diff options
author | Gui,Jian <guij@cn.ibm.com> | 2006-10-31 21:50:15 -0500 |
---|---|---|
committer | Paul Mackerras <paulus@samba.org> | 2006-10-31 23:14:12 -0500 |
commit | 0d69a052d4d7c4085706b9ac0d1bd28ff90c9fca (patch) | |
tree | 8dada42c1c58e9450161e88e67d304c68917f3a8 /arch | |
parent | 292f86f005e3867277b2126c2399eea3e773a4fc (diff) |
[POWERPC] Disallow kprobes on emulate_step and branch_taken
On powerpc, probing on emulate_step function will crash 2.6.18.1 when
it is triggered.
When kprobe is triggered, emulate_step() is on its kernel path and
will cause recursive kprobe fault. And branch_taken() is called
in emulate_step(). This disallows kprobes on both of them.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/powerpc/lib/sstep.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c index 9590ba780b98..7e8ded051b5b 100644 --- a/arch/powerpc/lib/sstep.c +++ b/arch/powerpc/lib/sstep.c | |||
@@ -9,6 +9,7 @@ | |||
9 | * 2 of the License, or (at your option) any later version. | 9 | * 2 of the License, or (at your option) any later version. |
10 | */ | 10 | */ |
11 | #include <linux/kernel.h> | 11 | #include <linux/kernel.h> |
12 | #include <linux/kprobes.h> | ||
12 | #include <linux/ptrace.h> | 13 | #include <linux/ptrace.h> |
13 | #include <asm/sstep.h> | 14 | #include <asm/sstep.h> |
14 | #include <asm/processor.h> | 15 | #include <asm/processor.h> |
@@ -25,7 +26,7 @@ extern char system_call_common[]; | |||
25 | /* | 26 | /* |
26 | * Determine whether a conditional branch instruction would branch. | 27 | * Determine whether a conditional branch instruction would branch. |
27 | */ | 28 | */ |
28 | static int branch_taken(unsigned int instr, struct pt_regs *regs) | 29 | static int __kprobes branch_taken(unsigned int instr, struct pt_regs *regs) |
29 | { | 30 | { |
30 | unsigned int bo = (instr >> 21) & 0x1f; | 31 | unsigned int bo = (instr >> 21) & 0x1f; |
31 | unsigned int bi; | 32 | unsigned int bi; |
@@ -51,7 +52,7 @@ static int branch_taken(unsigned int instr, struct pt_regs *regs) | |||
51 | * or -1 if the instruction is one that should not be stepped, | 52 | * or -1 if the instruction is one that should not be stepped, |
52 | * such as an rfid, or a mtmsrd that would clear MSR_RI. | 53 | * such as an rfid, or a mtmsrd that would clear MSR_RI. |
53 | */ | 54 | */ |
54 | int emulate_step(struct pt_regs *regs, unsigned int instr) | 55 | int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr) |
55 | { | 56 | { |
56 | unsigned int opcode, rd; | 57 | unsigned int opcode, rd; |
57 | unsigned long int imm; | 58 | unsigned long int imm; |