From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:59026 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751798AbdLUJg6 (ORCPT ); Thu, 21 Dec 2017 04:36:58 -0500 Subject: Patch "arm: kprobes: Fix the return address of multiple kretprobes" has been added to the 4.4-stable tree To: mhiramat@kernel.org, alexander.levin@verizon.com, gregkh@linuxfoundation.org, kumano.prog@gmail.com, tixy@linaro.org Cc: , From: Date: Thu, 21 Dec 2017 10:36:44 +0100 Message-ID: <1513849004173122@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled arm: kprobes: Fix the return address of multiple kretprobes to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: arm-kprobes-fix-the-return-address-of-multiple-kretprobes.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From foo@baz Thu Dec 21 10:35:49 CET 2017 From: Masami Hiramatsu Date: Tue, 14 Feb 2017 00:05:59 +0900 Subject: arm: kprobes: Fix the return address of multiple kretprobes From: Masami Hiramatsu [ Upstream commit 06553175f585b52509c7df37d6f4a50aacb7b211 ] This is arm port of commit 737480a0d525 ("kprobes/x86: Fix the return address of multiple kretprobes"). Fix the return address of subsequent kretprobes when multiple kretprobes are set on the same function. For example: # cd /sys/kernel/debug/tracing # echo "r:event1 sys_symlink" > kprobe_events # echo "r:event2 sys_symlink" >> kprobe_events # echo 1 > events/kprobes/enable # ln -s /tmp/foo /tmp/bar (without this patch) # cat trace | grep -v ^# ln-82 [000] dn.2 68.446525: event1: (kretprobe_trampoline+0x0/0x18 <- SyS_symlink) ln-82 [000] dn.2 68.447831: event2: (ret_fast_syscall+0x0/0x1c <- SyS_symlink) (with this patch) # cat trace | grep -v ^# ln-81 [000] dn.1 39.463469: event1: (ret_fast_syscall+0x0/0x1c <- SyS_symlink) ln-81 [000] dn.1 39.464701: event2: (ret_fast_syscall+0x0/0x1c <- SyS_symlink) Signed-off-by: Masami Hiramatsu Cc: KUMANO Syuhei Signed-off-by: Jon Medhurst Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- arch/arm/probes/kprobes/core.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) --- a/arch/arm/probes/kprobes/core.c +++ b/arch/arm/probes/kprobes/core.c @@ -433,6 +433,7 @@ static __used __kprobes void *trampoline 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); @@ -455,14 +456,34 @@ static __used __kprobes void *trampoline /* 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); } - orig_ret_address = (unsigned long)ri->ret_addr; recycle_rp_inst(ri, &empty_rp); if (orig_ret_address != trampoline_address) @@ -474,7 +495,6 @@ static __used __kprobes void *trampoline break; } - kretprobe_assert(ri, orig_ret_address, trampoline_address); kretprobe_hash_unlock(current, &flags); hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) { Patches currently in stable-queue which might be from mhiramat@kernel.org are queue-4.4/arm-kprobes-fix-the-return-address-of-multiple-kretprobes.patch