• Rabin Vincent's avatar
    tracing: Handle ftrace_dump() atomic context in graph_trace_open() · c130887c
    Rabin Vincent authored
    [ Upstream commit ef99b88b ]
    
    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: default avatarRabin Vincent <rabin@rab.in>
    Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
    Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
    c130887c
trace_functions_graph.c 39.4 KB