Christophe Leroy
                   ` (4 preceding siblings ...)
  2019-01-12  9:55 ` [PATCH v13 05/10] powerpc: Activate CONFIG_THREAD_INFO_IN_TASK Christophe Leroy
@ 2019-01-12  9:55 ` Christophe Leroy
  2019-01-12  9:55 ` [PATCH v13 07/10] powerpc: 'current_set' is now a table of task_struct pointers Christophe Leroy
                   ` (5 subsequent siblings)
  11 siblings, 0 replies; 16+ messages in thread
From: Christophe Leroy @ 2019-01-12  9:55 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
	Nicholas Piggin, Mike Rapoport
  Cc: linuxppc-dev, linux-kernel

thread_info is not anymore in the stack, so the entire stack
can now be used.

There is also no risk anymore of corrupting task_cpu(p) with a
stack overflow so the patch removes the test.

When doing this, an explicit test for NULL stack pointer is
needed in validate_sp() as it is not anymore implicitely covered
by the sizeof(thread_info) gap.

In the meantime, with the previous patch all pointers to the stacks
are not anymore pointers to thread_info so this patch changes them
to void*

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/include/asm/irq.h       | 10 +++++-----
 arch/powerpc/include/asm/processor.h |  3 +--
 arch/powerpc/kernel/asm-offsets.c    |  1 -
 arch/powerpc/kernel/entry_32.S       | 14 ++++----------
 arch/powerpc/kernel/irq.c            | 19 +++++++++----------
 arch/powerpc/kernel/misc_32.S        |  6 ++----
 arch/powerpc/kernel/process.c        | 32 +++++++++++++-------------------
 arch/powerpc/kernel/setup_64.c       |  8 ++++----
 8 files changed, 38 insertions(+), 55 deletions(-)

diff --git a/arch/powerpc/include/asm/irq.h b/arch/powerpc/include/asm/irq.h
index 28a7ace0a1b9..c91a60cda4fa 100644
--- a/arch/powerpc/include/asm/irq.h
+++ b/arch/powerpc/include/asm/irq.h
@@ -48,16 +48,16 @@ struct pt_regs;
  * Per-cpu stacks for handling critical, debug and machine check
  * level interrupts.
  */
-extern struct thread_info *critirq_ctx[NR_CPUS];
-extern struct thread_info *dbgirq_ctx[NR_CPUS];
-extern struct thread_info *mcheckirq_ctx[NR_CPUS];
+extern void *critirq_ctx[NR_CPUS];
+extern void *dbgirq_ctx[NR_CPUS];
+extern void *mcheckirq_ctx[NR_CPUS];
 #endif
 
 /*
  * Per-cpu stacks for handling hard and soft interrupts.
  */
-extern struct thread_info *hardirq_ctx[NR_CPUS];
-extern struct thread_info *softirq_ctx[NR_CPUS];
+extern void *hardirq_ctx[NR_CPUS];
+extern void *softirq_ctx[NR_CPUS];
 
 void call_do_softirq(void *sp);
 void call_do_irq(struct pt_regs *regs, void *sp);
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 15acb282a876..8179b64871ed 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -325,8 +325,7 @@ struct thread_struct {
 #define ARCH_MIN_TASKALIGN 16
 
 #define INIT_SP		(sizeof(init_stack) + (unsigned long) &init_stack)
-#define INIT_SP_LIMIT \
-	(_ALIGN_UP(sizeof(struct thread_info), 16) + (unsigned long)&init_stack)
+#define INIT_SP_LIMIT	((unsigned long)&init_stack)
 
 #ifdef CONFIG_SPE
 #define SPEFSCR_INIT \
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 1fb52206c106..94ac190a0b16 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -92,7 +92,6 @@ int main(void)
 	DEFINE(SIGSEGV, SIGSEGV);
 	DEFINE(NMI_MASK, NMI_MASK);
 #else
-	DEFINE(THREAD_INFO_GAP, _ALIGN_UP(sizeof(struct thread_info), 16));
 	OFFSET(KSP_LIMIT, thread_struct, ksp_limit);
 #endif /* CONFIG_PPC64 */
 	OFFSET(TASK_STACK, task_struct, stack);
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 1f5a76283bd4..b547bd4168d8 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -97,14 +97,11 @@ crit_transfer_to_handler:
 	mfspr	r0,SPRN_SRR1
 	stw	r0,_SRR1(r11)
 
-	/* set the stack limit to the current stack
-	 * and set the limit to protect the thread_info
-	 * struct
-	 */
+	/* set the stack limit to the current stack */
 	mfspr	r8,SPRN_SPRG_THREAD
 	lwz	r0,KSP_LIMIT(r8)
 	stw	r0,SAVED_KSP_LIMIT(r11)
-	rlwimi	r0,r1,0,0,(31-THREAD_SHIFT)
+	rlwinm	r0,r1,0,0,(31 - THREAD_SHIFT)
 	stw	r0,KSP_LIMIT(r8)
 	/* fall through */
 #endif
@@ -121,14 +118,11 @@ crit_transfer_to_handler:
 	mfspr	r0,SPRN_SRR1
 	stw	r0,crit_srr1@l(0)
 
-	/* set the stack limit to the current stack
-	 * and set the limit to protect the thread_info
-	 * struct
-	 */
+	/* set the stack limit to the current stack */
 	mfspr	r8,SPRN_SPRG_THREAD
 	lwz	r0,KSP_LIMIT(r8)
 	stw	r0,saved_ksp_limit@l(0)
-	rlwimi	r0,r1,0,0,(31-THREAD_SHIFT)
+	rlwinm	r0,r1,0,0,(31 - THREAD_SHIFT)
 	stw	r0,KSP_LIMIT(r8)
 	/* fall through */
 #endif
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index acaeae1f11f5..1aef9316345f 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -618,9 +618,8 @@ static inline void check_stack_overflow(void)
 	sp = current_stack_pointer() & (THREAD_SIZE-1);
 
 	/* check for stack overflow: is there less than 2KB free? */
-	if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
-		pr_err("do_IRQ: stack overflow: %ld\n",
-			sp - sizeof(struct thread_info));
+	if (unlikely(sp < 2048)) {
+		pr_err("do_IRQ: stack overflow: %ld\n", sp);
 		dump_stack();
 	}
 #endif
@@ -660,7 +659,7 @@ void __do_irq(struct pt_regs *regs)
 void do_IRQ(struct pt_regs *regs)
 {
 	struct pt_regs *old_regs = set_irq_regs(regs);
-	struct thread_info *curtp, *irqtp, *sirqtp;
+	void *curtp, *irqtp, *sirqtp;
 
 	/* Switch to the irq stack to handle this */
 	curtp = (void *)(current_stack_pointer() & ~(THREAD_SIZE - 1));
@@ -686,17 +685,17 @@ void __init init_IRQ(void)
 }
 
 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
-struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
-struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
-struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
+void   *critirq_ctx[NR_CPUS] __read_mostly;
+void    *dbgirq_ctx[NR_CPUS] __read_mostly;
+void *mcheckirq_ctx[NR_CPUS] __read_mostly;
 #endif
 
-struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
-struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
+void *softirq_ctx[NR_CPUS] __read_mostly;
+void *hardirq_ctx[NR_CPUS] __read_mostly;
 
 void do_softirq_own_stack(void)
 {
-	struct thread_info *irqtp;
+	void *irqtp;
 
 	irqtp = softirq_ctx[smp_processor_id()];
 	call_do_softirq(irqtp);
diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index b37b50fde828..6f6127c3760c 100644
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -46,11 +46,10 @@ _GLOBAL(call_do_softirq)
 	mflr	r0
 	stw	r0,4(r1)
 	lwz	r10,THREAD+KSP_LIMIT(r2)
-	addi	r11,r3,THREAD_INFO_GAP
+	stw	r3, THREAD+KSP_LIMIT(r2)
 	stwu	r1,THREAD_SIZE-STACK_FRAME_OVERHEAD(r3)
 	mr	r1,r3
 	stw	r10,8(r1)
-	stw	r11,THREAD+KSP_LIMIT(r2)
 	bl	__do_softirq
 	lwz	r10,8(r1)
 	lwz	r1,0(r1)
@@ -66,11 +65,10 @@ _GLOBAL(call_do_irq)
 	mflr	r0
 	stw	r0,4(r1)
 	lwz	r10,THREAD+KSP_LIMIT(r2)
-	addi	r11,r4,THREAD_INFO_GAP
+	stw	r4, THREAD+KSP_LIMIT(r2)
 	stwu	r1,THREAD_SIZE-STACK_FRAME_OVERHEAD(r4)
 	mr	r1,r4
 	stw	r10,8(r1)
-	stw	r11,THREAD+KSP_LIMIT(r2)
 	bl	__do_irq
 	lwz	r10,8(r1)
 	lwz	r1,0(r1)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 1fc6b1d7c5fa..c300dc150b03 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1691,8 +1691,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 	sp -= STACK_FRAME_OVERHEAD;
 	p->thread.ksp = sp;
 #ifdef CONFIG_PPC32
-	p->thread.ksp_limit = (unsigned long)task_stack_page(p) +
-				_ALIGN_UP(sizeof(struct thread_info), 16);
+	p->thread.ksp_limit = (unsigned long)end_of_stack(p);
 #endif
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 	p->thread.ptrace_bps[0] = NULL;
@@ -1995,21 +1994,14 @@ static inline int valid_irq_stack(unsigned long sp, struct task_struct *p,
 	unsigned long stack_page;
 	unsigned long cpu = task_cpu(p);
 
-	/*
-	 * Avoid crashing if the stack has overflowed and corrupted
-	 * task_cpu(p), which is in the thread_info struct.
-	 */
-	if (cpu < NR_CPUS && cpu_possible(cpu)) {
-		stack_page = (unsigned long) hardirq_ctx[cpu];
-		if (sp >= stack_page + sizeof(struct thread_struct)
-		    && sp <= stack_page + THREAD_SIZE - nbytes)
-			return 1;
-
-		stack_page = (unsigned long) softirq_ctx[cpu];
-		if (sp >= stack_page + sizeof(struct thread_struct)
-		    && sp <= stack_page + THREAD_SIZE - nbytes)
-			return 1;
-	}
+	stack_page = (unsigned long)hardirq_ctx[cpu];
+	if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
+		return 1;
+
+	stack_page = (unsigned long)softirq_ctx[cpu];
+	if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
+		return 1;
+
 	return 0;
 }
 
