[PATCH] mm/pkeys: Remove unused parameter in arch_set_user_pkey_access

From: Jiashuo Liang
Date: Wed Jul 28 2021 - 02:51:54 EST


The arch_set_user_pkey_access function never uses its first parameter
(struct task_struct *tsk). It is only able to set the pkey permissions for
the current task as implemented, and existing kernel code only passes
"current" to arch_set_user_pkey_access. So remove the ambiguous parameter
to make the code clean.

Signed-off-by: Jiashuo Liang <liangjs@xxxxxxxxxx>
---
arch/powerpc/include/asm/pkeys.h | 8 +++-----
arch/powerpc/mm/book3s64/pkeys.c | 3 +--
arch/x86/include/asm/pkeys.h | 12 ++++--------
arch/x86/kernel/fpu/xstate.c | 3 +--
arch/x86/mm/pkeys.c | 3 +--
include/linux/pkeys.h | 3 +--
mm/mprotect.c | 2 +-
7 files changed, 12 insertions(+), 22 deletions(-)

diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h
index 59a2c7dbc78f..e905b2ab31e2 100644
--- a/arch/powerpc/include/asm/pkeys.h
+++ b/arch/powerpc/include/asm/pkeys.h
@@ -143,10 +143,8 @@ static inline int arch_override_mprotect_pkey(struct vm_area_struct *vma,
return __arch_override_mprotect_pkey(vma, prot, pkey);
}

-extern int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
- unsigned long init_val);
-static inline int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
- unsigned long init_val)
+extern int __arch_set_user_pkey_access(int pkey, unsigned long init_val);
+static inline int arch_set_user_pkey_access(int pkey, unsigned long init_val)
{
if (!mmu_has_feature(MMU_FTR_PKEY))
return -EINVAL;
@@ -160,7 +158,7 @@ static inline int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
if (pkey == 0)
return init_val ? -EINVAL : 0;

- return __arch_set_user_pkey_access(tsk, pkey, init_val);
+ return __arch_set_user_pkey_access(pkey, init_val);
}

static inline bool arch_pkeys_enabled(void)
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index a2d9ad138709..dc77c0a27291 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -333,8 +333,7 @@ static inline void init_iamr(int pkey, u8 init_bits)
* Set the access rights in AMR IAMR and UAMOR registers for @pkey to that
* specified in @init_val.
*/
-int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
- unsigned long init_val)
+int __arch_set_user_pkey_access(int pkey, unsigned long init_val)
{
u64 new_amr_bits = 0x0ul;
u64 new_iamr_bits = 0x0ul;
diff --git a/arch/x86/include/asm/pkeys.h b/arch/x86/include/asm/pkeys.h
index 5c7bcaa79623..26d872bdee49 100644
--- a/arch/x86/include/asm/pkeys.h
+++ b/arch/x86/include/asm/pkeys.h
@@ -11,8 +11,7 @@
*/
#define arch_max_pkey() (cpu_feature_enabled(X86_FEATURE_OSPKE) ? 16 : 1)

-extern int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
- unsigned long init_val);
+extern int arch_set_user_pkey_access(int pkey, unsigned long init_val);

static inline bool arch_pkeys_enabled(void)
{
@@ -43,8 +42,7 @@ static inline int arch_override_mprotect_pkey(struct vm_area_struct *vma,
return __arch_override_mprotect_pkey(vma, prot, pkey);
}

-extern int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
- unsigned long init_val);
+extern int __arch_set_user_pkey_access(int pkey, unsigned long init_val);

#define ARCH_VM_PKEY_FLAGS (VM_PKEY_BIT0 | VM_PKEY_BIT1 | VM_PKEY_BIT2 | VM_PKEY_BIT3)

@@ -120,10 +118,8 @@ int mm_pkey_free(struct mm_struct *mm, int pkey)
return 0;
}

-extern int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
- unsigned long init_val);
-extern int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
- unsigned long init_val);
+extern int arch_set_user_pkey_access(int pkey, unsigned long init_val);
+extern int __arch_set_user_pkey_access(int pkey, unsigned long init_val);

static inline int vma_pkey(struct vm_area_struct *vma)
{
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index c8def1b7f8fb..565de4a49c0a 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -912,8 +912,7 @@ EXPORT_SYMBOL_GPL(get_xsave_addr);
* This will go out and modify PKRU register to set the access
* rights for @pkey to @init_val.
*/
-int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
- unsigned long init_val)
+int arch_set_user_pkey_access(int pkey, unsigned long init_val)
{
u32 old_pkru, new_pkru_bits = 0;
int pkey_shift;
diff --git a/arch/x86/mm/pkeys.c b/arch/x86/mm/pkeys.c
index e44e938885b7..fafc10ea7cf1 100644
--- a/arch/x86/mm/pkeys.c
+++ b/arch/x86/mm/pkeys.c
@@ -42,8 +42,7 @@ int __execute_only_pkey(struct mm_struct *mm)
* Set up PKRU so that it denies access for everything
* other than execution.
*/
- ret = arch_set_user_pkey_access(current, execute_only_pkey,
- PKEY_DISABLE_ACCESS);
+ ret = arch_set_user_pkey_access(execute_only_pkey, PKEY_DISABLE_ACCESS);
/*
* If the PKRU-set operation failed somehow, just return
* 0 and effectively disable execute-only support.
diff --git a/include/linux/pkeys.h b/include/linux/pkeys.h
index 6beb26b7151d..c8a5d96ab461 100644
--- a/include/linux/pkeys.h
+++ b/include/linux/pkeys.h
@@ -33,8 +33,7 @@ static inline int mm_pkey_free(struct mm_struct *mm, int pkey)
return -EINVAL;
}

-static inline int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
- unsigned long init_val)
+static inline int arch_set_user_pkey_access(int pkey, unsigned long init_val)
{
return 0;
}
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 883e2cc85cad..fe2c4755d833 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -689,7 +689,7 @@ SYSCALL_DEFINE2(pkey_alloc, unsigned long, flags, unsigned long, init_val)
if (pkey == -1)
goto out;

- ret = arch_set_user_pkey_access(current, pkey, init_val);
+ ret = arch_set_user_pkey_access(pkey, init_val);
if (ret) {
mm_pkey_free(current->mm, pkey);
goto out;
--
2.32.0