summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/mm
diff options
context:
space:
mode:
authorAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>2020-11-27 05:44:16 +0100
committerMichael Ellerman <mpe@ellerman.id.au>2020-12-03 15:01:26 +0100
commit48a8ab4eeb8271f2a0e2ca3cf80844a59acca153 (patch)
treeec0ff290cbe68d27cdb8d46c4f489405fbf3db6f /arch/powerpc/mm
parentpowerpc/ptrace-view: Use pt_regs values instead of thread_struct based one. (diff)
downloadlinux-48a8ab4eeb8271f2a0e2ca3cf80844a59acca153.tar.xz
linux-48a8ab4eeb8271f2a0e2ca3cf80844a59acca153.zip
powerpc/book3s64/pkeys: Don't update SPRN_AMR when in kernel mode.
Now that kernel correctly store/restore userspace AMR/IAMR values, avoid manipulating AMR and IAMR from the kernel on behalf of userspace. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: Sandipan Das <sandipan@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201127044424.40686-15-aneesh.kumar@linux.ibm.com
Diffstat (limited to 'arch/powerpc/mm')
-rw-r--r--arch/powerpc/mm/book3s64/pkeys.c57
1 files changed, 10 insertions, 47 deletions
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index 355d001fa155..8d1bf2f18ca4 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -281,30 +281,17 @@ void __init setup_kuap(bool disabled)
}
#endif
-static inline u64 read_amr(void)
+static inline void update_current_thread_amr(u64 value)
{
- return mfspr(SPRN_AMR);
+ current->thread.regs->amr = value;
}
-static inline void write_amr(u64 value)
-{
- mtspr(SPRN_AMR, value);
-}
-
-static inline u64 read_iamr(void)
-{
- if (!likely(pkey_execute_disable_supported))
- return 0x0UL;
-
- return mfspr(SPRN_IAMR);
-}
-
-static inline void write_iamr(u64 value)
+static inline void update_current_thread_iamr(u64 value)
{
if (!likely(pkey_execute_disable_supported))
return;
- mtspr(SPRN_IAMR, value);
+ current->thread.regs->iamr = value;
}
#ifdef CONFIG_PPC_MEM_KEYS
@@ -319,17 +306,17 @@ void pkey_mm_init(struct mm_struct *mm)
static inline void init_amr(int pkey, u8 init_bits)
{
u64 new_amr_bits = (((u64)init_bits & 0x3UL) << pkeyshift(pkey));
- u64 old_amr = read_amr() & ~((u64)(0x3ul) << pkeyshift(pkey));
+ u64 old_amr = current_thread_amr() & ~((u64)(0x3ul) << pkeyshift(pkey));
- write_amr(old_amr | new_amr_bits);
+ update_current_thread_amr(old_amr | new_amr_bits);
}
static inline void init_iamr(int pkey, u8 init_bits)
{
u64 new_iamr_bits = (((u64)init_bits & 0x1UL) << pkeyshift(pkey));
- u64 old_iamr = read_iamr() & ~((u64)(0x1ul) << pkeyshift(pkey));
+ u64 old_iamr = current_thread_iamr() & ~((u64)(0x1ul) << pkeyshift(pkey));
- write_iamr(old_iamr | new_iamr_bits);
+ update_current_thread_iamr(old_iamr | new_iamr_bits);
}
/*
@@ -372,30 +359,6 @@ int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
return 0;
}
-void thread_pkey_regs_save(struct thread_struct *thread)
-{
- if (!mmu_has_feature(MMU_FTR_PKEY))
- return;
-
- /*
- * TODO: Skip saving registers if @thread hasn't used any keys yet.
- */
- thread->amr = read_amr();
- thread->iamr = read_iamr();
-}
-
-void thread_pkey_regs_restore(struct thread_struct *new_thread,
- struct thread_struct *old_thread)
-{
- if (!mmu_has_feature(MMU_FTR_PKEY))
- return;
-
- if (old_thread->amr != new_thread->amr)
- write_amr(new_thread->amr);
- if (old_thread->iamr != new_thread->iamr)
- write_iamr(new_thread->iamr);
-}
-
int execute_only_pkey(struct mm_struct *mm)
{
return mm->context.execute_only_pkey;
@@ -444,9 +407,9 @@ static bool pkey_access_permitted(int pkey, bool write, bool execute)
pkey_shift = pkeyshift(pkey);
if (execute)
- return !(read_iamr() & (IAMR_EX_BIT << pkey_shift));
+ return !(current_thread_iamr() & (IAMR_EX_BIT << pkey_shift));
- amr = read_amr();
+ amr = current_thread_amr();
if (write)
return !(amr & (AMR_WR_BIT << pkey_shift));