diff options
| author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2023-07-11 17:59:14 +0200 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2023-08-02 22:22:17 +1000 |
| commit | 1bec4adcd59e923df6b7f5d492a9e4b8dfd22039 (patch) | |
| tree | eaa22f62573f89b0c76dfd681ff487034a6ab766 /arch/powerpc/include/asm/nohash | |
| parent | 880df2d46a3f23f30f954f6e64c576d7f411cc46 (diff) | |
powerpc/kuap: Avoid useless jump_label on empty function
Disassembly of interrupt_enter_prepare() shows a pointless nop
before the mftb
c000abf0 <interrupt_enter_prepare>:
c000abf0: 81 23 00 84 lwz r9,132(r3)
c000abf4: 71 29 40 00 andi. r9,r9,16384
c000abf8: 41 82 00 28 beq- c000ac20 <interrupt_enter_prepare+0x30>
c000abfc: ===> 60 00 00 00 nop <====
c000ac00: 7d 0c 42 e6 mftb r8
c000ac04: 80 e2 00 08 lwz r7,8(r2)
c000ac08: 81 22 00 28 lwz r9,40(r2)
c000ac0c: 91 02 00 24 stw r8,36(r2)
c000ac10: 7d 29 38 50 subf r9,r9,r7
c000ac14: 7d 29 42 14 add r9,r9,r8
c000ac18: 91 22 00 08 stw r9,8(r2)
c000ac1c: 4e 80 00 20 blr
c000ac20: 60 00 00 00 nop
c000ac24: 7d 5a c2 a6 mfmd_ap r10
c000ac28: 3d 20 de 00 lis r9,-8704
c000ac2c: 91 43 00 b0 stw r10,176(r3)
c000ac30: 7d 3a c3 a6 mtspr 794,r9
c000ac34: 4e 80 00 20 blr
That comes from the call to kuap_loc(), allthough __kuap_lock() is an
empty function on the 8xx.
To avoid that, only perform kuap_is_disabled() check when there is
something to do with __kuap_lock().
Do the same with __kuap_save_and_lock() and
__kuap_get_and_assert_locked().
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/a854d25bea375d4ba6ca9c2617f9edbba397100a.1689091022.git.christophe.leroy@csgroup.eu
Diffstat (limited to 'arch/powerpc/include/asm/nohash')
| -rw-r--r-- | arch/powerpc/include/asm/nohash/32/kup-8xx.h | 11 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/nohash/kup-booke.h | 8 |
2 files changed, 11 insertions, 8 deletions
diff --git a/arch/powerpc/include/asm/nohash/32/kup-8xx.h b/arch/powerpc/include/asm/nohash/32/kup-8xx.h index 8579210f2a6a..a372cd822887 100644 --- a/arch/powerpc/include/asm/nohash/32/kup-8xx.h +++ b/arch/powerpc/include/asm/nohash/32/kup-8xx.h @@ -20,15 +20,12 @@ static __always_inline bool kuap_is_disabled(void) return static_branch_unlikely(&disable_kuap_key); } -static inline void __kuap_lock(void) -{ -} - static inline void __kuap_save_and_lock(struct pt_regs *regs) { regs->kuap = mfspr(SPRN_MD_AP); mtspr(SPRN_MD_AP, MD_APG_KUAP); } +#define __kuap_save_and_lock __kuap_save_and_lock static inline void kuap_user_restore(struct pt_regs *regs) { @@ -39,13 +36,15 @@ static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kua mtspr(SPRN_MD_AP, regs->kuap); } +#ifdef CONFIG_PPC_KUAP_DEBUG static inline unsigned long __kuap_get_and_assert_locked(void) { - if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG)) - WARN_ON_ONCE(mfspr(SPRN_MD_AP) >> 16 != MD_APG_KUAP >> 16); + WARN_ON_ONCE(mfspr(SPRN_MD_AP) >> 16 != MD_APG_KUAP >> 16); return 0; } +#define __kuap_get_and_assert_locked __kuap_get_and_assert_locked +#endif static inline void __allow_user_access(void __user *to, const void __user *from, unsigned long size, unsigned long dir) diff --git a/arch/powerpc/include/asm/nohash/kup-booke.h b/arch/powerpc/include/asm/nohash/kup-booke.h index 823c5a3a96d8..71182cbe20c3 100644 --- a/arch/powerpc/include/asm/nohash/kup-booke.h +++ b/arch/powerpc/include/asm/nohash/kup-booke.h @@ -30,6 +30,7 @@ static inline void __kuap_lock(void) mtspr(SPRN_PID, 0); isync(); } +#define __kuap_lock __kuap_lock static inline void __kuap_save_and_lock(struct pt_regs *regs) { @@ -37,6 +38,7 @@ static inline void __kuap_save_and_lock(struct pt_regs *regs) mtspr(SPRN_PID, 0); isync(); } +#define __kuap_save_and_lock __kuap_save_and_lock static inline void kuap_user_restore(struct pt_regs *regs) { @@ -56,13 +58,15 @@ static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kua /* Context synchronisation is performed by rfi */ } +#ifdef CONFIG_PPC_KUAP_DEBUG static inline unsigned long __kuap_get_and_assert_locked(void) { - if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG)) - WARN_ON_ONCE(mfspr(SPRN_PID)); + WARN_ON_ONCE(mfspr(SPRN_PID)); return 0; } +#define __kuap_get_and_assert_locked __kuap_get_and_assert_locked +#endif static inline void __allow_user_access(void __user *to, const void __user *from, unsigned long size, unsigned long dir) |