@@ -2018,8 +2010,10 @@ int validate_sp(unsigned long sp, struct task_struct *p,
 {
 	unsigned long stack_page = (unsigned long)task_stack_page(p);
 
-	if (sp >= stack_page + sizeof(struct thread_struct)
-	    && sp <= stack_page + THREAD_SIZE - nbytes)
+	if (sp < THREAD_SIZE)
+		return 0;
+
+	if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
 		return 1;
 
 	return valid_irq_stack(sp, p, nbytes);
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 0912948a8ea6..2db1c5f7d141 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -716,19 +716,19 @@ void __init emergency_stack_init(void)
 	limit = min(ppc64_bolted_size(), ppc64_rma_size);
 
 	for_each_possible_cpu(i) {
-		struct thread_info *ti;
+		void *ti;
 
 		ti = alloc_stack(limit, i);
-		paca_ptrs[i]->emergency_sp = (void *)ti + THREAD_SIZE;
+		paca_ptrs[i]->emergency_sp = ti + THREAD_SIZE;
 
 #ifdef CONFIG_PPC_BOOK3S_64
 		/* emergency stack for NMI exception handling. */
 		ti = alloc_stack(limit, i);
-		paca_ptrs[i]->nmi_emergency_sp = (void *)ti + THREAD_SIZE;
+		paca_ptrs[i]->nmi_emergency_sp = ti + THREAD_SIZE;
 
 		/* emergency stack for machine check exception handling. */
 		ti = alloc_stack(limit, i);
-		paca_ptrs[i]->mc_emergency_sp = (void *)ti + THREAD_SIZE;
+		paca_ptrs[i]->mc_emergency_sp = ti + THREAD_SIZE;
 #endif
 	}
 }
-- 
2.13.3


^ permalink raw reply	[flat|nested] 16+ messages in thread

* [PATCH v13 07/10] powerpc: 'current_set' is now a table of task_struct pointers
  2019-01-12  9:55 [PATCH v13 00/10] powerpc: Switch to CONFIG_THREAD_INFO_IN_TASK Christophe Leroy
                   ` (5 preceding siblings ...)
  2019-01-12  9:55 ` [PATCH v13 06/10] powerpc: regain entire stack space Christophe Leroy
@ 2019-01-12  9:55 ` Christophe Leroy
  2019-01-12  9:55 ` [PATCH v13 08/10] powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU Christophe Leroy
                   ` (4 subsequent siblings)
  11 siblings, 0 replies; 16+ messages in thread
From: Christophe Leroy @ 2019-01-12  9:55 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
	Nicholas Piggin, Mike Rapoport
  Cc: linuxppc-dev, linux-kernel

The table of pointers 'current_set' has been used for retrieving
the stack and current. They used to be thread_info pointers as
they were pointing to the stack and current was taken from the
'task' field of the thread_info.

Now, the pointers of 'current_set' table are now both pointers
to task_struct and pointers to thread_info.

As they are used to get current, and the stack pointer is
retrieved from current's stack field, this patch changes
their type to task_struct, and renames secondary_ti to
secondary_current.

Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/include/asm/asm-prototypes.h |  4 ++--
 arch/powerpc/kernel/head_32.S             |  6 +++---
 arch/powerpc/kernel/head_44x.S            |  4 ++--
 arch/powerpc/kernel/head_fsl_booke.S      |  4 ++--
 arch/powerpc/kernel/smp.c                 | 10 ++++------
 5 files changed, 13 insertions(+), 15 deletions(-)

diff --git a/arch/powerpc/include/asm/asm-prototypes.h b/arch/powerpc/include/asm/asm-prototypes.h
index 1d911f68a23b..1484df6779ab 100644
--- a/arch/powerpc/include/asm/asm-prototypes.h
+++ b/arch/powerpc/include/asm/asm-prototypes.h
@@ -23,8 +23,8 @@
 #include <uapi/asm/ucontext.h>
 
 /* SMP */
-extern struct thread_info *current_set[NR_CPUS];
-extern struct thread_info *secondary_ti;
+extern struct task_struct *current_set[NR_CPUS];
+extern struct task_struct *secondary_current;
 void start_secondary(void *unused);
 
 /* kexec */
diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index 309a45779ad5..146385b1c2da 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -846,9 +846,9 @@ __secondary_start:
 #endif /* CONFIG_PPC_BOOK3S_32 */
 
 	/* get current's stack and current */
-	lis	r1,secondary_ti@ha
-	tophys(r1,r1)
-	lwz	r2,secondary_ti@l(r1)
+	lis	r2,secondary_current@ha
+	tophys(r2,r2)
+	lwz	r2,secondary_current@l(r2)
 	tophys(r1,r2)
 	lwz	r1,TASK_STACK(r1)
 
diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
index f94a93b6c2f2..37117ab11584 100644
--- a/arch/powerpc/kernel/head_44x.S
+++ b/arch/powerpc/kernel/head_44x.S
@@ -1020,8 +1020,8 @@ _GLOBAL(start_secondary_47x)
 	/* Now we can get our task struct and real stack pointer */
 
 	/* Get current's stack and current */
-	lis	r1,secondary_ti@ha
-	lwz	r2,secondary_ti@l(r1)
+	lis	r2,secondary_current@ha
+	lwz	r2,secondary_current@l(r2)
 	lwz	r1,TASK_STACK(r2)
 
 	/* Current stack pointer */
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 11f38adbe020..4ed2a7c8e89b 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -1091,8 +1091,8 @@ __secondary_start:
 	bl	call_setup_cpu
 
 	/* get current's stack and current */
-	lis	r1,secondary_ti@ha
-	lwz	r2,secondary_ti@l(r1)
+	lis	r2,secondary_current@ha
+	lwz	r2,secondary_current@l(r2)
 	lwz	r1,TASK_STACK(r2)
 
 	/* stack */
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index aa4517686f90..a41fa8924004 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -76,7 +76,7 @@
 static DEFINE_PER_CPU(int, cpu_state) = { 0 };
 #endif
 
-struct thread_info *secondary_ti;
+struct task_struct *secondary_current;
 bool has_big_cores;
 
 DEFINE_PER_CPU(cpumask_var_t, cpu_sibling_map);
@@ -664,7 +664,7 @@ void smp_send_stop(void)
 }
 #endif /* CONFIG_NMI_IPI */
 
-struct thread_info *current_set[NR_CPUS];
+struct task_struct *current_set[NR_CPUS];
 
 static void smp_store_cpu_info(int id)
 {
@@ -929,7 +929,7 @@ void smp_prepare_boot_cpu(void)
 	paca_ptrs[boot_cpuid]->__current = current;
 #endif
 	set_numa_node(numa_cpu_lookup_table[boot_cpuid]);
-	current_set[boot_cpuid] = task_thread_info(current);
+	current_set[boot_cpuid] = current;
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -1014,15 +1014,13 @@ static bool secondaries_inhibited(void)
 
 static void cpu_idle_thread_init(unsigned int cpu, struct task_struct *idle)
 {
-	struct thread_info *ti = task_thread_info(idle);
-
 #ifdef CONFIG_PPC64
 	paca_ptrs[cpu]->__current = idle;
 	paca_ptrs[cpu]->kstack = (unsigned long)task_stack_page(idle) +
 				 THREAD_SIZE - STACK_FRAME_OVERHEAD;
 #endif
 	idle->cpu = cpu;
-	secondary_ti = current_set[cpu] = ti;
+	secondary_current = current_set[cpu] = idle;
 }
 
 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
-- 
2.13.3


^ permalink raw reply	[flat|nested] 16+ messages in thread

* [PATCH v13 08/10] powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU
  2019-01-12  9:55 [PATCH v13 00/10] powerpc: Switch to CONFIG_THREAD_INFO_IN_TASK Christophe Leroy
                   ` (6 preceding siblings ...)
  2019-01-12  9:55 ` [PATCH v13 07/10] powerpc: 'current_set' is now a table of task_struct pointers Christophe Leroy
@ 2019-01-12  9:55 ` Christophe Leroy
  2019-01-12  9:55 ` [PATCH v13 09/10] powerpc/64: Remove CURRENT_THREAD_INFO Christophe Leroy
                   ` (3 subsequent siblings)
  11 siblings, 0 replies; 16+ messages in thread
From: Christophe Leroy @ 2019-01-12  9:55 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
	Nicholas Piggin, Mike Rapoport
  Cc: linuxppc-dev, linux-kernel

Now that thread_info is similar to task_struct, its address is in r2
so CURRENT_THREAD_INFO() macro is useless. This patch removes it.

