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author | Peter Zijlstra <peterz@infradead.org> | 2022-03-08 18:30:20 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-03-01 15:16:48 +0300 |
commit | b253061d4b863f0e9ebf25a3cf0313501a5d51b4 (patch) | |
tree | 1ce2e4b358269c5e4c35d84ccef392a9677dd73a /arch | |
parent | e752912ce18c5ec0f40c86541ef38805d6f47581 (diff) | |
download | linux-b253061d4b863f0e9ebf25a3cf0313501a5d51b4.tar.xz |
x86/ibt,paravirt: Use text_gen_insn() for paravirt_patch()
Upstream commit: ba27d1a80871eb8dbeddf34ec7d396c149cbb8d7
Less duplication is more better.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154317.697253958@infradead.org
[ Keep struct branch. ]
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/x86/include/asm/text-patching.h | 20 | ||||
-rw-r--r-- | arch/x86/kernel/paravirt.c | 22 |
2 files changed, 19 insertions, 23 deletions
diff --git a/arch/x86/include/asm/text-patching.h b/arch/x86/include/asm/text-patching.h index 1c4cfb1c6e4f..c6015b407461 100644 --- a/arch/x86/include/asm/text-patching.h +++ b/arch/x86/include/asm/text-patching.h @@ -96,32 +96,40 @@ union text_poke_insn { }; static __always_inline -void *text_gen_insn(u8 opcode, const void *addr, const void *dest) +void __text_gen_insn(void *buf, u8 opcode, const void *addr, const void *dest, int size) { - static union text_poke_insn insn; /* per instance */ - int size = text_opcode_size(opcode); + union text_poke_insn *insn = buf; + + BUG_ON(size < text_opcode_size(opcode)); /* * Hide the addresses to avoid the compiler folding in constants when * referencing code, these can mess up annotations like * ANNOTATE_NOENDBR. */ + OPTIMIZER_HIDE_VAR(insn); OPTIMIZER_HIDE_VAR(addr); OPTIMIZER_HIDE_VAR(dest); - insn.opcode = opcode; + insn->opcode = opcode; if (size > 1) { - insn.disp = (long)dest - (long)(addr + size); + insn->disp = (long)dest - (long)(addr + size); if (size == 2) { /* * Ensure that for JMP8 the displacement * actually fits the signed byte. */ - BUG_ON((insn.disp >> 31) != (insn.disp >> 7)); + BUG_ON((insn->disp >> 31) != (insn->disp >> 7)); } } +} +static __always_inline +void *text_gen_insn(u8 opcode, const void *addr, const void *dest) +{ + static union text_poke_insn insn; /* per instance */ + __text_gen_insn(&insn, opcode, addr, dest, text_opcode_size(opcode)); return &insn.text; } diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c index e21937680d1f..5bea8d93883a 100644 --- a/arch/x86/kernel/paravirt.c +++ b/arch/x86/kernel/paravirt.c @@ -55,28 +55,16 @@ void __init default_banner(void) static const unsigned char ud2a[] = { 0x0f, 0x0b }; struct branch { - unsigned char opcode; - u32 delta; + unsigned char opcode; + u32 delta; } __attribute__((packed)); static unsigned paravirt_patch_call(void *insn_buff, const void *target, unsigned long addr, unsigned len) { - const int call_len = 5; - struct branch *b = insn_buff; - unsigned long delta = (unsigned long)target - (addr+call_len); - - if (len < call_len) { - pr_warn("paravirt: Failed to patch indirect CALL at %ps\n", (void *)addr); - /* Kernel might not be viable if patching fails, bail out: */ - BUG_ON(1); - } - - b->opcode = 0xe8; /* call */ - b->delta = delta; - BUILD_BUG_ON(sizeof(*b) != call_len); - - return call_len; + __text_gen_insn(insn_buff, CALL_INSN_OPCODE, + (void *)addr, target, CALL_INSN_SIZE); + return CALL_INSN_SIZE; } #ifdef CONFIG_PARAVIRT_XXL |