From: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> To: Michael Ellerman <mpe@ellerman.id.au>, Steven Rostedt <rostedt@goodmis.org> Cc: Nicholas Piggin <npiggin@gmail.com>, <linux-kernel@vger.kernel.org>, <linuxppc-dev@lists.ozlabs.org> Subject: [PATCH 3/3] powerpc: Use ftrace_graph_ret_addr() when unwinding Date: Thu, 5 Sep 2019 23:50:30 +0530 [thread overview] Message-ID: <dc89c9a887121342d9c7819482c3dabdece2a323.1567707399.git.naveen.n.rao@linux.vnet.ibm.com> (raw) In-Reply-To: <cover.1567707399.git.naveen.n.rao@linux.vnet.ibm.com> With support for HAVE_FUNCTION_GRAPH_RET_ADDR_PTR, ftrace_graph_ret_addr() provides more robust unwinding when function graph is in use. Update show_stack() to use the same. With dump_stack() added to sysrq_sysctl_handler(), before this patch: root@(none):/sys/kernel/debug/tracing# cat /proc/sys/kernel/sysrq CPU: 0 PID: 218 Comm: cat Not tainted 5.3.0-rc7-00868-g8453ad4a078c-dirty #20 Call Trace: [c0000000d1e13c30] [c00000000006ab98] return_to_handler+0x0/0x40 (dump_stack+0xe8/0x164) (unreliable) [c0000000d1e13c80] [c000000000145680] sysrq_sysctl_handler+0x48/0xb8 [c0000000d1e13cd0] [c00000000006ab98] return_to_handler+0x0/0x40 (proc_sys_call_handler+0x274/0x2a0) [c0000000d1e13d60] [c00000000006ab98] return_to_handler+0x0/0x40 (return_to_handler+0x0/0x40) [c0000000d1e13d80] [c00000000006ab98] return_to_handler+0x0/0x40 (__vfs_read+0x3c/0x70) [c0000000d1e13dd0] [c00000000006ab98] return_to_handler+0x0/0x40 (vfs_read+0xb8/0x1b0) [c0000000d1e13e20] [c00000000006ab98] return_to_handler+0x0/0x40 (ksys_read+0x7c/0x140) After this patch: Call Trace: [c0000000d1e33c30] [c00000000006ab58] return_to_handler+0x0/0x40 (dump_stack+0xe8/0x164) (unreliable) [c0000000d1e33c80] [c000000000145680] sysrq_sysctl_handler+0x48/0xb8 [c0000000d1e33cd0] [c00000000006ab58] return_to_handler+0x0/0x40 (proc_sys_call_handler+0x274/0x2a0) [c0000000d1e33d60] [c00000000006ab58] return_to_handler+0x0/0x40 (__vfs_read+0x3c/0x70) [c0000000d1e33d80] [c00000000006ab58] return_to_handler+0x0/0x40 (vfs_read+0xb8/0x1b0) [c0000000d1e33dd0] [c00000000006ab58] return_to_handler+0x0/0x40 (ksys_read+0x7c/0x140) [c0000000d1e33e20] [c00000000006ab58] return_to_handler+0x0/0x40 (system_call+0x5c/0x68) Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> --- arch/powerpc/kernel/process.c | 19 ++++++------------- 1 file changed, 6 insertions(+), 13 deletions(-) diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 24621e7e5033..f289bdd2b562 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -2047,10 +2047,8 @@ void show_stack(struct task_struct *tsk, unsigned long *stack) int count = 0; int firstframe = 1; #ifdef CONFIG_FUNCTION_GRAPH_TRACER - struct ftrace_ret_stack *ret_stack; - extern void return_to_handler(void); - unsigned long rth = (unsigned long)return_to_handler; - int curr_frame = 0; + unsigned long ret_addr; + int ftrace_idx = 0; #endif if (tsk == NULL) @@ -2079,15 +2077,10 @@ void show_stack(struct task_struct *tsk, unsigned long *stack) if (!firstframe || ip != lr) { printk("["REG"] ["REG"] %pS", sp, ip, (void *)ip); #ifdef CONFIG_FUNCTION_GRAPH_TRACER - if ((ip == rth) && curr_frame >= 0) { - ret_stack = ftrace_graph_get_ret_stack(current, - curr_frame++); - if (ret_stack) - pr_cont(" (%pS)", - (void *)ret_stack->ret); - else - curr_frame = -1; - } + ret_addr = ftrace_graph_ret_addr(current, + &ftrace_idx, ip, stack); + if (ret_addr != ip) + pr_cont(" (%pS)", (void *)ret_addr); #endif if (firstframe) pr_cont(" (unreliable)"); -- 2.23.0
WARNING: multiple messages have this Message-ID (diff)
