From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keshavamurthy Anil S Date: Thu, 26 May 2005 21:25:39 +0000 Subject: Kprobes IA64 check jprobe break before handling Message-Id: <20050526142539.A24770@unix-os.sc.intel.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: akpm@osdl.org Cc: Linux Kernel , linux-ia64@vger.kernel.org, anil.s.keshavamurthy@intel.com, Rusty Lynch , systemtap@sources.redhat.com From: anil.s.keshavamurthy@intel.com Subject: Kprobes IA64 check jprobe break before handling Once the jprobe instrumented function returns, it executes a jprobe_break which is a break instruction with __IA64_JPROBE_BREAK value. The current patch checks for this break value, before assuming that jprobe instrumented function just completed. The previous code was not checking for this value and that was a bug. Signed-off-by: Anil S Keshavamurthy ================================= arch/ia64/kernel/kprobes.c | 10 +++++++--- 1 files changed, 7 insertions(+), 3 deletions(-) Index: linux-2.6.12-rc5/arch/ia64/kernel/kprobes.c =================================--- linux-2.6.12-rc5.orig/arch/ia64/kernel/kprobes.c +++ linux-2.6.12-rc5/arch/ia64/kernel/kprobes.c @@ -284,10 +284,11 @@ static void prepare_ss(struct kprobe *p, ia64_psr(regs)->ss = 1; } -static int pre_kprobes_handler(struct pt_regs *regs) +static int pre_kprobes_handler(struct die_args *args) { struct kprobe *p; int ret = 0; + struct pt_regs *regs = args->regs; kprobe_opcode_t *addr = (kprobe_opcode_t *)instruction_pointer(regs); preempt_disable(); @@ -302,7 +303,7 @@ static int pre_kprobes_handler(struct pt } arch_disarm_kprobe(p); ret = 1; - } else { + } else if (args->err = __IA64_BREAK_JPROBE) { /* * jprobe instrumented function just completed */ @@ -310,6 +311,9 @@ static int pre_kprobes_handler(struct pt if (p->break_handler && p->break_handler(p, regs)) { goto ss_probe; } + } else { + /* Not our break */ + goto no_kprobe; } } @@ -380,7 +384,7 @@ int kprobe_exceptions_notify(struct noti struct die_args *args = (struct die_args *)data; switch(val) { case DIE_BREAK: - if (pre_kprobes_handler(args->regs)) + if (pre_kprobes_handler(args)) return NOTIFY_STOP; break; case DIE_SS: