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| author |   Heiko Carstens <heiko.carstens@de.ibm.com> | 2013-08-01 10:16:27 +0200 |
|---|---|---|
| committer |   Martin Schwidefsky <schwidefsky@de.ibm.com> | 2013-08-22 12:20:12 +0200 |
| commit | 6b169ac9b4342ff3a1499bdeb7596aa4f1bc401b (patch) | |
| tree | 3697bebddba3158aefd5481e7009ecd5ae5a1291 /arch/s390/kernel/kprobes.c | |
| parent | s390/switch_to: fix save_access_regs() / restore_access_regs() (diff) | |
| download | linux-dev-6b169ac9b4342ff3a1499bdeb7596aa4f1bc401b.tar.xz linux-dev-6b169ac9b4342ff3a1499bdeb7596aa4f1bc401b.zip | |
s390/kprobes: add support for compare and branch instructions
The compare and branch instructions (not relative) all need special
handling when kprobed:
- if a branch was taken, the instruction pointer should be left alone
- if a branch was not taken, the instruction pointer must be adjusted
The compare and branch instructions family was introduced with the general
instruction extension facility (z10).
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel/kprobes.c')
| -rw-r--r-- | arch/s390/kernel/kprobes.c | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c index 3388b2b2a07d..adbbe7f1cb0d 100644 --- a/arch/s390/kernel/kprobes.c +++ b/arch/s390/kernel/kprobes.c @@ -105,14 +105,31 @@ static int __kprobes get_fixup_type(kprobe_opcode_t *insn) fixup |= FIXUP_RETURN_REGISTER; break; case 0xeb: - if ((insn[2] & 0xff) == 0x44 || /* bxhg */ - (insn[2] & 0xff) == 0x45) /* bxleg */ + switch (insn[2] & 0xff) { + case 0x44: /* bxhg */ + case 0x45: /* bxleg */ fixup = FIXUP_BRANCH_NOT_TAKEN; + break; + } break; case 0xe3: /* bctg */ if ((insn[2] & 0xff) == 0x46) fixup = FIXUP_BRANCH_NOT_TAKEN; break; + case 0xec: + switch (insn[2] & 0xff) { + case 0xe5: /* clgrb */ + case 0xe6: /* cgrb */ + case 0xf6: /* crb */ + case 0xf7: /* clrb */ + case 0xfc: /* cgib */ + case 0xfd: /* cglib */ + case 0xfe: /* cib */ + case 0xff: /* clib */ + fixup = FIXUP_BRANCH_NOT_TAKEN; + break; + } + break; } return fixup; } |