From: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> To: Michael Ellerman <mpe@ellerman.id.au>, Steven Rostedt <rostedt@goodmis.org> Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Nicholas Piggin <npiggin@gmail.com> Subject: [PATCH 3/3] powerpc: Use ftrace_graph_ret_addr() when unwinding Date: Thu, 5 Sep 2019 23:50:30 +0530 [thread overview] Message-ID: <dc89c9a887121342d9c7819482c3dabdece2a323.1567707399.git.naveen.n.rao@linux.vnet.ibm.com> (raw) In-Reply-To: <cover.1567707399.git.naveen.n.rao@linux.vnet.ibm.com> With support for HAVE_FUNCTION_GRAPH_RET_ADDR_PTR, ftrace_graph_ret_addr() provides more robust unwinding when function graph is in use. Update show_stack() to use the same. With dump_stack() added to sysrq_sysctl_handler(), before this patch: root@(none):/sys/kernel/debug/tracing# cat /proc/sys/kernel/sysrq CPU: 0 PID: 218 Comm: cat Not tainted 5.3.0-rc7-00868-g8453ad4a078c-dirty #20 Call Trace: [c0000000d1e13c30] [c00000000006ab98] return_to_handler+0x0/0x40 (dump_stack+0xe8/0x164) (unreliable) [c0000000d1e13c80] [c000000000145680] sysrq_sysctl_handler+0x48/0xb8 [c0000000d1e13cd0] [c00000000006ab98] return_to_handler+0x0/0x40 (proc_sys_call_handler+0x274/0x2a0) [c0000000d1e13d60] [c00000000006ab98] return_to_handler+0x0/0x40 (return_to_handler+0x0/0x40) [c0000000d1e13d80] [c00000000006ab98] return_to_handler+0x0/0x40 (__vfs_read+0x3c/0x70) [c0000000d1e13dd0] [c00000000006ab98] return_to_handler+0x0/0x40 (vfs_read+0xb8/0x1b0) [c0000000d1e13e20] [c00000000006ab98] return_to_handler+0x0/0x40 (ksys_read+0x7c/0x140) After this patch: Call Trace: [c0000000d1e33c30] [c00000000006ab58] return_to_handler+0x0/0x40 (dump_stack+0xe8/0x164) (unreliable) [c0000000d1e33c80] [c000000000145680] sysrq_sysctl_handler+0x48/0xb8 [c0000000d1e33cd0] [c00000000006ab58] return_to_handler+0x0/0x40 (proc_sys_call_handler+0x274/0x2a0) [c0000000d1e33d60] [c00000000006ab58] return_to_handler+0x0/0x40 (__vfs_read+0x3c/0x70) [c0000000d1e33d80] [c00000000006ab58] return_to_handler+0x0/0x40 (vfs_read+0xb8/0x1b0) [c0000000d1e33dd0] [c00000000006ab58] return_to_handler+0x0/0x40 (ksys_read+0x7c/0x140) [c0000000d1e33e20] [c00000000006ab58] return_to_handler+0x0/0x40 (system_call+0x5c/0x68) Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> --- arch/powerpc/kernel/process.c | 19 ++++++------------- 1 file changed, 6 insertions(+), 13 deletions(-) diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 24621e7e5033..f289bdd2b562 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -2047,10 +2047,8 @@ void show_stack(struct task_struct *tsk, unsigned long *stack) int count = 0; int firstframe = 1; #ifdef CONFIG_FUNCTION_GRAPH_TRACER - struct ftrace_ret_stack *ret_stack; - extern void return_to_handler(void); - unsigned long rth = (unsigned long)return_to_handler; - int curr_frame = 0; + unsigned long ret_addr; + int ftrace_idx = 0; #endif if (tsk == NULL) @@ -2079,15 +2077,10 @@ void show_stack(struct task_struct *tsk, unsigned long *stack) if (!firstframe || ip != lr) { printk("["REG"] ["REG"] %pS", sp, ip, (void *)ip); #ifdef CONFIG_FUNCTION_GRAPH_TRACER - if ((ip == rth) && curr_frame >= 0) { - ret_stack = ftrace_graph_get_ret_stack(current, - curr_frame++); - if (ret_stack) - pr_cont(" (%pS)", - (void *)ret_stack->ret); - else - curr_frame = -1; - } + ret_addr = ftrace_graph_ret_addr(current, + &ftrace_idx, ip, stack); + if (ret_addr != ip) + pr_cont(" (%pS)", (void *)ret_addr); #endif if (firstframe) pr_cont(" (unreliable)"); -- 2.23.0
next prev parent reply other threads:[~2019-09-05 18:21 UTC|newest] Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-09-05 18:20 [PATCH 0/3] powerpc/ftrace: Enable HAVE_FUNCTION_GRAPH_RET_ADDR_PTR Naveen N. Rao 2019-09-05 18:20 ` Naveen N. Rao 2019-09-05 18:20 ` [PATCH 1/3] ftrace: Look up the address of return_to_handler() using helpers Naveen N. Rao 2019-09-05 18:20 ` Naveen N. Rao 2019-09-19 10:25 ` Michael Ellerman 2019-09-05 18:20 ` [PATCH 2/3] powerpc/ftrace: Enable HAVE_FUNCTION_GRAPH_RET_ADDR_PTR Naveen N. Rao 2019-09-05 18:20 ` Naveen N. Rao 2019-09-05 18:20 ` Naveen N. Rao [this message] 2019-09-05 18:20 ` [PATCH 3/3] powerpc: Use ftrace_graph_ret_addr() when unwinding Naveen N. Rao 2019-09-08 10:25 ` [PATCH 0/3] powerpc/ftrace: Enable HAVE_FUNCTION_GRAPH_RET_ADDR_PTR Nicholas Piggin 2019-09-08 10:25 ` Nicholas Piggin
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=dc89c9a887121342d9c7819482c3dabdece2a323.1567707399.git.naveen.n.rao@linux.vnet.ibm.com \ --to=naveen.n.rao@linux.vnet.ibm.com \ --cc=linux-kernel@vger.kernel.org \ --cc=linuxppc-dev@lists.ozlabs.org \ --cc=mpe@ellerman.id.au \ --cc=npiggin@gmail.com \ --cc=rostedt@goodmis.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: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.