From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org,
"Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>,
Masami Hiramatsu <mhiramat@kernel.org>,
"Steven Rostedt (VMware)" <rostedt@goodmis.org>,
Michael Ellerman <mpe@ellerman.id.au>
Subject: [PATCH 3.18 07/16] powerpc/kprobes: Pause function_graph tracing during jprobes handling
Date: Tue, 27 Jun 2017 14:49:44 +0200 [thread overview]
Message-ID: <20170627124437.717989859@linuxfoundation.org> (raw)
In-Reply-To: <20170627124436.634493038@linuxfoundation.org>
3.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
commit a9f8553e935f26cb5447f67e280946b0923cd2dc upstream.
This fixes a crash when function_graph and jprobes are used together.
This is essentially commit 237d28db036e ("ftrace/jprobes/x86: Fix
conflict between jprobes and function graph tracing"), but for powerpc.
Jprobes breaks function_graph tracing since the jprobe hook needs to use
jprobe_return(), which never returns back to the hook, but instead to
the original jprobe'd function. The solution is to momentarily pause
function_graph tracing before invoking the jprobe hook and re-enable it
when returning back to the original jprobe'd function.
Fixes: 6794c78243bf ("powerpc64: port of the function graph tracer")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/powerpc/kernel/kprobes.c | 11 +++++++++++
1 file changed, 11 insertions(+)
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -514,6 +514,15 @@ int __kprobes setjmp_pre_handler(struct
#endif
#endif
+ /*
+ * jprobes use jprobe_return() which skips the normal return
+ * path of the function, and this messes up the accounting of the
+ * function graph tracer.
+ *
+ * Pause function graph tracing while performing the jprobe function.
+ */
+ pause_graph_tracing();
+
return 1;
}
@@ -536,6 +545,8 @@ int __kprobes longjmp_break_handler(stru
* saved regs...
*/
memcpy(regs, &kcb->jprobe_saved_regs, sizeof(struct pt_regs));
+ /* It's OK to start function graph tracing again */
+ unpause_graph_tracing();
preempt_enable_no_resched();
return 1;
}
next prev parent reply other threads:[~2017-06-27 13:01 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-27 12:49 [PATCH 3.18 00/16] 3.18.59-stable review Greg Kroah-Hartman
2017-06-27 12:49 ` [PATCH 3.18 01/16] fs/exec.c: account for argv/envp pointers Greg Kroah-Hartman
2017-06-27 12:49 ` [PATCH 3.18 02/16] autofs: sanity check status reported with AUTOFS_DEV_IOCTL_FAIL Greg Kroah-Hartman
2017-06-27 12:49 ` [PATCH 3.18 03/16] lib/cmdline.c: fix get_options() overflow while parsing ranges Greg Kroah-Hartman
2017-06-27 12:49 ` [PATCH 3.18 04/16] KVM: PPC: Book3S HV: Preserve userspace HTM state properly Greg Kroah-Hartman
2017-06-27 12:49 ` [PATCH 3.18 05/16] CIFS: Improve readdir verbosity Greg Kroah-Hartman
2017-06-27 12:49 ` [PATCH 3.18 06/16] signal: Only reschedule timers on signals timers have sent Greg Kroah-Hartman
2017-06-27 12:49 ` Greg Kroah-Hartman [this message]
2017-06-27 12:49 ` [PATCH 3.18 08/16] Input: i8042 - add Fujitsu Lifebook AH544 to notimeout list Greg Kroah-Hartman
2017-06-27 12:49 ` [PATCH 3.18 09/16] target: Fix kref->refcount underflow in transport_cmd_finish_abort Greg Kroah-Hartman
2017-06-27 12:49 ` [PATCH 3.18 11/16] of: Add check to of_scan_flat_dt() before accessing initial_boot_params Greg Kroah-Hartman
2017-06-27 12:49 ` [PATCH 3.18 13/16] powerpc/slb: Force a full SLB flush when we insert for a bad EA Greg Kroah-Hartman
2017-06-27 12:49 ` [PATCH 3.18 14/16] usb: gadget: f_fs: avoid out of bounds access on comp_desc Greg Kroah-Hartman
2017-06-27 12:49 ` [PATCH 3.18 15/16] net: phy: fix marvell phy status reading Greg Kroah-Hartman
2017-06-27 12:49 ` [PATCH 3.18 16/16] mac80211/wpa: use constant time memory comparison for MACs Greg Kroah-Hartman
2017-06-27 18:58 ` [PATCH 3.18 00/16] 3.18.59-stable review Guenter Roeck
2017-06-28 13:51 ` Shuah Khan
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