From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, kernel test robot <lkp@intel.com>,
Masami Hiramatsu <mhiramat@kernel.org>
Subject: [PATCH 4.19 09/12] Revert "ia64: kprobes: Use generic kretprobe trampoline handler"
Date: Fri, 29 Apr 2022 12:41:26 +0200 [thread overview]
Message-ID: <20220429104048.733242837@linuxfoundation.org> (raw)
In-Reply-To: <20220429104048.459089941@linuxfoundation.org>
From: Masami Hiramatsu <mhiramat@kernel.org>
This reverts commit d3380de483d55d904fb94a241406b34ed2fada7d.
Since this commit is a part of generic kretprobe trampoline
handler series, without the other patches in that series, this
causes a build error on ia64.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/ia64/kernel/kprobes.c | 77 +++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 75 insertions(+), 2 deletions(-)
--- a/arch/ia64/kernel/kprobes.c
+++ b/arch/ia64/kernel/kprobes.c
@@ -409,9 +409,83 @@ static void kretprobe_trampoline(void)
{
}
+/*
+ * At this point the target function has been tricked into
+ * returning into our trampoline. Lookup the associated instance
+ * and then:
+ * - call the handler function
+ * - cleanup by marking the instance as unused
+ * - long jump back to the original return address
+ */
int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
{
- regs->cr_iip = __kretprobe_trampoline_handler(regs, kretprobe_trampoline, NULL);
+ 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 =
+ ((struct fnptr *)kretprobe_trampoline)->ip;
+
+ 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
+ */
+ 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;
+ }
+
+ regs->cr_iip = orig_ret_address;
+
+ hlist_for_each_entry_safe(ri, tmp, head, hlist) {
+ if (ri->task != current)
+ /* another task is sharing our hash bucket */
+ continue;
+
+ if (ri->rp && ri->rp->handler)
+ ri->rp->handler(ri, regs);
+
+ orig_ret_address = (unsigned long)ri->ret_addr;
+ 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_assert(ri, orig_ret_address, trampoline_address);
+
+ kretprobe_hash_unlock(current, &flags);
+
+ hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) {
+ hlist_del(&ri->hlist);
+ kfree(ri);
+ }
/*
* By returning a non-zero value, we are telling
* kprobe_handler() that we don't want the post_handler
@@ -424,7 +498,6 @@ void __kprobes arch_prepare_kretprobe(st
struct pt_regs *regs)
{
ri->ret_addr = (kprobe_opcode_t *)regs->b0;
- ri->fp = NULL;
/* Replace the return addr with trampoline addr */
regs->b0 = ((struct fnptr *)kretprobe_trampoline)->ip;
next prev parent reply other threads:[~2022-04-29 10:43 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-29 10:41 [PATCH 4.19 00/12] 4.19.241-rc1 review Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 4.19 01/12] media: vicodec: upon release, call m2m release before freeing ctrl handler Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 4.19 02/12] floppy: disable FDRAWCMD by default Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 4.19 03/12] hamradio: defer 6pack kfree after unregister_netdev Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 4.19 04/12] hamradio: remove needs_free_netdev to avoid UAF Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 4.19 05/12] net/sched: cls_u32: fix netns refcount changes in u32_change() Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 4.19 06/12] powerpc/64/interrupt: Temporarily save PPR on stack to fix register corruption due to SLB miss Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 4.19 07/12] powerpc/64s: Unmerge EX_LR and EX_DAR Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 4.19 08/12] Revert "ia64: kprobes: Fix to pass correct trampoline address to the handler" Greg Kroah-Hartman
2022-04-29 10:41 ` Greg Kroah-Hartman [this message]
2022-04-29 10:41 ` [PATCH 4.19 10/12] ia64: kprobes: Fix to pass correct trampoline address to the handler Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 4.19 11/12] Revert "net: ethernet: stmmac: fix altr_tse_pcs function when using a fixed-link" Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 4.19 12/12] lightnvm: disable the subsystem Greg Kroah-Hartman
2022-04-29 18:36 ` [PATCH 4.19 00/12] 4.19.241-rc1 review Shuah Khan
2022-04-29 23:48 ` Guenter Roeck
2022-04-30 5:55 ` Naresh Kamboju
2022-04-30 10:18 ` Sudip Mukherjee
2022-05-03 10:41 ` Pavel Machek
2022-05-03 14:16 ` Guenter Roeck
2022-05-03 14:25 ` Greg Kroah-Hartman
2022-05-03 16:41 ` Guenter Roeck
2022-05-09 8:04 ` Greg Kroah-Hartman
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20220429104048.733242837@linuxfoundation.org \
--to=gregkh@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=lkp@intel.com \
--cc=mhiramat@kernel.org \
--cc=stable@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).