At the same time, as the 'cpu' field is not anymore in thread_info,
this patch renames it to TASK_CPU.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/Makefile                  |  2 +-
 arch/powerpc/include/asm/thread_info.h |  2 --
 arch/powerpc/kernel/asm-offsets.c      |  2 +-
 arch/powerpc/kernel/entry_32.S         | 43 ++++++++++++----------------------
 arch/powerpc/kernel/epapr_hcalls.S     |  5 ++--
 arch/powerpc/kernel/head_fsl_booke.S   |  5 ++--
 arch/powerpc/kernel/idle_6xx.S         |  8 +++----
 arch/powerpc/kernel/idle_e500.S        |  8 +++----
 arch/powerpc/kernel/misc_32.S          |  3 +--
 arch/powerpc/mm/hash_low_32.S          | 14 ++++-------
 arch/powerpc/sysdev/6xx-suspend.S      |  5 ++--
 11 files changed, 35 insertions(+), 62 deletions(-)

diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 326e8ba6e314..5a9bf22a7534 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -431,7 +431,7 @@ ifdef CONFIG_SMP
 prepare: task_cpu_prepare
 
 task_cpu_prepare: prepare0
-	$(eval KBUILD_CFLAGS += -D_TASK_CPU=$(shell awk '{if ($$2 == "TI_CPU") print $$3;}' include/generated/asm-offsets.h))
+	$(eval KBUILD_CFLAGS += -D_TASK_CPU=$(shell awk '{if ($$2 == "TASK_CPU") print $$3;}' include/generated/asm-offsets.h))
 endif
 
 # Check toolchain versions:
diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index d91523c2c7d8..c959b8d66cac 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -19,8 +19,6 @@
 
 #ifdef CONFIG_PPC64
 #define CURRENT_THREAD_INFO(dest, sp)	stringify_in_c(ld dest, PACACURRENT(r13))
-#else
-#define CURRENT_THREAD_INFO(dest, sp)	stringify_in_c(mr dest, r2)
 #endif
 
 #ifndef __ASSEMBLY__
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 94ac190a0b16..03439785c2ea 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -96,7 +96,7 @@ int main(void)
 #endif /* CONFIG_PPC64 */
 	OFFSET(TASK_STACK, task_struct, stack);
 #ifdef CONFIG_SMP
-	OFFSET(TI_CPU, task_struct, cpu);
+	OFFSET(TASK_CPU, task_struct, cpu);
 #endif
 
 #ifdef CONFIG_LIVEPATCH
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index b547bd4168d8..52a061f14c7d 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -168,8 +168,7 @@ transfer_to_handler:
 	tophys(r11,r11)
 	addi	r11,r11,global_dbcr0@l
 #ifdef CONFIG_SMP
-	CURRENT_THREAD_INFO(r9, r1)
-	lwz	r9,TI_CPU(r9)
+	lwz	r9,TASK_CPU(r2)
 	slwi	r9,r9,3
 	add	r11,r11,r9
 #endif
@@ -180,8 +179,7 @@ transfer_to_handler:
 	stw	r12,4(r11)
 #endif
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
-	CURRENT_THREAD_INFO(r9, r1)
-	tophys(r9, r9)
+	tophys(r9, r2)
 	ACCOUNT_CPU_USER_ENTRY(r9, r11, r12)
 #endif
 
@@ -195,8 +193,7 @@ transfer_to_handler:
 	ble-	stack_ovf		/* then the kernel stack overflowed */
 5:
 #if defined(CONFIG_PPC_BOOK3S_32) || defined(CONFIG_E500)
-	CURRENT_THREAD_INFO(r9, r1)
-	tophys(r9,r9)			/* check local flags */
+	tophys(r9,r2)			/* check local flags */
 	lwz	r12,TI_LOCAL_FLAGS(r9)
 	mtcrf	0x01,r12
 	bt-	31-TLF_NAPPING,4f
@@ -345,8 +342,7 @@ _GLOBAL(DoSyscall)
 	mtmsr	r11
 1:
 #endif /* CONFIG_TRACE_IRQFLAGS */
-	CURRENT_THREAD_INFO(r10, r1)
-	lwz	r11,TI_FLAGS(r10)
+	lwz	r11,TI_FLAGS(r2)
 	andi.	r11,r11,_TIF_SYSCALL_DOTRACE
 	bne-	syscall_dotrace
 syscall_dotrace_cont:
@@ -379,13 +375,12 @@ ret_from_syscall:
 	lwz	r3,GPR3(r1)
 #endif
 	mr	r6,r3
-	CURRENT_THREAD_INFO(r12, r1)
 	/* disable interrupts so current_thread_info()->flags can't change */
 	LOAD_MSR_KERNEL(r10,MSR_KERNEL)	/* doesn't include MSR_EE */
 	/* Note: We don't bother telling lockdep about it */
 	SYNC
 	MTMSRD(r10)
-	lwz	r9,TI_FLAGS(r12)
+	lwz	r9,TI_FLAGS(r2)
 	li	r8,-MAX_ERRNO
 	andi.	r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)
 	bne-	syscall_exit_work
@@ -432,8 +427,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX)
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 	andi.	r4,r8,MSR_PR
 	beq	3f
-	CURRENT_THREAD_INFO(r4, r1)
-	ACCOUNT_CPU_USER_EXIT(r4, r5, r7)
+	ACCOUNT_CPU_USER_EXIT(r2, r5, r7)
 3:
 #endif
 	lwz	r4,_LINK(r1)
@@ -526,7 +520,7 @@ syscall_exit_work:
 	/* Clear per-syscall TIF flags if any are set.  */
 
 	li	r11,_TIF_PERSYSCALL_MASK
-	addi	r12,r12,TI_FLAGS
+	addi	r12,r2,TI_FLAGS
 3:	lwarx	r8,0,r12
 	andc	r8,r8,r11
 #ifdef CONFIG_IBM405_ERR77
@@ -534,7 +528,6 @@ syscall_exit_work:
 #endif
 	stwcx.	r8,0,r12
 	bne-	3b
-	subi	r12,r12,TI_FLAGS
 	
 4:	/* Anything which requires enabling interrupts? */
 	andi.	r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP)
@@ -813,8 +806,7 @@ ret_from_except:
 
 user_exc_return:		/* r10 contains MSR_KERNEL here */
 	/* Check current_thread_info()->flags */
-	CURRENT_THREAD_INFO(r9, r1)
-	lwz	r9,TI_FLAGS(r9)
+	lwz	r9,TI_FLAGS(r2)
 	andi.	r0,r9,_TIF_USER_WORK_MASK
 	bne	do_work
 
@@ -827,8 +819,7 @@ restore_user:
 	bnel-	load_dbcr0
 #endif
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
-	CURRENT_THREAD_INFO(r9, r1)
-	ACCOUNT_CPU_USER_EXIT(r9, r10, r11)
+	ACCOUNT_CPU_USER_EXIT(r2, r10, r11)
 #endif
 
 	b	restore
@@ -836,8 +827,7 @@ restore_user:
 /* N.B. the only way to get here is from the beq following ret_from_except. */
 resume_kernel:
 	/* check current_thread_info, _TIF_EMULATE_STACK_STORE */
-	CURRENT_THREAD_INFO(r9, r1)
-	lwz	r8,TI_FLAGS(r9)
+	lwz	r8,TI_FLAGS(r2)
 	andis.	r0,r8,_TIF_EMULATE_STACK_STORE@h
 	beq+	1f
 
@@ -863,7 +853,7 @@ resume_kernel:
 
 	/* Clear _TIF_EMULATE_STACK_STORE flag */
 	lis	r11,_TIF_EMULATE_STACK_STORE@h
-	addi	r5,r9,TI_FLAGS
+	addi	r5,r2,TI_FLAGS
 0:	lwarx	r8,0,r5
 	andc	r8,r8,r11
 #ifdef CONFIG_IBM405_ERR77
@@ -875,7 +865,7 @@ resume_kernel:
 
 #ifdef CONFIG_PREEMPT
 	/* check current_thread_info->preempt_count */
-	lwz	r0,TI_PREEMPT(r9)
+	lwz	r0,TI_PREEMPT(r2)
 	cmpwi	0,r0,0		/* if non-zero, just restore regs and return */
 	bne	restore
 	andi.	r8,r8,_TIF_NEED_RESCHED
@@ -891,8 +881,7 @@ resume_kernel:
 	bl	trace_hardirqs_off
 #endif
 1:	bl	preempt_schedule_irq
-	CURRENT_THREAD_INFO(r9, r1)
-	lwz	r3,TI_FLAGS(r9)
+	lwz	r3,TI_FLAGS(r2)
 	andi.	r0,r3,_TIF_NEED_RESCHED
 	bne-	1b
 #ifdef CONFIG_TRACE_IRQFLAGS
@@ -1191,8 +1180,7 @@ load_dbcr0:
 	lis	r11,global_dbcr0@ha
 	addi	r11,r11,global_dbcr0@l
 #ifdef CONFIG_SMP
-	CURRENT_THREAD_INFO(r9, r1)
-	lwz	r9,TI_CPU(r9)
+	lwz	r9,TASK_CPU(r2)
 	slwi	r9,r9,3
 	add	r11,r11,r9
 #endif
@@ -1232,8 +1220,7 @@ recheck:
 	LOAD_MSR_KERNEL(r10,MSR_KERNEL)
 	SYNC
 	MTMSRD(r10)		/* disable interrupts */
-	CURRENT_THREAD_INFO(r9, r1)
-	lwz	r9,TI_FLAGS(r9)
+	lwz	r9,TI_FLAGS(r2)
 	andi.	r0,r9,_TIF_NEED_RESCHED
 	bne-	do_resched
 	andi.	r0,r9,_TIF_USER_WORK_MASK
diff --git a/arch/powerpc/kernel/epapr_hcalls.S b/arch/powerpc/kernel/epapr_hcalls.S
index 52ca2471ee1a..d252f4663a23 100644
--- a/arch/powerpc/kernel/epapr_hcalls.S
+++ b/arch/powerpc/kernel/epapr_hcalls.S
@@ -21,10 +21,9 @@
 #ifndef CONFIG_PPC64
 /* epapr_ev_idle() was derived from e500_idle() */
 _GLOBAL(epapr_ev_idle)
-	CURRENT_THREAD_INFO(r3, r1)
-	PPC_LL	r4, TI_LOCAL_FLAGS(r3)	/* set napping bit */
+	PPC_LL	r4, TI_LOCAL_FLAGS(r2)	/* set napping bit */
 	ori	r4, r4,_TLF_NAPPING	/* so when we take an exception */
-	PPC_STL	r4, TI_LOCAL_FLAGS(r3)	/* it will return to our caller */
+	PPC_STL	r4, TI_LOCAL_FLAGS(r2)	/* it will return to our caller */
 
 	wrteei	1
 
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 4ed2a7c8e89b..1881127682e9 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -244,8 +244,7 @@ set_ivor:
 	stwu	r0,THREAD_SIZE-STACK_FRAME_OVERHEAD(r1)
 
 #ifdef CONFIG_SMP
-	CURRENT_THREAD_INFO(r22, r1)
-	stw	r24, TI_CPU(r22)
+	stw	r24, TASK_CPU(r2)
 #endif
 
 	bl	early_init
@@ -719,7 +718,7 @@ finish_tlb_load:
 
