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| author | Keshavamurthy Anil S <anil.s.keshavamurthy@intel.com> | 2005-11-22 14:15:49 -0800 |
|---|---|---|
| committer | Tony Luck <tony.luck@intel.com> | 2005-11-29 09:24:39 -0800 |
| commit | 5a94bcfd2a18edcf368b3128c7df07b58e529932 (patch) | |
| tree | 12e6240717e2dbdce0e157a097629b76d07afdae /arch/ia64 | |
| parent | b77dae5293efba42ea1ff04d410ee68e66d5b0cf (diff) | |
| download | lwn-5a94bcfd2a18edcf368b3128c7df07b58e529932.tar.gz lwn-5a94bcfd2a18edcf368b3128c7df07b58e529932.zip | |
[IA64] Remove getting break_num by decoding instruction
break.b always sets cr.iim to 0 and the current code tries to
get the break_num by decoding instruction. However, their
seems to be a race condition while reading the regs->cr_iip,
as on other cpu the break.b at regs->cr_iip might have been
replaced with the original instruction as a result of
unregister_kprobe() and hence decoding instruction to
obtain break_num will result in wrong value in this case.
Also includes changes to kprobes.c which now has to handle
break number zero.
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'arch/ia64')
| -rw-r--r-- | arch/ia64/kernel/kprobes.c | 2 | ||||
| -rw-r--r-- | arch/ia64/kernel/traps.c | 18 |
2 files changed, 1 insertions, 19 deletions
diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c index 801eeaeaf3de..2895d6e6062f 100644 --- a/arch/ia64/kernel/kprobes.c +++ b/arch/ia64/kernel/kprobes.c @@ -740,7 +740,7 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, switch(val) { case DIE_BREAK: /* err is break number from ia64_bad_break() */ - if (args->err == 0x80200 || args->err == 0x80300) + if (args->err == 0x80200 || args->err == 0x80300 || args->err == 0) if (pre_kprobes_handler(args)) ret = NOTIFY_STOP; break; diff --git a/arch/ia64/kernel/traps.c b/arch/ia64/kernel/traps.c index fba5fdd1f968..d3e0ecb56d62 100644 --- a/arch/ia64/kernel/traps.c +++ b/arch/ia64/kernel/traps.c @@ -132,24 +132,6 @@ __kprobes ia64_bad_break (unsigned long break_num, struct pt_regs *regs) siginfo_t siginfo; int sig, code; - /* break.b always sets cr.iim to 0, which causes problems for - * debuggers. Get the real break number from the original instruction, - * but only for kernel code. User space break.b is left alone, to - * preserve the existing behaviour. All break codings have the same - * format, so there is no need to check the slot type. - */ - if (break_num == 0 && !user_mode(regs)) { - struct ia64_psr *ipsr = ia64_psr(regs); - unsigned long *bundle = (unsigned long *)regs->cr_iip; - unsigned long slot; - switch (ipsr->ri) { - case 0: slot = (bundle[0] >> 5); break; - case 1: slot = (bundle[0] >> 46) | (bundle[1] << 18); break; - default: slot = (bundle[1] >> 23); break; - } - break_num = ((slot >> 36 & 1) << 20) | (slot >> 6 & 0xfffff); - } - /* SIGILL, SIGFPE, SIGSEGV, and SIGBUS want these field initialized: */ siginfo.si_addr = (void __user *) (regs->cr_iip + ia64_psr(regs)->ri); siginfo.si_imm = break_num; |