From: ira.weiny@intel.com
To: Dave Hansen <dave.hansen@linux.intel.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Dan Williams <dan.j.williams@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>,
Fenghua Yu <fenghua.yu@intel.com>,
Rick Edgecombe <rick.p.edgecombe@intel.com>,
"Shankar, Ravi V" <ravi.v.shankar@intel.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH V10 04/44] x86/fpu: Refactor arch_set_user_pkey_access()
Date: Tue, 19 Apr 2022 10:06:09 -0700 [thread overview]
Message-ID: <20220419170649.1022246-5-ira.weiny@intel.com> (raw)
In-Reply-To: <20220419170649.1022246-1-ira.weiny@intel.com>
From: Ira Weiny <ira.weiny@intel.com>
Both PKU and PKS update their register values in the same way. They can
therefore share the update code.
Define a helper, pkey_update_pkval(), which will be used to support both
Protection Key User (PKU) and the new Protection Key for Supervisor
(PKS) in subsequent patches.
pkey_update_pkval() contributed by Thomas
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Co-developed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
Update for V8:
From Rick Edgecombe
Change pkey type to u8
Replace the code Peter provided in update_pkey_reg() for
Thomas' pkey_update_pkval()
-- https://lore.kernel.org/lkml/20200717085442.GX10769@hirez.programming.kicks-ass.net/
---
arch/x86/include/asm/pkeys.h | 2 ++
arch/x86/kernel/fpu/xstate.c | 22 ++++------------------
arch/x86/mm/pkeys.c | 16 ++++++++++++++++
3 files changed, 22 insertions(+), 18 deletions(-)
diff --git a/arch/x86/include/asm/pkeys.h b/arch/x86/include/asm/pkeys.h
index 1d5f14aff5f6..26616cbe19e2 100644
--- a/arch/x86/include/asm/pkeys.h
+++ b/arch/x86/include/asm/pkeys.h
@@ -131,4 +131,6 @@ static inline int vma_pkey(struct vm_area_struct *vma)
return (vma->vm_flags & vma_pkey_mask) >> VM_PKEY_SHIFT;
}
+u32 pkey_update_pkval(u32 pkval, u8 pkey, u32 accessbits);
+
#endif /*_ASM_X86_PKEYS_H */
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index e525bfee7e07..ea9207b12863 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -984,8 +984,7 @@ void *get_xsave_addr(struct xregs_state *xsave, int xfeature_nr)
int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
unsigned long init_val)
{
- u32 old_pkru, new_pkru_bits = 0;
- int pkey_shift;
+ u32 pkru;
/*
* This check implies XSAVE support. OSPKE only gets
@@ -1002,22 +1001,9 @@ int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
if (WARN_ON_ONCE(pkey >= arch_max_pkey()))
return -EINVAL;
- /* Set the bits needed in PKRU: */
- if (init_val & PKEY_DISABLE_ACCESS)
- new_pkru_bits |= PKR_AD_BIT;
- if (init_val & PKEY_DISABLE_WRITE)
- new_pkru_bits |= PKR_WD_BIT;
-
- /* Shift the bits in to the correct place in PKRU for pkey: */
- pkey_shift = pkey * PKR_BITS_PER_PKEY;
- new_pkru_bits <<= pkey_shift;
-
- /* Get old PKRU and mask off any old bits in place: */