 	/* Get the next_tlbcam_idx percpu var */
 #ifdef CONFIG_SMP
-	lwz	r15, TI_CPU-THREAD(r12)
+	lwz	r15, TASK_CPU-THREAD(r12)
 	lis     r14, __per_cpu_offset@h
 	ori     r14, r14, __per_cpu_offset@l
 	rlwinm  r15, r15, 2, 0, 29
diff --git a/arch/powerpc/kernel/idle_6xx.S b/arch/powerpc/kernel/idle_6xx.S
index ff026c9d3cab..5afd2e236990 100644
--- a/arch/powerpc/kernel/idle_6xx.S
+++ b/arch/powerpc/kernel/idle_6xx.S
@@ -136,10 +136,9 @@ BEGIN_FTR_SECTION
 	DSSALL
 	sync
 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
-	CURRENT_THREAD_INFO(r9, r1)
-	lwz	r8,TI_LOCAL_FLAGS(r9)	/* set napping bit */
+	lwz	r8,TI_LOCAL_FLAGS(r2)	/* set napping bit */
 	ori	r8,r8,_TLF_NAPPING	/* so when we take an exception */
-	stw	r8,TI_LOCAL_FLAGS(r9)	/* it will return to our caller */
+	stw	r8,TI_LOCAL_FLAGS(r2)	/* it will return to our caller */
 	mfmsr	r7
 	ori	r7,r7,MSR_EE
 	oris	r7,r7,MSR_POW@h
@@ -159,8 +158,7 @@ _GLOBAL(power_save_ppc32_restore)
 	stw	r9,_NIP(r11)		/* make it do a blr */
 
 #ifdef CONFIG_SMP
-	CURRENT_THREAD_INFO(r12, r11)
-	lwz	r11,TI_CPU(r12)		/* get cpu number * 4 */
+	lwz	r11,TASK_CPU(r2)		/* get cpu number * 4 */
 	slwi	r11,r11,2
 #else
 	li	r11,0
diff --git a/arch/powerpc/kernel/idle_e500.S b/arch/powerpc/kernel/idle_e500.S
index 583e55ac7d26..69dfcd2ca011 100644
--- a/arch/powerpc/kernel/idle_e500.S
+++ b/arch/powerpc/kernel/idle_e500.S
@@ -22,10 +22,9 @@
 	.text
 
 _GLOBAL(e500_idle)
-	CURRENT_THREAD_INFO(r3, r1)
-	lwz	r4,TI_LOCAL_FLAGS(r3)	/* set napping bit */
+	lwz	r4,TI_LOCAL_FLAGS(r2)	/* set napping bit */
 	ori	r4,r4,_TLF_NAPPING	/* so when we take an exception */
-	stw	r4,TI_LOCAL_FLAGS(r3)	/* it will return to our caller */
+	stw	r4,TI_LOCAL_FLAGS(r2)	/* it will return to our caller */
 
 #ifdef CONFIG_PPC_E500MC
 	wrteei	1
@@ -88,8 +87,7 @@ _GLOBAL(power_save_ppc32_restore)
 	stw	r9,_NIP(r11)		/* make it do a blr */
 
 #ifdef CONFIG_SMP
-	CURRENT_THREAD_INFO(r12, r1)
-	lwz	r11,TI_CPU(r12)		/* get cpu number * 4 */
+	lwz	r11,TASK_CPU(r2)		/* get cpu number * 4 */
 	slwi	r11,r11,2
 #else
 	li	r11,0
diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index 6f6127c3760c..0dda4f8e3d7a 100644
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -183,8 +183,7 @@ _GLOBAL(low_choose_750fx_pll)
 
 #ifdef CONFIG_SMP
 	/* Store new HID1 image */
-	CURRENT_THREAD_INFO(r6, r1)
-	lwz	r6,TI_CPU(r6)
+	lwz	r6,TASK_CPU(r2)
 	slwi	r6,r6,2
 #else
 	li	r6, 0
diff --git a/arch/powerpc/mm/hash_low_32.S b/arch/powerpc/mm/hash_low_32.S
index 1e2df3e9f9ea..5bee2d982959 100644
--- a/arch/powerpc/mm/hash_low_32.S
+++ b/arch/powerpc/mm/hash_low_32.S
@@ -186,8 +186,7 @@ _GLOBAL(add_hash_page)
 	add	r3,r3,r0		/* note create_hpte trims to 24 bits */
 
 #ifdef CONFIG_SMP
-	CURRENT_THREAD_INFO(r8, r1)	/* use cpu number to make tag */
-	lwz	r8,TI_CPU(r8)		/* to go in mmu_hash_lock */
+	lwz	r8,TASK_CPU(r2)		/* to go in mmu_hash_lock */
 	oris	r8,r8,12
 #endif /* CONFIG_SMP */
 
@@ -549,9 +548,8 @@ _GLOBAL(flush_hash_pages)
 #ifdef CONFIG_SMP
 	addis	r9,r7,mmu_hash_lock@ha
 	addi	r9,r9,mmu_hash_lock@l
-	CURRENT_THREAD_INFO(r8, r1)
-	add	r8,r8,r7
-	lwz	r8,TI_CPU(r8)
+	add	r8,r2,r7
+	lwz	r8,TASK_CPU(r8)
 	oris	r8,r8,9
 10:	lwarx	r0,0,r9
 	cmpi	0,r0,0
@@ -646,8 +644,7 @@ EXPORT_SYMBOL(flush_hash_pages)
  */
 _GLOBAL(_tlbie)
 #ifdef CONFIG_SMP
-	CURRENT_THREAD_INFO(r8, r1)
-	lwz	r8,TI_CPU(r8)
+	lwz	r8,TASK_CPU(r2)
 	oris	r8,r8,11
 	mfmsr	r10
 	SYNC
@@ -684,8 +681,7 @@ _GLOBAL(_tlbie)
  */
 _GLOBAL(_tlbia)
 #if defined(CONFIG_SMP)
-	CURRENT_THREAD_INFO(r8, r1)
-	lwz	r8,TI_CPU(r8)
+	lwz	r8,TASK_CPU(r2)
 	oris	r8,r8,10
 	mfmsr	r10
 	SYNC
diff --git a/arch/powerpc/sysdev/6xx-suspend.S b/arch/powerpc/sysdev/6xx-suspend.S
index cf48e9cb2575..6c4aec25c4ba 100644
--- a/arch/powerpc/sysdev/6xx-suspend.S
+++ b/arch/powerpc/sysdev/6xx-suspend.S
@@ -29,10 +29,9 @@ _GLOBAL(mpc6xx_enter_standby)
 	ori	r5, r5, ret_from_standby@l
 	mtlr	r5
 
-	CURRENT_THREAD_INFO(r5, r1)
-	lwz	r6, TI_LOCAL_FLAGS(r5)
+	lwz	r6, TI_LOCAL_FLAGS(r2)
 	ori	r6, r6, _TLF_SLEEPING
-	stw	r6, TI_LOCAL_FLAGS(r5)
+	stw	r6, TI_LOCAL_FLAGS(r2)
 
 	mfmsr	r5
 	ori	r5, r5, MSR_EE
-- 
2.13.3


^ permalink raw reply	[flat|nested] 16+ messages in thread

* [PATCH v13 09/10] powerpc/64: Remove CURRENT_THREAD_INFO
  2019-01-12  9:55 [PATCH v13 00/10] powerpc: Switch to CONFIG_THREAD_INFO_IN_TASK Christophe Leroy
                   ` (7 preceding siblings ...)
  2019-01-12  9:55 ` [PATCH v13 08/10] powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU Christophe Leroy
@ 2019-01-12  9:55 ` Christophe Leroy
  2019-01-12  9:55 ` [PATCH v13 10/10] powerpc: clean stack pointers naming Christophe Leroy
                   ` (2 subsequent siblings)
  11 siblings, 0 replies; 16+ messages in thread
From: Christophe Leroy @ 2019-01-12  9:55 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
	Nicholas Piggin, Mike Rapoport
  Cc: linuxppc-dev, linux-kernel

Now that current_thread_info is located at the beginning of 'current'
task struct, CURRENT_THREAD_INFO macro is not really needed any more.

This patch replaces it by loads of the value at PACACURRENT(r13).

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/include/asm/exception-64s.h       |  4 ++--
 arch/powerpc/include/asm/thread_info.h         |  4 ----
 arch/powerpc/kernel/entry_64.S                 | 10 +++++-----
 arch/powerpc/kernel/exceptions-64e.S           |  2 +-
 arch/powerpc/kernel/exceptions-64s.S           |  2 +-
 arch/powerpc/kernel/idle_book3e.S              |  2 +-
 arch/powerpc/kernel/idle_power4.S              |  2 +-
 arch/powerpc/kernel/trace/ftrace_64_mprofile.S |  6 +++---
 8 files changed, 14 insertions(+), 18 deletions(-)

diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index 3b4767ed3ec5..dd6a5ae7a769 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -671,7 +671,7 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
 
 #define RUNLATCH_ON				\
 BEGIN_FTR_SECTION				\
-	CURRENT_THREAD_INFO(r3, r1);		\
+	ld	r3, PACACURRENT(r13);		\
 	ld	r4,TI_LOCAL_FLAGS(r3);		\
 	andi.	r0,r4,_TLF_RUNLATCH;		\
 	beql	ppc64_runlatch_on_trampoline;	\
@@ -721,7 +721,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_CTRL)
 #ifdef CONFIG_PPC_970_NAP
 #define FINISH_NAP				\
 BEGIN_FTR_SECTION				\
-	CURRENT_THREAD_INFO(r11, r1);		\
+	ld	r11, PACACURRENT(r13);		\
 	ld	r9,TI_LOCAL_FLAGS(r11);		\
 	andi.	r10,r9,_TLF_NAPPING;		\
 	bnel	power4_fixup_nap;		\
diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index c959b8d66cac..8e1d0195ac36 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -17,10 +17,6 @@
 
 #define THREAD_SIZE		(1 << THREAD_SHIFT)
 
-#ifdef CONFIG_PPC64
-#define CURRENT_THREAD_INFO(dest, sp)	stringify_in_c(ld dest, PACACURRENT(r13))
-#endif
-
 #ifndef __ASSEMBLY__
 #include <linux/cache.h>
 #include <asm/processor.h>
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 01d0706d873f..83bddacd7a17 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -166,7 +166,7 @@ system_call:			/* label this so stack traces look sane */
 	li	r10,IRQS_ENABLED
 	std	r10,SOFTE(r1)
 
