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| author | Borislav Petkov <bp@suse.de> | 2020-11-16 18:10:11 +0100 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2021-03-15 11:28:20 +0100 |
| commit | 77e768ec1391dc0d6cd89822aa60b9a1c1bd8128 (patch) | |
| tree | 0413f54c729261a222cc858392b3f5e5af67f0eb | |
| parent | 1580f488ea8c6a62d002be364248c34c2f2e430b (diff) | |
| download | linux-77e768ec1391dc0d6cd89822aa60b9a1c1bd8128.tar.gz | |
x86/kprobes: Convert to insn_decode()
Simplify code, improve decoding error checking. Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Link: https://lkml.kernel.org/r/20210304174237.31945-12-bp@alien8.de
| -rw-r--r-- | arch/x86/kernel/kprobes/core.c | 17 | ||||
| -rw-r--r-- | arch/x86/kernel/kprobes/opt.c | 9 |
2 files changed, 18 insertions, 8 deletions
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index df776cdca327..60a540fcbd56 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -265,6 +265,8 @@ static int can_probe(unsigned long paddr) /* Decode instructions */ addr = paddr - offset; while (addr < paddr) { + int ret; + /* * Check if the instruction has been modified by another * kprobe, in which case we replace the breakpoint by the @@ -276,8 +278,10 @@ static int can_probe(unsigned long paddr) __addr = recover_probed_instruction(buf, addr); if (!__addr) return 0; - kernel_insn_init(&insn, (void *)__addr, MAX_INSN_SIZE); - insn_get_length(&insn); + + ret = insn_decode(&insn, (void *)__addr, MAX_INSN_SIZE, INSN_MODE_KERN); + if (ret < 0) + return 0; /* * Another debugging subsystem might insert this breakpoint. @@ -301,8 +305,8 @@ static int can_probe(unsigned long paddr) int __copy_instruction(u8 *dest, u8 *src, u8 *real, struct insn *insn) { kprobe_opcode_t buf[MAX_INSN_SIZE]; - unsigned long recovered_insn = - recover_probed_instruction(buf, (unsigned long)src); + unsigned long recovered_insn = recover_probed_instruction(buf, (unsigned long)src); + int ret; if (!recovered_insn || !insn) return 0; @@ -312,8 +316,9 @@ int __copy_instruction(u8 *dest, u8 *src, u8 *real, struct insn *insn) MAX_INSN_SIZE)) return 0; - kernel_insn_init(insn, dest, MAX_INSN_SIZE); - insn_get_length(insn); + ret = insn_decode(insn, dest, MAX_INSN_SIZE, INSN_MODE_KERN); + if (ret < 0) + return 0; /* We can not probe force emulate prefixed instruction */ if (insn_has_emulate_prefix(insn)) diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c index 08eb23074f92..4299fc865732 100644 --- a/arch/x86/kernel/kprobes/opt.c +++ b/arch/x86/kernel/kprobes/opt.c @@ -312,6 +312,8 @@ static int can_optimize(unsigned long paddr) addr = paddr - offset; while (addr < paddr - offset + size) { /* Decode until function end */ unsigned long recovered_insn; + int ret; + if (search_exception_tables(addr)) /* * Since some fixup code will jumps into this function, @@ -321,8 +323,11 @@ static int can_optimize(unsigned long paddr) recovered_insn = recover_probed_instruction(buf, addr); if (!recovered_insn) return 0; - kernel_insn_init(&insn, (void *)recovered_insn, MAX_INSN_SIZE); - insn_get_length(&insn); + + ret = insn_decode(&insn, (void *)recovered_insn, MAX_INSN_SIZE, INSN_MODE_KERN); + if (ret < 0) + return 0; + /* * In the case of detecting unknown breakpoint, this could be * a padding INT3 between functions. Let's check that all the |