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| author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2020-12-09 06:29:23 +0100 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-12-09 13:48:13 +0100 |
| commit | 3dc12dfe74300febc568c3b530c0f9bee01f2821 (patch) | |
| tree | 42783ff7861836cf359ab4d83181cb01da5fce72 | |
| parent | powerpc/fault: Unnest definition of page_fault_is_write() and page_fault_is_b... (diff) | |
| download | linux-3dc12dfe74300febc568c3b530c0f9bee01f2821.tar.xz linux-3dc12dfe74300febc568c3b530c0f9bee01f2821.zip | |
powerpc/mm: Move the WARN() out of bad_kuap_fault()
In order to prepare the removal of calls to
search_exception_tables() on the fast path, move the
WARN() out of bad_kuap_fault().
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/9501311014bd6507e04b27a0c3035186ccf65cd5.1607491748.git.christophe.leroy@csgroup.eu
| -rw-r--r-- | arch/powerpc/include/asm/book3s/32/kup.h | 6 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/kup.h | 6 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/nohash/32/kup-8xx.h | 3 | ||||
| -rw-r--r-- | arch/powerpc/mm/fault.c | 2 |
4 files changed, 5 insertions, 12 deletions
diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h index 32fd4452e960..a0117a9d5b06 100644 --- a/arch/powerpc/include/asm/book3s/32/kup.h +++ b/arch/powerpc/include/asm/book3s/32/kup.h @@ -183,11 +183,7 @@ bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write) unsigned long begin = regs->kuap & 0xf0000000; unsigned long end = regs->kuap << 28; - if (!is_write) - return false; - - return WARN(address < begin || address >= end, - "Bug: write fault blocked by segment registers !"); + return is_write && (address < begin || address >= end); } #endif /* CONFIG_PPC_KUAP */ diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h index 7075c92c320c..f50f72e535aa 100644 --- a/arch/powerpc/include/asm/book3s/64/kup.h +++ b/arch/powerpc/include/asm/book3s/64/kup.h @@ -371,11 +371,9 @@ static inline bool bad_kuap_fault(struct pt_regs *regs, unsigned long address, * the AMR. Hence check for BLOCK_WRITE/READ against AMR. */ if (is_write) { - return WARN(((regs->amr & AMR_KUAP_BLOCK_WRITE) == AMR_KUAP_BLOCK_WRITE), - "Bug: Write fault blocked by AMR!"); + return (regs->amr & AMR_KUAP_BLOCK_WRITE) == AMR_KUAP_BLOCK_WRITE; } - return WARN(((regs->amr & AMR_KUAP_BLOCK_READ) == AMR_KUAP_BLOCK_READ), - "Bug: Read fault blocked by AMR!"); + return (regs->amr & AMR_KUAP_BLOCK_READ) == AMR_KUAP_BLOCK_READ; } static __always_inline void allow_user_access(void __user *to, const void __user *from, diff --git a/arch/powerpc/include/asm/nohash/32/kup-8xx.h b/arch/powerpc/include/asm/nohash/32/kup-8xx.h index 567cdc557402..17a4a616436f 100644 --- a/arch/powerpc/include/asm/nohash/32/kup-8xx.h +++ b/arch/powerpc/include/asm/nohash/32/kup-8xx.h @@ -63,8 +63,7 @@ static inline void restore_user_access(unsigned long flags) static inline bool bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write) { - return WARN(!((regs->kuap ^ MD_APG_KUAP) & 0xff000000), - "Bug: fault blocked by AP register !"); + return !((regs->kuap ^ MD_APG_KUAP) & 0xff000000); } #endif /* !__ASSEMBLY__ */ diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index 3fcd34c28e10..04505f938bbc 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -228,7 +228,7 @@ static bool bad_kernel_fault(struct pt_regs *regs, unsigned long error_code, // Read/write fault in a valid region (the exception table search passed // above), but blocked by KUAP is bad, it can never succeed. if (bad_kuap_fault(regs, address, is_write)) - return true; + return WARN(true, "Bug: %s fault blocked by KUAP!", is_write ? "Write" : "Read"); // What's left? Kernel fault on user in well defined regions (extable // matched), and allowed by KUAP in the faulting context. |