-	CURRENT_THREAD_INFO(r11, r1)
+	ld	r11, PACACURRENT(r13)
 	ld	r10,TI_FLAGS(r11)
 	andi.	r11,r10,_TIF_SYSCALL_DOTRACE
 	bne	.Lsyscall_dotrace		/* does not return */
@@ -213,7 +213,7 @@ system_call:			/* label this so stack traces look sane */
 	ld	r3,RESULT(r1)
 #endif
 
-	CURRENT_THREAD_INFO(r12, r1)
+	ld	r12, PACACURRENT(r13)
 
 	ld	r8,_MSR(r1)
 #ifdef CONFIG_PPC_BOOK3S
@@ -348,7 +348,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 
 	/* Repopulate r9 and r10 for the syscall path */
 	addi	r9,r1,STACK_FRAME_OVERHEAD
-	CURRENT_THREAD_INFO(r10, r1)
+	ld	r10, PACACURRENT(r13)
 	ld	r10,TI_FLAGS(r10)
 
 	cmpldi	r0,NR_syscalls
@@ -746,7 +746,7 @@ _GLOBAL(ret_from_except_lite)
 	mtmsrd	r10,1		  /* Update machine state */
 #endif /* CONFIG_PPC_BOOK3E */
 
-	CURRENT_THREAD_INFO(r9, r1)
+	ld	r9, PACACURRENT(r13)
 	ld	r3,_MSR(r1)
 #ifdef CONFIG_PPC_BOOK3E
 	ld	r10,PACACURRENT(r13)
@@ -860,7 +860,7 @@ resume_kernel:
 1:	bl	preempt_schedule_irq
 
 	/* Re-test flags and eventually loop */
-	CURRENT_THREAD_INFO(r9, r1)
+	ld	r9, PACACURRENT(r13)
 	ld	r4,TI_FLAGS(r9)
 	andi.	r0,r4,_TIF_NEED_RESCHED
 	bne	1b
diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S
index 20f14996281d..04ee24789f80 100644
--- a/arch/powerpc/kernel/exceptions-64e.S
+++ b/arch/powerpc/kernel/exceptions-64e.S
@@ -493,7 +493,7 @@ exc_##n##_bad_stack:							    \
  * interrupts happen before the wait instruction.
  */
 #define CHECK_NAPPING()							\
-	CURRENT_THREAD_INFO(r11, r1);					\
+	ld	r11, PACACURRENT(r13);					\
 	ld	r10,TI_LOCAL_FLAGS(r11);				\
 	andi.	r9,r10,_TLF_NAPPING;					\
 	beq+	1f;							\
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 9e253ce27e08..c7c4e2d6f98f 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1629,7 +1629,7 @@ do_hash_page:
 	ori	r0,r0,DSISR_BAD_FAULT_64S@l
 	and.	r0,r4,r0		/* weird error? */
 	bne-	handle_page_fault	/* if not, try to insert a HPTE */
-	CURRENT_THREAD_INFO(r11, r1)
+	ld	r11, PACACURRENT(r13)
 	lwz	r0,TI_PREEMPT(r11)	/* If we're in an "NMI" */
 	andis.	r0,r0,NMI_MASK@h	/* (i.e. an irq when soft-disabled) */
 	bne	77f			/* then don't call hash_page now */
diff --git a/arch/powerpc/kernel/idle_book3e.S b/arch/powerpc/kernel/idle_book3e.S
index 4e0d94d02030..31e732c378ad 100644
--- a/arch/powerpc/kernel/idle_book3e.S
+++ b/arch/powerpc/kernel/idle_book3e.S
@@ -63,7 +63,7 @@ _GLOBAL(\name)
 1:	/* Let's set the _TLF_NAPPING flag so interrupts make us return
 	 * to the right spot
 	*/
-	CURRENT_THREAD_INFO(r11, r1)
+	ld	r11, PACACURRENT(r13)
 	ld	r10,TI_LOCAL_FLAGS(r11)
 	ori	r10,r10,_TLF_NAPPING
 	std	r10,TI_LOCAL_FLAGS(r11)
diff --git a/arch/powerpc/kernel/idle_power4.S b/arch/powerpc/kernel/idle_power4.S
index a09b3c7ca176..61ac89fd0a05 100644
--- a/arch/powerpc/kernel/idle_power4.S
+++ b/arch/powerpc/kernel/idle_power4.S
@@ -68,7 +68,7 @@ BEGIN_FTR_SECTION
 	DSSALL
 	sync
 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
-	CURRENT_THREAD_INFO(r9, r1)
+	ld	r9, PACACURRENT(r13)
 	ld	r8,TI_LOCAL_FLAGS(r9)	/* set napping bit */
 	ori	r8,r8,_TLF_NAPPING	/* so when we take an exception */
 	std	r8,TI_LOCAL_FLAGS(r9)	/* it will return to our caller */
diff --git a/arch/powerpc/kernel/trace/ftrace_64_mprofile.S b/arch/powerpc/kernel/trace/ftrace_64_mprofile.S
index 32476a6e4e9c..202bec086e3b 100644
--- a/arch/powerpc/kernel/trace/ftrace_64_mprofile.S
+++ b/arch/powerpc/kernel/trace/ftrace_64_mprofile.S
@@ -229,7 +229,7 @@ ftrace_call:
 	 *  - r0, r11 & r12 are free
 	 */
 livepatch_handler:
-	CURRENT_THREAD_INFO(r12, r1)
+	ld	r12, PACACURRENT(r13)
 
 	/* Allocate 3 x 8 bytes */
 	ld	r11, TI_livepatch_sp(r12)
@@ -256,7 +256,7 @@ livepatch_handler:
 	 * restore it.
 	 */
 
-	CURRENT_THREAD_INFO(r12, r1)
+	ld	r12, PACACURRENT(r13)
 
 	ld	r11, TI_livepatch_sp(r12)
 
@@ -273,7 +273,7 @@ livepatch_handler:
 	ld	r2,  -24(r11)
 
 	/* Pop livepatch stack frame */
-	CURRENT_THREAD_INFO(r12, r1)
+	ld	r12, PACACURRENT(r13)
 	subi	r11, r11, 24
 	std	r11, TI_livepatch_sp(r12)
 
-- 
2.13.3


^ permalink raw reply	[flat|nested] 16+ messages in thread

* [PATCH v13 10/10] powerpc: clean stack pointers naming
  2019-01-12  9:55 [PATCH v13 00/10] powerpc: Switch to CONFIG_THREAD_INFO_IN_TASK Christophe Leroy
                   ` (8 preceding siblings ...)
  2019-01-12  9:55 ` [PATCH v13 09/10] powerpc/64: Remove CURRENT_THREAD_INFO Christophe Leroy
@ 2019-01-12  9:55 ` Christophe Leroy
  2019-01-19 10:23 ` [PATCH v13 00/10] powerpc: Switch to CONFIG_THREAD_INFO_IN_TASK Michael Ellerman
  2019-01-23 10:04 ` Christophe Leroy
  11 siblings, 0 replies; 16+ messages in thread
From: Christophe Leroy @ 2019-01-12  9:55 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
	Nicholas Piggin, Mike Rapoport
  Cc: linuxppc-dev, linux-kernel

Some stack pointers used to also be thread_info pointers
and were called tp. Now that they are only stack pointers,
rename them sp.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/kernel/irq.c      | 17 +++++++----------
 arch/powerpc/kernel/setup_64.c | 11 +++--------
 2 files changed, 10 insertions(+), 18 deletions(-)

diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 1aef9316345f..983e53b427c0 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -659,21 +659,21 @@ void __do_irq(struct pt_regs *regs)
 void do_IRQ(struct pt_regs *regs)
 {
 	struct pt_regs *old_regs = set_irq_regs(regs);
-	void *curtp, *irqtp, *sirqtp;
+	void *cursp, *irqsp, *sirqsp;
 
 	/* Switch to the irq stack to handle this */
-	curtp = (void *)(current_stack_pointer() & ~(THREAD_SIZE - 1));
-	irqtp = hardirq_ctx[raw_smp_processor_id()];
-	sirqtp = softirq_ctx[raw_smp_processor_id()];
+	cursp = (void *)(current_stack_pointer() & ~(THREAD_SIZE - 1));
+	irqsp = hardirq_ctx[raw_smp_processor_id()];
+	sirqsp = softirq_ctx[raw_smp_processor_id()];
 
 	/* Already there ? */
-	if (unlikely(curtp == irqtp || curtp == sirqtp)) {
+	if (unlikely(cursp == irqsp || cursp == sirqsp)) {
 		__do_irq(regs);
 		set_irq_regs(old_regs);
 		return;
 	}
 	/* Switch stack and call */
-	call_do_irq(regs, irqtp);
+	call_do_irq(regs, irqsp);
 
 	set_irq_regs(old_regs);
 }
@@ -695,10 +695,7 @@ void *hardirq_ctx[NR_CPUS] __read_mostly;
 
 void do_softirq_own_stack(void)
 {
-	void *irqtp;
-
-	irqtp = softirq_ctx[smp_processor_id()];
-	call_do_softirq(irqtp);
+	call_do_softirq(softirq_ctx[smp_processor_id()]);
 }
 
 irq_hw_number_t virq_to_hw(unsigned int virq)
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 2db1c5f7d141..daa361fc6a24 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -716,19 +716,14 @@ void __init emergency_stack_init(void)
 	limit = min(ppc64_bolted_size(), ppc64_rma_size);
 
 	for_each_possible_cpu(i) {
-		void *ti;
-
-		ti = alloc_stack(limit, i);
-		paca_ptrs[i]->emergency_sp = ti + THREAD_SIZE;
+		paca_ptrs[i]->emergency_sp = alloc_stack(limit, i) + THREAD_SIZE;
 
 #ifdef CONFIG_PPC_BOOK3S_64
 		/* emergency stack for NMI exception handling. */
-		ti = alloc_stack(limit, i);
-		paca_ptrs[i]->nmi_emergency_sp = ti + THREAD_SIZE;
+		paca_ptrs[i]->nmi_emergency_sp = alloc_stack(limit, i) + THREAD_SIZE;
 
