diff options
| author | Keshavamurthy Anil S <anil.s.keshavamurthy@intel.com> | 2005-09-06 15:19:35 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-09-07 16:58:01 -0700 |
| commit | deac66ae454cacf942c051b86d9232af546fb187 (patch) | |
| tree | 17a72e7a2dcf2d1a93a6afdef661f290b1888f1c /arch/ia64 | |
| parent | bce0649417d6e71f6df8ab7b11103d247913b142 (diff) | |
[PATCH] kprobes: fix bug when probed on task and isr functions
This patch fixes a race condition where in system used to hang or sometime
crash within minutes when kprobes are inserted on ISR routine and a task
routine.
The fix has been stress tested on i386, ia64, pp64 and on x86_64. To
reproduce the problem insert kprobes on schedule() and do_IRQ() functions
and you should see hang or system crash.
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Acked-by: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/ia64')
| -rw-r--r-- | arch/ia64/kernel/kprobes.c | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c index 4b1bd539ec4..471086b808a 100644 --- a/arch/ia64/kernel/kprobes.c +++ b/arch/ia64/kernel/kprobes.c @@ -95,6 +95,17 @@ static void __kprobes update_kprobe_inst_flag(uint template, uint slot, p->ainsn.inst_flag = 0; p->ainsn.target_br_reg = 0; + /* Check for Break instruction + * Bits 37:40 Major opcode to be zero + * Bits 27:32 X6 to be zero + * Bits 32:35 X3 to be zero + */ + if ((!major_opcode) && (!((kprobe_inst >> 27) & 0x1FF)) ) { + /* is a break instruction */ + p->ainsn.inst_flag |= INST_FLAG_BREAK_INST; + return; + } + if (bundle_encoding[template][slot] == B) { switch (major_opcode) { case INDIRECT_CALL_OPCODE: @@ -542,8 +553,11 @@ static void __kprobes prepare_ss(struct kprobe *p, struct pt_regs *regs) unsigned long bundle_addr = (unsigned long) &p->opcode.bundle; unsigned long slot = (unsigned long)p->addr & 0xf; - /* Update instruction pointer (IIP) and slot number (IPSR.ri) */ - regs->cr_iip = bundle_addr & ~0xFULL; + /* single step inline if break instruction */ + if (p->ainsn.inst_flag == INST_FLAG_BREAK_INST) + regs->cr_iip = (unsigned long)p->addr & ~0xFULL; + else + regs->cr_iip = bundle_addr & ~0xFULL; if (slot > 2) slot = 0; @@ -599,7 +613,9 @@ static int __kprobes pre_kprobes_handler(struct die_args *args) if (kprobe_running()) { p = get_kprobe(addr); if (p) { - if (kprobe_status == KPROBE_HIT_SS) { + if ( (kprobe_status == KPROBE_HIT_SS) && + (p->ainsn.inst_flag == INST_FLAG_BREAK_INST)) { + ia64_psr(regs)->ss = 0; unlock_kprobes(); goto no_kprobe; } |