diff options
| author | Abhishek Sagar <sagar.abhishek@gmail.com> | 2008-02-06 01:38:22 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2008-02-06 10:41:11 -0800 |
| commit | f47cd9b553aaada602449204513b5a5b29cba263 (patch) | |
| tree | 079ddd399b1aa00a8c413ef51f3b8681a19a6e7e /kernel | |
| parent | 5beec4aa2ac261b0b4992fb41df40a7ab91e4fad (diff) | |
kprobes: kretprobe user entry-handler
Provide support to add an optional user defined callback to be run at
function entry of a kretprobe'd function. Also modify the kprobe smoke
tests to include an entry-handler during the kretprobe sanity test.
Signed-off-by: Abhishek Sagar <sagar.abhishek@gmail.com>
Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Acked-by: Jim Keniston <jkenisto@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/kprobes.c | 9 | ||||
| -rw-r--r-- | kernel/test_kprobes.c | 16 |
2 files changed, 22 insertions, 3 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c index d0493eafea3..7a86e643233 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -699,6 +699,12 @@ static int __kprobes pre_handler_kretprobe(struct kprobe *p, struct kretprobe_instance, uflist); ri->rp = rp; ri->task = current; + + if (rp->entry_handler && rp->entry_handler(ri, regs)) { + spin_unlock_irqrestore(&kretprobe_lock, flags); + return 0; + } + arch_prepare_kretprobe(ri, regs); /* XXX(hch): why is there no hlist_move_head? */ @@ -745,7 +751,8 @@ int __kprobes register_kretprobe(struct kretprobe *rp) INIT_HLIST_HEAD(&rp->used_instances); INIT_HLIST_HEAD(&rp->free_instances); for (i = 0; i < rp->maxactive; i++) { - inst = kmalloc(sizeof(struct kretprobe_instance), GFP_KERNEL); + inst = kmalloc(sizeof(struct kretprobe_instance) + + rp->data_size, GFP_KERNEL); if (inst == NULL) { free_rp_inst(rp); return -ENOMEM; diff --git a/kernel/test_kprobes.c b/kernel/test_kprobes.c index 88cdb109e13..06b6395b45b 100644 --- a/kernel/test_kprobes.c +++ b/kernel/test_kprobes.c @@ -135,6 +135,12 @@ static int test_jprobe(void) #ifdef CONFIG_KRETPROBES static u32 krph_val; +static int entry_handler(struct kretprobe_instance *ri, struct pt_regs *regs) +{ + krph_val = (rand1 / div_factor); + return 0; +} + static int return_handler(struct kretprobe_instance *ri, struct pt_regs *regs) { unsigned long ret = regs_return_value(regs); @@ -144,13 +150,19 @@ static int return_handler(struct kretprobe_instance *ri, struct pt_regs *regs) printk(KERN_ERR "Kprobe smoke test failed: " "incorrect value in kretprobe handler\n"); } + if (krph_val == 0) { + handler_errors++; + printk(KERN_ERR "Kprobe smoke test failed: " + "call to kretprobe entry handler failed\n"); + } - krph_val = (rand1 / div_factor); + krph_val = rand1; return 0; } static struct kretprobe rp = { .handler = return_handler, + .entry_handler = entry_handler, .kp.symbol_name = "kprobe_target" }; @@ -167,7 +179,7 @@ static int test_kretprobe(void) ret = kprobe_target(rand1); unregister_kretprobe(&rp); - if (krph_val == 0) { + if (krph_val != rand1) { printk(KERN_ERR "Kprobe smoke test failed: " "kretprobe handler not called\n"); handler_errors++; |