 		/* emergency stack for machine check exception handling. */
-		ti = alloc_stack(limit, i);
-		paca_ptrs[i]->mc_emergency_sp = ti + THREAD_SIZE;
+		paca_ptrs[i]->mc_emergency_sp = alloc_stack(limit, i) + THREAD_SIZE;
 #endif
 	}
 }
-- 
2.13.3


^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH v13 00/10] powerpc: Switch to CONFIG_THREAD_INFO_IN_TASK
  2019-01-12  9:55 [PATCH v13 00/10] powerpc: Switch to CONFIG_THREAD_INFO_IN_TASK Christophe Leroy
                   ` (9 preceding siblings ...)
  2019-01-12  9:55 ` [PATCH v13 10/10] powerpc: clean stack pointers naming Christophe Leroy
@ 2019-01-19 10:23 ` Michael Ellerman
  2019-01-19 17:21   ` LEROY Christophe
  2019-01-22 19:42   ` Christophe Leroy
  2019-01-23 10:04 ` Christophe Leroy
  11 siblings, 2 replies; 16+ messages in thread
From: Michael Ellerman @ 2019-01-19 10:23 UTC (permalink / raw)
  To: Christophe Leroy, Benjamin Herrenschmidt, Paul Mackerras,
	Nicholas Piggin, Mike Rapoport
  Cc: linuxppc-dev, linux-kernel

Christophe Leroy <christophe.leroy@c-s.fr> writes:

> The purpose of this serie is to activate CONFIG_THREAD_INFO_IN_TASK which
> moves the thread_info into task_struct.
>
> Moving thread_info into task_struct has the following advantages:
> - It protects thread_info from corruption in the case of stack
> overflows.
> - Its address is harder to determine if stack addresses are
> leaked, making a number of attacks more difficult.
>
> Changes since v12:
>  - Patch 1: Taken comment from Mike (re-introduced the 'panic' in case memblock allocation fails in setup_64.c
>  - Patch 1: Added alloc_stack() function in setup_32.c to also panic in case of allocation failure.

Hi Christophe,

I can't get this series to boot on qemu mac99. I'm getting eg:

[    0.981514] NFS: Registering the id_resolver key type
[    0.981752] Key type id_resolver registered
[    0.981868] Key type id_legacy registered
[    0.995711] Unrecoverable exception 0 at 0 (msr=0)
[    0.996091] Oops: Unrecoverable exception, sig: 6 [#1]
[    0.996314] BE PAGE_SIZE=4K MMU=Hash PowerMac
[    0.996617] Modules linked in:
[    0.996869] CPU: 0 PID: 416 Comm: modprobe Not tainted 5.0.0-rc2-gcc-7.3.0-00043-g53f2de798792 #342
[    0.997138] NIP:  00000000 LR: 00000000 CTR: 00000000
[    0.997309] REGS: ef237f50 TRAP: 0000   Not tainted  (5.0.0-rc2-gcc-7.3.0-00043-g53f2de798792)
[    0.997508] MSR:  00000000 <>  CR: 00000000  XER: 00000000
[    0.997712] 
[    0.997712] GPR00: 00000000 ef238000 00000000 00000000 00000000 00000000 00000000 00000000 
[    0.997712] GPR08: 00000000 00000000 00000000 00000000 00000000 00000000 c006477c ef13d8c0 
[    0.997712] GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 
[    0.997712] GPR24: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 
[    0.998671] NIP [00000000]   (null)
[    0.998774] LR [00000000]   (null)
[    0.998895] Call Trace:
[    0.999030] Instruction dump:
[    0.999320] XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX 
[    0.999546] XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX 60000000 XXXXXXXX XXXXXXXX XXXXXXXX 
[    1.000023] ---[ end trace 925ea3419844fe68 ]---

I haven't had time to dig any further.

cheers

^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH v13 00/10] powerpc: Switch to CONFIG_THREAD_INFO_IN_TASK
  2019-01-19 10:23 ` [PATCH v13 00/10] powerpc: Switch to CONFIG_THREAD_INFO_IN_TASK Michael Ellerman
@ 2019-01-19 17:21   ` LEROY Christophe
  2019-01-23 23:10     ` Michael Ellerman
  2019-01-22 19:42   ` Christophe Leroy
  1 sibling, 1 reply; 16+ messages in thread
From: LEROY Christophe @ 2019-01-19 17:21 UTC (permalink / raw)
  To: Michael Ellerman
  Cc: linux-kernel, Nicholas Piggin, Mike Rapoport, Paul Mackerras,
	linuxppc-dev

Michael Ellerman <mpe@ellerman.id.au> a écrit :

> Christophe Leroy <christophe.leroy@c-s.fr> writes:
>
>> The purpose of this serie is to activate CONFIG_THREAD_INFO_IN_TASK which
>> moves the thread_info into task_struct.
>>
>> Moving thread_info into task_struct has the following advantages:
>> - It protects thread_info from corruption in the case of stack
>> overflows.
>> - Its address is harder to determine if stack addresses are
>> leaked, making a number of attacks more difficult.
>>
>> Changes since v12:
>>  - Patch 1: Taken comment from Mike (re-introduced the 'panic' in  
>> case memblock allocation fails in setup_64.c
>>  - Patch 1: Added alloc_stack() function in setup_32.c to also  
>> panic in case of allocation failure.
>
> Hi Christophe,
>
> I can't get this series to boot on qemu mac99. I'm getting eg:

Problem new with version 13 or it is the first time you test ?

>
> [    0.981514] NFS: Registering the id_resolver key type
> [    0.981752] Key type id_resolver registered
> [    0.981868] Key type id_legacy registered
> [    0.995711] Unrecoverable exception 0 at 0 (msr=0)
> [    0.996091] Oops: Unrecoverable exception, sig: 6 [#1]
> [    0.996314] BE PAGE_SIZE=4K MMU=Hash PowerMac
> [    0.996617] Modules linked in:
> [    0.996869] CPU: 0 PID: 416 Comm: modprobe Not tainted  
> 5.0.0-rc2-gcc-7.3.0-00043-g53f2de798792 #342

Comm:modprobe  ==> Something wrong with modules ? I never tested with  
CONFIG_MODULES.

Christophe

> [    0.997138] NIP:  00000000 LR: 00000000 CTR: 00000000
> [    0.997309] REGS: ef237f50 TRAP: 0000   Not tainted   
> (5.0.0-rc2-gcc-7.3.0-00043-g53f2de798792)
> [    0.997508] MSR:  00000000 <>  CR: 00000000  XER: 00000000
> [    0.997712]
> [    0.997712] GPR00: 00000000 ef238000 00000000 00000000 00000000  
> 00000000 00000000 00000000
> [    0.997712] GPR08: 00000000 00000000 00000000 00000000 00000000  
> 00000000 c006477c ef13d8c0
> [    0.997712] GPR16: 00000000 00000000 00000000 00000000 00000000  
> 00000000 00000000 00000000
> [    0.997712] GPR24: 00000000 00000000 00000000 00000000 00000000  
> 00000000 00000000 00000000
> [    0.998671] NIP [00000000]   (null)
> [    0.998774] LR [00000000]   (null)
> [    0.998895] Call Trace:
> [    0.999030] Instruction dump:
> [    0.999320] XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX  
> XXXXXXXX XXXXXXXX
> [    0.999546] XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX 60000000 XXXXXXXX  
> XXXXXXXX XXXXXXXX
> [    1.000023] ---[ end trace 925ea3419844fe68 ]---
>
> I haven't had time to dig any further.
>
> cheers



^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH v13 00/10] powerpc: Switch to CONFIG_THREAD_INFO_IN_TASK
  2019-01-19 10:23 ` [PATCH v13 00/10] powerpc: Switch to CONFIG_THREAD_INFO_IN_TASK Michael Ellerman
  2019-01-19 17:21   ` LEROY Christophe
@ 2019-01-22 19:42   ` Christophe Leroy
  1 sibling, 0 replies; 16+ messages in thread
From: Christophe Leroy @ 2019-01-22 19:42 UTC (permalink / raw)
  To: Michael Ellerman, Benjamin Herrenschmidt, Paul Mackerras,
	Nicholas Piggin, Mike Rapoport
  Cc: linuxppc-dev, linux-kernel



Le 19/01/2019 à 11:23, Michael Ellerman a écrit :
> Christophe Leroy <christophe.leroy@c-s.fr> writes:
> 
>> The purpose of this serie is to activate CONFIG_THREAD_INFO_IN_TASK which
>> moves the thread_info into task_struct.
>>
>> Moving thread_info into task_struct has the following advantages:
>> - It protects thread_info from corruption in the case of stack
>> overflows.
>> - Its address is harder to determine if stack addresses are
>> leaked, making a number of attacks more difficult.
>>
>> Changes since v12:
>>   - Patch 1: Taken comment from Mike (re-introduced the 'panic' in case memblock allocation fails in setup_64.c
>>   - Patch 1: Added alloc_stack() function in setup_32.c to also panic in case of allocation failure.
> 
> Hi Christophe,
> 
> I can't get this series to boot on qemu mac99. I'm getting eg:
> 
> [    0.981514] NFS: Registering the id_resolver key type
> [    0.981752] Key type id_resolver registered
> [    0.981868] Key type id_legacy registered
> [    0.995711] Unrecoverable exception 0 at 0 (msr=0)
> [    0.996091] Oops: Unrecoverable exception, sig: 6 [#1]
> [    0.996314] BE PAGE_SIZE=4K MMU=Hash PowerMac
> [    0.996617] Modules linked in:
> [    0.996869] CPU: 0 PID: 416 Comm: modprobe Not tainted 5.0.0-rc2-gcc-7.3.0-00043-g53f2de798792 #342
> [    0.997138] NIP:  00000000 LR: 00000000 CTR: 00000000
> [    0.997309] REGS: ef237f50 TRAP: 0000   Not tainted  (5.0.0-rc2-gcc-7.3.0-00043-g53f2de798792)
> [    0.997508] MSR:  00000000 <>  CR: 00000000  XER: 00000000
> [    0.997712]
> [    0.997712] GPR00: 00000000 ef238000 00000000 00000000 00000000 00000000 00000000 00000000
> [    0.997712] GPR08: 00000000 00000000 00000000 00000000 00000000 00000000 c006477c ef13d8c0
> [    0.997712] GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> [    0.997712] GPR24: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> [    0.998671] NIP [00000000]   (null)
> [    0.998774] LR [00000000]   (null)
> [    0.998895] Call Trace:
> [    0.999030] Instruction dump:
> [    0.999320] XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
> [    0.999546] XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX 60000000 XXXXXXXX XXXXXXXX XXXXXXXX
> [    1.000023] ---[ end trace 925ea3419844fe68 ]---

No such issue on my side. Do you have a ramdisk with anythink special or 
a special config ? I see your kernel is modprobing something, know what 
it is ?

