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| author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2021-06-03 08:41:37 +0000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-06-17 00:09:07 +1000 |
| commit | 91bb30822a2e1d7900f9f42e9e92647a9015f979 (patch) | |
| tree | 65b175ba7614d99c0cfe3a49a1f4504cca0d7e4a /arch/powerpc/include/asm/book3s/32 | |
| parent | 91ec66719d4c5c0e7b4e32585b01881660d1bc53 (diff) | |
| download | linux-stable-91bb30822a2e1d7900f9f42e9e92647a9015f979.tar.gz linux-stable-91bb30822a2e1d7900f9f42e9e92647a9015f979.tar.bz2 linux-stable-91bb30822a2e1d7900f9f42e9e92647a9015f979.zip | |
powerpc/32s: Refactor update of user segment registers
KUEP implements the update of user segment registers.
Move it into mmu-hash.h in order to use it from other places.
And inline kuep_lock() and kuep_unlock(). Inlining kuep_lock() is
important for system_call_exception(), otherwise system_call_exception()
has to save into stack the system call parameters that are used just
after, and doing that takes more instructions than kuep_lock() itself.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/24591ca480d14a62ef910e38a5273d551262c4a2.1622708530.git.christophe.leroy@csgroup.eu
Diffstat (limited to 'arch/powerpc/include/asm/book3s/32')
| -rw-r--r-- | arch/powerpc/include/asm/book3s/32/kup.h | 21 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/book3s/32/mmu-hash.h | 27 |
2 files changed, 48 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h index c1f7c2e625a6..83aa0dde50d6 100644 --- a/arch/powerpc/include/asm/book3s/32/kup.h +++ b/arch/powerpc/include/asm/book3s/32/kup.h @@ -7,6 +7,27 @@ #ifndef __ASSEMBLY__ +static __always_inline bool kuep_is_disabled(void) +{ + return !IS_ENABLED(CONFIG_PPC_KUEP); +} + +static inline void kuep_lock(void) +{ + if (kuep_is_disabled()) + return; + + update_user_segments(mfsr(0) | SR_NX); +} + +static inline void kuep_unlock(void) +{ + if (kuep_is_disabled()) + return; + + update_user_segments(mfsr(0) & ~SR_NX); +} + #ifdef CONFIG_PPC_KUAP #include <linux/sched.h> diff --git a/arch/powerpc/include/asm/book3s/32/mmu-hash.h b/arch/powerpc/include/asm/book3s/32/mmu-hash.h index b85f8e114a9c..cc0284bbac86 100644 --- a/arch/powerpc/include/asm/book3s/32/mmu-hash.h +++ b/arch/powerpc/include/asm/book3s/32/mmu-hash.h @@ -102,6 +102,33 @@ extern s32 patch__hash_page_B, patch__hash_page_C; extern s32 patch__flush_hash_A0, patch__flush_hash_A1, patch__flush_hash_A2; extern s32 patch__flush_hash_B; +#include <asm/reg.h> +#include <asm/task_size_32.h> + +#define UPDATE_TWO_USER_SEGMENTS(n) do { \ + if (TASK_SIZE > ((n) << 28)) \ + mtsr(val1, (n) << 28); \ + if (TASK_SIZE > (((n) + 1) << 28)) \ + mtsr(val2, ((n) + 1) << 28); \ + val1 = (val1 + 0x222) & 0xf0ffffff; \ + val2 = (val2 + 0x222) & 0xf0ffffff; \ +} while (0) + +static __always_inline void update_user_segments(u32 val) +{ + int val1 = val; + int val2 = (val + 0x111) & 0xf0ffffff; + + UPDATE_TWO_USER_SEGMENTS(0); + UPDATE_TWO_USER_SEGMENTS(2); + UPDATE_TWO_USER_SEGMENTS(4); + UPDATE_TWO_USER_SEGMENTS(6); + UPDATE_TWO_USER_SEGMENTS(8); + UPDATE_TWO_USER_SEGMENTS(10); + UPDATE_TWO_USER_SEGMENTS(12); + UPDATE_TWO_USER_SEGMENTS(14); +} + #endif /* !__ASSEMBLY__ */ /* We happily ignore the smaller BATs on 601, we don't actually use |