diff options
Diffstat (limited to 'arch/x86/kernel/kprobes/opt.c')
| -rw-r--r-- | arch/x86/kernel/kprobes/opt.c | 35 |
1 files changed, 14 insertions, 21 deletions
diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c index 08eb23074f92..3d6201492006 100644 --- a/arch/x86/kernel/kprobes/opt.c +++ b/arch/x86/kernel/kprobes/opt.c @@ -15,6 +15,7 @@ #include <linux/extable.h> #include <linux/kdebug.h> #include <linux/kallsyms.h> +#include <linux/kgdb.h> #include <linux/ftrace.h> #include <linux/objtool.h> #include <linux/pgtable.h> @@ -272,19 +273,6 @@ static int insn_is_indirect_jump(struct insn *insn) return ret; } -static bool is_padding_int3(unsigned long addr, unsigned long eaddr) -{ - unsigned char ops; - - for (; addr < eaddr; addr++) { - if (get_kernel_nofault(ops, (void *)addr) < 0 || - ops != INT3_INSN_OPCODE) - return false; - } - - return true; -} - /* Decode whole function to ensure any instructions don't jump into target */ static int can_optimize(unsigned long paddr) { @@ -312,6 +300,8 @@ 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, @@ -321,16 +311,19 @@ 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; +#ifdef CONFIG_KGDB /* - * In the case of detecting unknown breakpoint, this could be - * a padding INT3 between functions. Let's check that all the - * rest of the bytes are also INT3. + * If there is a dynamically installed kgdb sw breakpoint, + * this function should not be probed. */ - if (insn.opcode.bytes[0] == INT3_INSN_OPCODE) - return is_padding_int3(addr, paddr - offset + size) ? 1 : 0; - + if (insn.opcode.bytes[0] == INT3_INSN_OPCODE && + kgdb_has_hit_break(addr)) + return 0; +#endif /* Recover address */ insn.kaddr = (void *)addr; insn.next_byte = (void *)(addr + insn.length); |