Especially, what is the amount of memory in your config ? On my side 
there is 128M:

Memory: 120292K/131072K available (6116K kernel code, 572K rwdata, 2036K 
rodata,
  340K init, 191K bss, 10780K reserved, 0K cma-reserved, 0K highmem)
Kernel virtual memory layout:
   * 0xfffcf000..0xfffff000  : fixmap
   * 0xff800000..0xffc00000  : highmem PTEs
   * 0xfef36000..0xff800000  : early ioremap
   * 0xc9000000..0xfef36000  : vmalloc & ioremap

This means the addresses in which your kernel faults are in vmalloc 
area. It's not normal I believe, is it ?

On my side it gives the following on qemu mac99 (I have no disk).

[...]
Initialise system trusted keyrings
workingset: timestamp_bits=30 max_order=15 bucket_order=0
NFS: Registering the id_resolver key type
Key type id_resolver registered
Key type id_legacy registered
Key type asymmetric registered
Asymmetric key parser 'x509' registered
Block layer SCSI generic (bsg) driver version 0.4 loaded (major 253)
io scheduler mq-deadline registered
io scheduler kyber registered
Using unsupported 800x600 (null) at 81000000, depth=32, pitch=3200
Console: switching to colour frame buffer device 100x37
fb0: Open Firmware frame buffer device on /pci@f2000000/QEMU,VGA@e
Generic non-volatile memory driver v1.1
brd: module loaded
loop: module loaded
MacIO PCI driver attached to Keylargo chipset
Macintosh Cuda and Egret driver.
mesh: configured for synchronous 5 MB/s
st: Version 20160209, fixed bufsize 32768, s/g segs 256
Detected ADB keyboard, type ANSI.
input: ADB keyboard as /devices/virtual/input/input0
random: fast init done
input: ADB mouse as /devices/virtual/input/input1
pata-macio 0.00020000:ata-3: Activating pata-macio chipset KeyLargo 
ATA-3, Apple
  bus ID 0
scsi host0: pata_macio
ata1: PATA max MWDMA2 irq 16
pata-macio 0.00021000:ata-3: Activating pata-macio chipset KeyLargo 
ATA-3, Apple
  bus ID 1
scsi host1: pata_macio
ata2: PATA max MWDMA2 irq 18
pcnet32: pcnet32.c:v1.35 21.Apr.2008 tsbogend@alpha.franken.de
PPP generic driver version 2.4.2
PPP Deflate Compression module registered
ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver
ohci-pci: OHCI PCI platform driver
ohci-pci 0000:00:0d.0: OHCI PCI host controller
ohci-pci 0000:00:0d.0: new USB bus registered, assigned bus number 1
ohci-pci 0000:00:0d.0: irq 28, io mem 0x80080000
hub 1-0:1.0: USB hub found
hub 1-0:1.0: 3 ports detected
usbcore: registered new interface driver appletouch
rtc-generic rtc-generic: registered as rtc0
APM Battery Driver
usbcore: registered new interface driver usbhid
usbhid: USB HID core driver
oprofile: using timer interrupt.
Initializing XFRM netlink socket
NET: Registered protocol family 17
NET: Registered protocol family 15
Key type dns_resolver registered
drmem: No dynamic reconfiguration memory found
Loading compiled-in X.509 certificates
rtc-generic rtc-generic: setting system clock to 2019-01-22T19:35:11 UTC 
(154818
5711)
Warning: unable to open an initial console.
ata2.00: ATAPI: QEMU DVD-ROM, 2.5+, max UDMA/100
scsi 1:0:0:0: CD-ROM            QEMU     QEMU DVD-ROM     2.5+ PQ: 0 ANSI: 5
sr 1:0:0:0: [sr0] scsi3-mmc drive: 4x/4x cd/rw xa/form2 tray
cdrom: Uniform CD-ROM driver Revision: 3.20
sr 1:0:0:0: Attached scsi generic sg0 type 5
VFS: Cannot open root device "(null)" or unknown-block(8,1): error -6
Please append a correct "root=" boot option; here are the available 
partitions:
0100            4096 ram0
  (driver?)
0101            4096 ram1
  (driver?)
0102            4096 ram2
  (driver?)
0103            4096 ram3
  (driver?)
0104            4096 ram4
  (driver?)
0105            4096 ram5
  (driver?)
0106            4096 ram6
  (driver?)
0107            4096 ram7
  (driver?)
0108            4096 ram8
  (driver?)
0109            4096 ram9
  (driver?)
010a            4096 ram10
  (driver?)
010b            4096 ram11
  (driver?)
010c            4096 ram12
  (driver?)
010d            4096 ram13
  (driver?)
010e            4096 ram14
  (driver?)
010f            4096 ram15
  (driver?)
0b00         1048575 sr0
  driver: sr
Kernel panic - not syncing: VFS: Unable to mount root fs on 
unknown-block(8,1)
CPU: 0 PID: 1 Comm: swapper Not tainted 5.0.0-rc3+ #790
Call Trace:
[c7837e60] [c003dcf0] panic+0x12c/0x2e8 (unreliable)
[c7837ec0] [c07fc824] mount_block_root+0x1fc/0x2c0
[c7837f10] [c07fcc54] prepare_namespace+0x198/0x1d4
[c7837f30] [c000539c] kernel_init+0x18/0x10c
[c7837f40] [c00131d8] ret_from_kernel_thread+0x14/0x1c
Rebooting in 180 seconds..

Christophe

^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH v13 00/10] powerpc: Switch to CONFIG_THREAD_INFO_IN_TASK
  2019-01-12  9:55 [PATCH v13 00/10] powerpc: Switch to CONFIG_THREAD_INFO_IN_TASK Christophe Leroy
                   ` (10 preceding siblings ...)
  2019-01-19 10:23 ` [PATCH v13 00/10] powerpc: Switch to CONFIG_THREAD_INFO_IN_TASK Michael Ellerman
@ 2019-01-23 10:04 ` Christophe Leroy
  11 siblings, 0 replies; 16+ messages in thread
From: Christophe Leroy @ 2019-01-23 10:04 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
	Nicholas Piggin
  Cc: linuxppc-dev, linux-kernel, Mike Rapoport



Le 12/01/2019 à 10:55, Christophe Leroy a écrit :
> The purpose of this serie is to activate CONFIG_THREAD_INFO_IN_TASK which
> moves the thread_info into task_struct.
> 
> Moving thread_info into task_struct has the following advantages:
> - It protects thread_info from corruption in the case of stack
> overflows.
> - Its address is harder to determine if stack addresses are
> leaked, making a number of attacks more difficult.

I ran null_syscall and context_switch benchmark selftests and the result 
is surprising. There is slight degradation in context_switch and a 
significant one on null_syscall:

Without the serie:

~# chrt -f 98 ./context_switch --no-altivec --no-vector --no-fp
55542
55562
55564
55562
55568
...

~# ./null_syscall
    2546.71 ns     336.17 cycles


With the serie:

~# chrt -f 98 ./context_switch --no-altivec --no-vector --no-fp
55138
55142
55152
55144
55142

~# ./null_syscall
    3479.54 ns     459.30 cycles

So 0,8% less context switches per second and 37% more time for one syscall ?


Any idea ?