- old_pkru = read_pkru();
- old_pkru &= ~((PKR_AD_BIT|PKR_WD_BIT) << pkey_shift);
-
- /* Write old part along with new part: */
- write_pkru(old_pkru | new_pkru_bits);
+ pkru = read_pkru();
+ pkru = pkey_update_pkval(pkru, pkey, init_val);
+ write_pkru(pkru);
return 0;
}
diff --git a/arch/x86/mm/pkeys.c b/arch/x86/mm/pkeys.c
index e1527b4619e1..7c90b2188c5f 100644
--- a/arch/x86/mm/pkeys.c
+++ b/arch/x86/mm/pkeys.c
@@ -193,3 +193,19 @@ static __init int setup_init_pkru(char *opt)
return 1;
}
__setup("init_pkru=", setup_init_pkru);
+
+/*
+ * Kernel users use the same flags as user space:
+ * PKEY_DISABLE_ACCESS
+ * PKEY_DISABLE_WRITE
+ */
+u32 pkey_update_pkval(u32 pkval, u8 pkey, u32 accessbits)
+{
+ int shift = pkey * PKR_BITS_PER_PKEY;
+
+ if (WARN_ON_ONCE(accessbits & ~PKEY_ACCESS_MASK))
+ accessbits &= PKEY_ACCESS_MASK;
+
+ pkval &= ~(PKEY_ACCESS_MASK << shift);
+ return pkval | accessbits << shift;
+}
--
2.35.1
next prev parent reply other threads:[~2022-04-19 17:07 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-19 17:06 [PATCH V10 00/44] PKS/PMEM: Add Stray Write Protection ira.weiny
2022-04-19 17:06 ` [PATCH V10 01/44] Documentation/protection-keys: Clean up documentation for User Space pkeys ira.weiny
2022-06-07 23:09 ` [tip: x86/mm] " tip-bot2 for Ira Weiny
2022-04-19 17:06 ` [PATCH V10 02/44] x86/pkeys: Clarify PKRU_AD_KEY macro ira.weiny
2022-06-07 23:09 ` [tip: x86/mm] " tip-bot2 for Ira Weiny
2022-04-19 17:06 ` [PATCH V10 03/44] x86/pkeys: Make PKRU macros generic ira.weiny
2022-04-19 17:06 ` ira.weiny [this message]
2022-04-19 17:06 ` [PATCH V10 05/44] mm/pkeys: Add Kconfig options for PKS ira.weiny
2022-04-19 17:06 ` [PATCH V10 06/44] x86/pkeys: Add PKS CPU feature bit ira.weiny
2022-04-19 17:06 ` [PATCH V10 07/44] x86/fault: Adjust WARN_ON for pkey fault ira.weiny
2022-04-19 17:06 ` [PATCH V10 08/44] Documentation/pkeys: Add initial PKS documentation ira.weiny
2022-05-09 22:03 ` Kees Cook
2022-05-10 17:18 ` Ira Weiny
2022-05-10 20:17 ` Kees Cook
2022-04-19 17:06 ` [PATCH V10 09/44] mm/pkeys: Provide for PKS key allocation ira.weiny
2022-04-19 17:06 ` [PATCH V10 10/44] x86/pkeys: Enable PKS on cpus which support it ira.weiny
2022-04-19 17:06 ` [PATCH V10 11/44] mm/pkeys: Define PKS page table macros ira.weiny
2022-04-19 17:06 ` [PATCH V10 12/44] x86/pkeys: Introduce pks_write_pkrs() ira.weiny
2022-04-19 17:06 ` [PATCH V10 13/44] x86/pkeys: Preserve the PKS MSR on context switch ira.weiny
2022-04-19 17:06 ` [PATCH V10 14/44] mm/pkeys: Introduce pks_set_readwrite() ira.weiny
2022-05-09 21:38 ` Kees Cook
2022-05-10 21:33 ` Ira Weiny
2022-05-10 22:08 ` Kees Cook
2022-05-10 22:26 ` Edgecombe, Rick P
2022-05-11 3:15 ` Kees Cook
2022-05-11 17:59 ` Ira Weiny
2022-04-19 17:06 ` [PATCH V10 15/44] mm/pkeys: Introduce pks_set_noaccess() ira.weiny
