diff options
Diffstat (limited to 'arch/powerpc/include/asm/book3s/64/kup-radix.h')
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/kup-radix.h | 41 |
1 files changed, 35 insertions, 6 deletions
diff --git a/arch/powerpc/include/asm/book3s/64/kup-radix.h b/arch/powerpc/include/asm/book3s/64/kup-radix.h index 3bcef989a35d..3ee1ec60be84 100644 --- a/arch/powerpc/include/asm/book3s/64/kup-radix.h +++ b/arch/powerpc/include/asm/book3s/64/kup-radix.h @@ -12,11 +12,17 @@ #ifdef __ASSEMBLY__ -.macro kuap_restore_amr gpr +.macro kuap_restore_amr gpr1, gpr2 #ifdef CONFIG_PPC_KUAP BEGIN_MMU_FTR_SECTION_NESTED(67) - ld \gpr, STACK_REGS_KUAP(r1) - mtspr SPRN_AMR, \gpr + mfspr \gpr1, SPRN_AMR + ld \gpr2, STACK_REGS_KUAP(r1) + cmpd \gpr1, \gpr2 + beq 998f + isync + mtspr SPRN_AMR, \gpr2 + /* No isync required, see kuap_restore_amr() */ +998: END_MMU_FTR_SECTION_NESTED_IFSET(MMU_FTR_RADIX_KUAP, 67) #endif .endm @@ -60,10 +66,28 @@ #include <asm/mmu.h> #include <asm/ptrace.h> -static inline void kuap_restore_amr(struct pt_regs *regs) +static inline void kuap_restore_amr(struct pt_regs *regs, unsigned long amr) { - if (mmu_has_feature(MMU_FTR_RADIX_KUAP)) + if (mmu_has_feature(MMU_FTR_RADIX_KUAP) && unlikely(regs->kuap != amr)) { + isync(); mtspr(SPRN_AMR, regs->kuap); + /* + * No isync required here because we are about to RFI back to + * previous context before any user accesses would be made, + * which is a CSI. + */ + } +} + +static inline unsigned long kuap_get_and_check_amr(void) +{ + if (mmu_has_feature(MMU_FTR_RADIX_KUAP)) { + unsigned long amr = mfspr(SPRN_AMR); + if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG)) /* kuap_check_amr() */ + WARN_ON_ONCE(amr != AMR_KUAP_BLOCKED); + return amr; + } + return 0; } static inline void kuap_check_amr(void) @@ -142,13 +166,18 @@ bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write) "Bug: %s fault blocked by AMR!", is_write ? "Write" : "Read"); } #else /* CONFIG_PPC_KUAP */ -static inline void kuap_restore_amr(struct pt_regs *regs) +static inline void kuap_restore_amr(struct pt_regs *regs, unsigned long amr) { } static inline void kuap_check_amr(void) { } + +static inline unsigned long kuap_get_and_check_amr(void) +{ + return 0; +} #endif /* CONFIG_PPC_KUAP */ #endif /* __ASSEMBLY__ */ |