Christophe


> 
> Changes since v12:
>   - Patch 1: Taken comment from Mike (re-introduced the 'panic' in case memblock allocation fails in setup_64.c
>   - Patch 1: Added alloc_stack() function in setup_32.c to also panic in case of allocation failure.
> 
> Changes since v11:
>   - Rebased on 81775f5563fa ("Automatic merge of branches 'master', 'next' and 'fixes' into merge")
>   - Added a first patch to change memblock allocs to functions returning virtual addrs. This removes
>     the memset() which were the only remaining stuff in irq_ctx_init() and exc_lvl_ctx_init() at the end.
>   - dropping irq_ctx_init() and exc_lvl_ctx_init() in patch 5 (powerpc: Activate CONFIG_THREAD_INFO_IN_TASK)
>   - A few cosmetic changes in commit log and code.
> 
> Changes since v10:
>   - Rebased on 21622a0d2023 ("Automatic merge of branches 'master', 'next' and 'fixes' into merge")
>    ==> Fixed conflict in setup_32.S
> 
> Changes since v9:
>   - Rebased on 183cbf93be88 ("Automatic merge of branches 'master', 'next' and 'fixes' into merge")
>    ==> Fixed conflict on xmon
> 
> Changes since v8:
>   - Rebased on e589b79e40d9 ("Automatic merge of branches 'master', 'next' and 'fixes' into merge")
>    ==> Main impact was conflicts due to commit 9a8dd708d547 ("memblock: rename memblock_alloc{_nid,_try_nid} to memblock_phys_alloc*")
> 
> Changes since v7:
>   - Rebased on fb6c6ce7907d ("Automatic merge of branches 'master', 'next' and 'fixes' into merge")
> 
> Changes since v6:
>   - Fixed validate_sp() to exclude NULL sp in 'regain entire stack space' patch (early crash with CONFIG_KMEMLEAK)
> 
> Changes since v5:
>   - Fixed livepatch_sp setup by using end_of_stack() instead of hardcoding
>   - Fixed PPC_BPF_LOAD_CPU() macro
> 
> Changes since v4:
>   - Fixed a build failure on 32bits SMP when include/generated/asm-offsets.h is not
>   already existing, was due to spaces instead of a tab in the Makefile
> 
> Changes since RFC v3: (based on Nick's review)
>   - Renamed task_size.h to task_size_user64.h to better relate to what it contains.
>   - Handling of the isolation of thread_info cpu field inside CONFIG_SMP #ifdefs moved to a separate patch.
>   - Removed CURRENT_THREAD_INFO macro completely.
>   - Added a guard in asm/smp.h to avoid build failure before _TASK_CPU is defined.
>   - Added a patch at the end to rename 'tp' pointers to 'sp' pointers
>   - Renamed 'tp' into 'sp' pointers in preparation patch when relevant
>   - Fixed a few commit logs
>   - Fixed checkpatch report.
> 
> Changes since RFC v2:
>   - Removed the modification of names in asm-offsets
>   - Created a rule in arch/powerpc/Makefile to append the offset of current->cpu in CFLAGS
>   - Modified asm/smp.h to use the offset set in CFLAGS
>   - Squashed the renaming of THREAD_INFO to TASK_STACK in the preparation patch
>   - Moved the modification of current_pt_regs in the patch activating CONFIG_THREAD_INFO_IN_TASK
> 
> Changes since RFC v1:
>   - Removed the first patch which was modifying header inclusion order in timer
>   - Modified some names in asm-offsets to avoid conflicts when including asm-offsets in C files
>   - Modified asm/smp.h to avoid having to include linux/sched.h (using asm-offsets instead)
>   - Moved some changes from the activation patch to the preparation patch.
> 
> Christophe Leroy (10):
>    powerpc/irq: use memblock functions returning virtual address
>    book3s/64: avoid circular header inclusion in mmu-hash.h
>    powerpc: Only use task_struct 'cpu' field on SMP
>    powerpc: Prepare for moving thread_info into task_struct
>    powerpc: Activate CONFIG_THREAD_INFO_IN_TASK
>    powerpc: regain entire stack space
>    powerpc: 'current_set' is now a table of task_struct pointers
>    powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU
>    powerpc/64: Remove CURRENT_THREAD_INFO
>    powerpc: clean stack pointers naming
> 
>   arch/powerpc/Kconfig                           |   1 +
>   arch/powerpc/Makefile                          |   7 ++
>   arch/powerpc/include/asm/asm-prototypes.h      |   4 +-
>   arch/powerpc/include/asm/book3s/64/mmu-hash.h  |   2 +-
>   arch/powerpc/include/asm/exception-64s.h       |   4 +-
>   arch/powerpc/include/asm/irq.h                 |  18 ++--
>   arch/powerpc/include/asm/livepatch.h           |   6 +-
>   arch/powerpc/include/asm/processor.h           |  39 +--------
>   arch/powerpc/include/asm/ptrace.h              |   2 +-
>   arch/powerpc/include/asm/reg.h                 |   2 +-
>   arch/powerpc/include/asm/smp.h                 |  17 +++-
>   arch/powerpc/include/asm/task_size_user64.h    |  42 +++++++++
>   arch/powerpc/include/asm/thread_info.h         |  19 -----
>   arch/powerpc/kernel/asm-offsets.c              |  10 ++-
>   arch/powerpc/kernel/entry_32.S                 |  66 +++++---------
>   arch/powerpc/kernel/entry_64.S                 |  12 +--
>   arch/powerpc/kernel/epapr_hcalls.S             |   5 +-
>   arch/powerpc/kernel/exceptions-64e.S           |  13 +--
>   arch/powerpc/kernel/exceptions-64s.S           |   2 +-
>   arch/powerpc/kernel/head_32.S                  |  14 +--
>   arch/powerpc/kernel/head_40x.S                 |   4 +-
>   arch/powerpc/kernel/head_44x.S                 |   8 +-
>   arch/powerpc/kernel/head_64.S                  |   1 +
>   arch/powerpc/kernel/head_8xx.S                 |   2 +-
>   arch/powerpc/kernel/head_booke.h               |  12 +--
>   arch/powerpc/kernel/head_fsl_booke.S           |  16 ++--
>   arch/powerpc/kernel/idle_6xx.S                 |   8 +-
>   arch/powerpc/kernel/idle_book3e.S              |   2 +-
>   arch/powerpc/kernel/idle_e500.S                |   8 +-
>   arch/powerpc/kernel/idle_power4.S              |   2 +-
>   arch/powerpc/kernel/irq.c                      | 114 +++----------------------
>   arch/powerpc/kernel/kgdb.c                     |  28 ------
>   arch/powerpc/kernel/machine_kexec_64.c         |   6 +-
>   arch/powerpc/kernel/misc_32.S                  |  17 ++--
>   arch/powerpc/kernel/process.c                  |  40 ++++-----
>   arch/powerpc/kernel/setup-common.c             |   2 +-
>   arch/powerpc/kernel/setup_32.c                 |  25 +++---
>   arch/powerpc/kernel/setup_64.c                 |  51 +++--------
>   arch/powerpc/kernel/smp.c                      |  16 ++--
>   arch/powerpc/kernel/trace/ftrace_64_mprofile.S |   6 +-
>   arch/powerpc/kvm/book3s_hv_hmi.c               |   1 +
>   arch/powerpc/mm/hash_low_32.S                  |  14 ++-
>   arch/powerpc/net/bpf_jit32.h                   |   5 +-
>   arch/powerpc/sysdev/6xx-suspend.S              |   5 +-
>   arch/powerpc/xmon/xmon.c                       |   2 +-
>   45 files changed, 249 insertions(+), 431 deletions(-)
>   create mode 100644 arch/powerpc/include/asm/task_size_user64.h
> 

^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH v13 00/10] powerpc: Switch to CONFIG_THREAD_INFO_IN_TASK
  2019-01-19 17:21   ` LEROY Christophe
@ 2019-01-23 23:10     ` Michael Ellerman
  0 siblings, 0 replies; 16+ messages in thread
From: Michael Ellerman @ 2019-01-23 23:10 UTC (permalink / raw)
  To: LEROY Christophe
  Cc: linux-kernel, Nicholas Piggin, Mike Rapoport, Paul Mackerras,
	linuxppc-dev

LEROY Christophe <christophe.leroy@c-s.fr> writes:
> Michael Ellerman <mpe@ellerman.id.au> a écrit :
>
>> Christophe Leroy <christophe.leroy@c-s.fr> writes:
>>
>>> The purpose of this serie is to activate CONFIG_THREAD_INFO_IN_TASK which
>>> moves the thread_info into task_struct.
>>>
>>> Moving thread_info into task_struct has the following advantages:
>>> - It protects thread_info from corruption in the case of stack
>>> overflows.
>>> - Its address is harder to determine if stack addresses are
>>> leaked, making a number of attacks more difficult.
>>>
>>> Changes since v12:
>>>  - Patch 1: Taken comment from Mike (re-introduced the 'panic' in  
>>> case memblock allocation fails in setup_64.c
>>>  - Patch 1: Added alloc_stack() function in setup_32.c to also  
>>> panic in case of allocation failure.
>>
>> Hi Christophe,
>>
>> I can't get this series to boot on qemu mac99. I'm getting eg:
>
> Problem new with version 13 or it is the first time you test ?

I did test a previous version of the series, but I'm not sure if I
tested pmac32 before. So I don't have a known good version.

>> [    0.981514] NFS: Registering the id_resolver key type
>> [    0.981752] Key type id_resolver registered
>> [    0.981868] Key type id_legacy registered
>> [    0.995711] Unrecoverable exception 0 at 0 (msr=0)
>> [    0.996091] Oops: Unrecoverable exception, sig: 6 [#1]
>> [    0.996314] BE PAGE_SIZE=4K MMU=Hash PowerMac
>> [    0.996617] Modules linked in:
>> [    0.996869] CPU: 0 PID: 416 Comm: modprobe Not tainted  
>> 5.0.0-rc2-gcc-7.3.0-00043-g53f2de798792 #342
>
> Comm:modprobe  ==> Something wrong with modules ? I never tested with  
> CONFIG_MODULES.

Yep good clue.

cheers

^ permalink raw reply	[flat|nested] 16+ messages in thread

end of thread, back to index

Thread overview: 16+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-01-12  9:55 [PATCH v13 00/10] powerpc: Switch to CONFIG_THREAD_INFO_IN_TASK Christophe Leroy
2019-01-12  9:55 ` [PATCH v13 01/10] powerpc/irq: use memblock functions returning virtual address Christophe Leroy
2019-01-12  9:55 ` [PATCH v13 02/10] book3s/64: avoid circular header inclusion in mmu-hash.h Christophe Leroy
2019-01-12  9:55 ` [PATCH v13 03/10] powerpc: Only use task_struct 'cpu' field on SMP Christophe Leroy
2019-01-12  9:55 ` [PATCH v13 04/10] powerpc: Prepare for moving thread_info into task_struct Christophe Leroy
2019-01-12  9:55 ` [PATCH v13 05/10] powerpc: Activate CONFIG_THREAD_INFO_IN_TASK Christophe Leroy
2019-01-12  9:55 ` [PATCH v13 06/10] powerpc: regain entire stack space Christophe Leroy
2019-01-12  9:55 ` [PATCH v13 07/10] powerpc: 'current_set' is now a table of task_struct pointers Christophe Leroy
2019-01-12  9:55 ` [PATCH v13 08/10] powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU Christophe Leroy
2019-01-12  9:55 ` [PATCH v13 09/10] powerpc/64: Remove CURRENT_THREAD_INFO Christophe Leroy
2019-01-12  9:55 ` [PATCH v13 10/10] powerpc: clean stack pointers naming Christophe Leroy
2019-01-19 10:23 ` [PATCH v13 00/10] powerpc: Switch to CONFIG_THREAD_INFO_IN_TASK Michael Ellerman
2019-01-19 17:21   ` LEROY Christophe
2019-01-23 23:10     ` Michael Ellerman
2019-01-22 19:42   ` Christophe Leroy
2019-01-23 10:04 ` Christophe Leroy

LinuxPPC-Dev Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linuxppc-dev/0 linuxppc-dev/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linuxppc-dev linuxppc-dev/ https://lore.kernel.org/linuxppc-dev \
		linuxppc-dev@lists.ozlabs.org linuxppc-dev@ozlabs.org linuxppc-dev@archiver.kernel.org
	public-inbox-index linuxppc-dev


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.ozlabs.lists.linuxppc-dev


AGPL code for this site: git clone https://public-inbox.org/ public-inbox