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| author | Rabin Vincent <rabin@rab.in> | 2015-04-13 22:30:12 +0200 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2015-04-16 09:32:17 -0400 |
| commit | ef99b88b16bee753fa51207abdc58ae660453ec6 (patch) | |
| tree | b99397fb7362af443021f72ed569ad76476701c3 /kernel | |
| parent | 9828413d4715d4ed12bc92b161f4ed377d777ffb (diff) | |
| download | lwn-ef99b88b16bee753fa51207abdc58ae660453ec6.tar.gz lwn-ef99b88b16bee753fa51207abdc58ae660453ec6.zip | |
tracing: Handle ftrace_dump() atomic context in graph_trace_open()
graph_trace_open() can be called in atomic context from ftrace_dump().
Use GFP_ATOMIC for the memory allocations when that's the case, in order
to avoid the following splat.
BUG: sleeping function called from invalid context at mm/slab.c:2849
in_atomic(): 1, irqs_disabled(): 128, pid: 0, name: swapper/0
Backtrace:
..
[<8004dc94>] (__might_sleep) from [<801371f4>] (kmem_cache_alloc_trace+0x160/0x238)
r7:87800040 r6:000080d0 r5:810d16e8 r4:000080d0
[<80137094>] (kmem_cache_alloc_trace) from [<800cbd60>] (graph_trace_open+0x30/0xd0)
r10:00000100 r9:809171a8 r8:00008e28 r7:810d16f0 r6:00000001 r5:810d16e8
r4:810d16f0
[<800cbd30>] (graph_trace_open) from [<800c79c4>] (trace_init_global_iter+0x50/0x9c)
r8:00008e28 r7:808c853c r6:00000001 r5:810d16e8 r4:810d16f0 r3:800cbd30
[<800c7974>] (trace_init_global_iter) from [<800c7aa0>] (ftrace_dump+0x90/0x2ec)
r4:810d2580 r3:00000000
[<800c7a10>] (ftrace_dump) from [<80414b2c>] (sysrq_ftrace_dump+0x1c/0x20)
r10:00000100 r9:809171a8 r8:808f6e7c r7:00000001 r6:00000007 r5:0000007a
r4:808d5394
[<80414b10>] (sysrq_ftrace_dump) from [<800169b8>] (return_to_handler+0x0/0x18)
[<80415498>] (__handle_sysrq) from [<800169b8>] (return_to_handler+0x0/0x18)
r8:808c8100 r7:808c8444 r6:00000101 r5:00000010 r4:84eb3210
[<80415668>] (handle_sysrq) from [<800169b8>] (return_to_handler+0x0/0x18)
[<8042a760>] (pl011_int) from [<800169b8>] (return_to_handler+0x0/0x18)
r10:809171bc r9:809171a8 r8:00000001 r7:00000026 r6:808c6000 r5:84f01e60
r4:8454fe00
[<8007782c>] (handle_irq_event_percpu) from [<80077b44>] (handle_irq_event+0x4c/0x6c)
r10:808c7ef0 r9:87283e00 r8:00000001 r7:00000000 r6:8454fe00 r5:84f01e60
r4:84f01e00
[<80077af8>] (handle_irq_event) from [<8007aa28>] (handle_fasteoi_irq+0xf0/0x1ac)
r6:808f52a4 r5:84f01e60 r4:84f01e00 r3:00000000
[<8007a938>] (handle_fasteoi_irq) from [<80076dc0>] (generic_handle_irq+0x3c/0x4c)
r6:00000026 r5:00000000 r4:00000026 r3:8007a938
[<80076d84>] (generic_handle_irq) from [<80077128>] (__handle_domain_irq+0x8c/0xfc)
r4:808c1e38 r3:0000002e
[<8007709c>] (__handle_domain_irq) from [<800087b8>] (gic_handle_irq+0x34/0x6c)
r10:80917748 r9:00000001 r8:88802100 r7:808c7ef0 r6:808c8fb0 r5:00000015
r4:8880210c r3:808c7ef0
[<80008784>] (gic_handle_irq) from [<80014044>] (__irq_svc+0x44/0x7c)
Link: http://lkml.kernel.org/r/1428953721-31349-1-git-send-email-rabin@rab.in
Link: http://lkml.kernel.org/r/1428957012-2319-1-git-send-email-rabin@rab.in
Cc: stable@vger.kernel.org # 3.13+
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/trace_functions_graph.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index 2d25ad1526bb..b6fce365ef27 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -1309,15 +1309,19 @@ void graph_trace_open(struct trace_iterator *iter) { /* pid and depth on the last trace processed */ struct fgraph_data *data; + gfp_t gfpflags; int cpu; iter->private = NULL; - data = kzalloc(sizeof(*data), GFP_KERNEL); + /* We can be called in atomic context via ftrace_dump() */ + gfpflags = (in_atomic() || irqs_disabled()) ? GFP_ATOMIC : GFP_KERNEL; + + data = kzalloc(sizeof(*data), gfpflags); if (!data) goto out_err; - data->cpu_data = alloc_percpu(struct fgraph_cpu_data); + data->cpu_data = alloc_percpu_gfp(struct fgraph_cpu_data, gfpflags); if (!data->cpu_data) goto out_err_free; |