2022-04-19 17:06 ` [PATCH V10 16/44] mm/pkeys: Introduce PKS fault callbacks ira.weiny
2022-04-19 17:06 ` [PATCH V10 17/44] x86/entry: Add auxiliary pt_regs space ira.weiny
2022-04-19 17:06 ` [PATCH V10 18/44] entry: Pass pt_regs to irqentry_exit_cond_resched() ira.weiny
2022-04-19 17:06 ` [PATCH V10 19/44] entry: Add calls for save/restore auxiliary pt_regs ira.weiny
2022-04-19 17:06 ` [PATCH V10 20/44] x86/entry: Define arch_{save|restore}_auxiliary_pt_regs() ira.weiny
2022-04-19 17:06 ` [PATCH V10 21/44] x86/pkeys: Preserve PKRS MSR across exceptions ira.weiny
2022-04-19 17:06 ` [PATCH V10 22/44] x86/fault: Print PKS MSR on fault ira.weiny
2022-04-19 17:06 ` [PATCH V10 23/44] mm/pkeys: Introduce pks_update_exception() ira.weiny
2022-04-19 17:06 ` [PATCH V10 24/44] mm/pkeys: Add pks_available() ira.weiny
2022-04-19 17:06 ` [PATCH V10 25/44] memremap_pages: Add Kconfig for DEVMAP_ACCESS_PROTECTION ira.weiny
2022-04-19 17:06 ` [PATCH V10 26/44] memremap_pages: Introduce pgmap_protection_available() ira.weiny
2022-04-19 17:06 ` [PATCH V10 27/44] memremap_pages: Introduce a PGMAP_PROTECTION flag ira.weiny
2022-04-19 17:06 ` [PATCH V10 28/44] memremap_pages: Introduce devmap_protected() ira.weiny
2022-04-19 17:06 ` [PATCH V10 29/44] memremap_pages: Reserve a PKS pkey for eventual use by PMEM ira.weiny
2022-04-19 17:06 ` [PATCH V10 30/44] memremap_pages: Set PKS pkey in PTEs if requested ira.weiny
2022-04-19 17:06 ` [PATCH V10 31/44] memremap_pages: Define pgmap_set_{readwrite|noaccess}() calls ira.weiny
2022-04-19 17:06 ` [PATCH V10 32/44] memremap_pages: Add memremap.pks_fault_mode ira.weiny
2022-04-19 17:06 ` [PATCH V10 33/44] kmap: Make kmap work for devmap protected pages ira.weiny
2022-04-28 15:50 ` Christoph Hellwig
2022-05-12 1:25 ` Ira Weiny
2022-05-17 22:46 ` Ira Weiny
2022-05-18 7:33 ` Christoph Hellwig
2022-05-19 20:29 ` Ira Weiny
2022-04-19 17:06 ` [PATCH V10 34/44] dax: Stray access protection for dax_direct_access() ira.weiny
2022-04-19 17:06 ` [PATCH V10 35/44] nvdimm/pmem: Enable stray access protection ira.weiny
2022-04-19 17:06 ` [PATCH V10 36/44] devdax: " ira.weiny
2022-04-19 17:06 ` [PATCH V10 37/44] mm/pkeys: PKS testing, add initial test code ira.weiny
2022-04-19 17:06 ` [PATCH V10 38/44] x86/selftests: Add test_pks ira.weiny
2022-04-19 17:06 ` [PATCH V10 39/44] mm/pkeys: PKS testing, add a fault call back ira.weiny
2022-04-19 17:06 ` [PATCH V10 40/44] mm/pkeys: PKS testing, add pks_set_*() tests ira.weiny
2022-04-19 17:06 ` [PATCH V10 41/44] mm/pkeys: PKS testing, test context switching ira.weiny
2022-04-19 17:06 ` [PATCH V10 42/44] mm/pkeys: PKS testing, Add exception test ira.weiny
2022-04-19 17:06 ` [PATCH V10 43/44] mm/pkeys: PKS testing, test pks_update_exception() ira.weiny
2022-04-19 17:06 ` [PATCH V10 44/44] mm/pkeys: PKS testing, add test for all keys ira.weiny
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