mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-05-08 00:29:36 -04:00
Code Issues Packages Projects Releases Wiki Activity

s390: kprobes: Use generic kretprobe trampoline handler

Browse Source 
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>
Link: https://lore.kernel.org/r/159870612453.1229682.15950927742606892302.stgit@devnote2
This commit is contained in:
Masami Hiramatsu
2020-08-29 22:02:04 +09:00
committed by Ingo Molnar
parent b6c5a58dd8
commit 26a24a6b43
1 changed files with 2 additions and 77 deletions
Download Patch File Download Diff File Expand all files Collapse all files

79
arch/s390/kernel/kprobes.c
View File

@@ -228,6 +228,7 @@ NOKPROBE_SYMBOL(pop_kprobe);
void arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs)
{
ri->ret_addr = (kprobe_opcode_t *) regs->gprs[14];
ri->fp = NULL;
/* Replace the return addr with trampoline addr */
regs->gprs[14] = (unsigned long) &kretprobe_trampoline;
@@ -331,83 +332,7 @@ static void __used kretprobe_trampoline_holder(void)
*/
static int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
{
struct kretprobe_instance *ri;
struct hlist_head *head, empty_rp;
struct hlist_node *tmp;
unsigned long flags, orig_ret_address;
unsigned long trampoline_address;
kprobe_opcode_t *correct_ret_addr;
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 an multiple functions in the call path
* have a return probe installed on them, and/or more than one return
* return probe was registered for a target function.
*
* We can handle this because:
* - instances are always inserted at the head of the list
* - when multiple return probes are registered for the same
* function, the first instance's ret_addr will point to the
* real return address, and all the rest will point to
* kretprobe_trampoline
*/
ri = NULL;
orig_ret_address = 0;
correct_ret_addr = NULL;
trampoline_address = (unsigned long) &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) {
ri->ret_addr = correct_ret_addr;
ri->rp->handler(ri, regs);
}
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;
}
regs->psw.addr = orig_ret_address;
kretprobe_hash_unlock(current, &flags);
hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) {
hlist_del(&ri->hlist);
kfree(ri);
}
regs->psw.addr = __kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL);
/*
* By returning a non-zero value, we are telling
* kprobe_handler() that we don't want the post_handler