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authorMasami Hiramatsu <mhiramat@kernel.org>2020-08-29 22:00:58 +0900
committerIngo Molnar <mingo@kernel.org>2020-09-08 11:52:33 +0200
commit03c8a4a447008c1a755cd32bc89af24119bd08f1 (patch)
tree3238bcdd0c7a44d486a3fbf2b84211d388fde709 /arch/csky
parentf75dd136b65cccfaf3869be5380f401538fa9f72 (diff)
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csky: kprobes: Use generic kretprobe trampoline handler
Use the generic kretprobe trampoline handler. Don't use framepointer verification. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/159870605775.1229682.2627276871589951304.stgit@devnote2
Diffstat (limited to 'arch/csky')
-rw-r--r--arch/csky/kernel/probes/kprobes.c77
1 files changed, 2 insertions, 75 deletions
diff --git a/arch/csky/kernel/probes/kprobes.c b/arch/csky/kernel/probes/kprobes.c
index f0f733b7ac5a..589f090f48b9 100644
--- a/arch/csky/kernel/probes/kprobes.c
+++ b/arch/csky/kernel/probes/kprobes.c
@@ -404,87 +404,14 @@ int __init arch_populate_kprobe_blacklist(void)
void __kprobes __used *trampoline_probe_handler(struct pt_regs *regs)
{
- struct kretprobe_instance *ri = NULL;
- struct hlist_head *head, empty_rp;
- struct hlist_node *tmp;
- unsigned long flags, orig_ret_address = 0;
- unsigned long trampoline_address =
- (unsigned long)&kretprobe_trampoline;
- kprobe_opcode_t *correct_ret_addr = NULL;
-
- INIT_HLIST_HEAD(&empty_rp);
- kretprobe_hash_lock(current, &head, &flags);
-
- /*
- * It is possible to have multiple instances associated with a given
- * task either because multiple functions in the call path have
- * return probes installed on them, and/or more than one
- * return probe was registered for a target function.
- *
- * We can handle this because:
- * - instances are always pushed into the head of the list
- * - when multiple return probes are registered for the same
- * function, the (chronologically) first instance's ret_addr
- * will be the real return address, and all the rest will
- * point to kretprobe_trampoline.
- */
- hlist_for_each_entry_safe(ri, tmp, head, hlist) {
- if (ri->task != current)
- /* another task is sharing our hash bucket */
- continue;
-
- orig_ret_address = (unsigned long)ri->ret_addr;
-
- if (orig_ret_address != trampoline_address)
- /*
- * This is the real return address. Any other
- * instances associated with this task are for
- * other calls deeper on the call stack
- */
- break;
- }
-
- kretprobe_assert(ri, orig_ret_address, trampoline_address);
-
- correct_ret_addr = ri->ret_addr;
- hlist_for_each_entry_safe(ri, tmp, head, hlist) {
- if (ri->task != current)
- /* another task is sharing our hash bucket */
- continue;
-
- orig_ret_address = (unsigned long)ri->ret_addr;
- if (ri->rp && ri->rp->handler) {
- __this_cpu_write(current_kprobe, &ri->rp->kp);
- get_kprobe_ctlblk()->kprobe_status = KPROBE_HIT_ACTIVE;
- ri->ret_addr = correct_ret_addr;
- ri->rp->handler(ri, regs);
- __this_cpu_write(current_kprobe, NULL);
- }
-
- recycle_rp_inst(ri, &empty_rp);
-
- if (orig_ret_address != trampoline_address)
- /*
- * This is the real return address. Any other
- * instances associated with this task are for
- * other calls deeper on the call stack
- */
- break;
- }
-
- kretprobe_hash_unlock(current, &flags);
-
- hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) {
- hlist_del(&ri->hlist);
- kfree(ri);
- }
- return (void *)orig_ret_address;
+ return (void *)kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL);
}
void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
struct pt_regs *regs)
{
ri->ret_addr = (kprobe_opcode_t *)regs->lr;
+ ri->fp = NULL;
regs->lr = (unsigned long) &kretprobe_trampoline;
}