From d755209f6afddecfb1bb33efebb2a87039959205 Mon Sep 17 00:00:00 2001 From: Suzuki K Poulose Date: Mon, 5 Jun 2017 14:15:04 -0600 Subject: [PATCH] coresight: etm_perf: Fix using uninitialised work With 4.11-rc4, the following command triggers a WARN_ON, when a sink is not enabled. perf record -e cs_etm/@20010000.etf/ [88286.547741] ------------[ cut here ]------------ [88286.552332] WARNING: CPU: 3 PID: 2156 at kernel/workqueue.c:1442 __queue_work+0x29c/0x3b8 [88286.560427] Modules linked in: [88286.563451] [88286.564928] CPU: 3 PID: 2156 Comm: perf_v4.11 Not tainted 4.11.0-rc4 #217 [88286.573453] Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Aug 15 2016 [88286.584128] task: ffff80097597c200 task.stack: ffff8009768b0000 [88286.589990] PC is at __queue_work+0x29c/0x3b8 [88286.594303] LR is at __queue_work+0x104/0x3b8 [88286.598614] pc : [] lr : [] pstate: a00001c5 [88286.605934] sp : ffff8009768b3aa0 [88286.609212] x29: ffff8009768b3aa0 x28: ffff80097ff3da00 [88286.614477] x27: ffff80097ff89c00 x26: ffff8009751b0e00 [88286.619741] x25: ffff000008c9f000 x24: 0000000000000003 [88286.625004] x23: 0000000000000040 x22: ffff000008d3dab8 [88286.630268] x21: ffff800977804400 x20: 0000000000000007 [88286.635532] x19: ffff000008c54000 x18: 0000fffff9185160 [88286.640795] x17: 0000ffffb33d9a38 x16: ffff000008088270 [88286.646059] x15: 0000ffffb345b590 x14: 0000000000000000 [88286.651322] x13: 0000000000000004 x12: 0000000000000040 [88286.656586] x11: 0000000000000068 x10: 0000000000000000 [88286.661849] x9 : ffff800977400028 x8 : 0000000000000000 [88286.667113] x7 : 0000000000000000 x6 : ffff0000080d8ae4 [88286.672376] x5 : 0000000000000000 x4 : 0000000000000080 [88286.677639] x3 : 0000000000000000 x2 : 0000000000000000 [88286.682903] x1 : 0000000000000000 x0 : ffff8009751b0e08 [88286.688166] [88286.689638] ---[ end trace 31633f18fd33d4cb ]--- [88286.694206] Call trace: [88286.696627] Exception stack(0xffff8009768b38d0 to 0xffff8009768b3a00) [88286.703004] 38c0: ffff000008c54000 0001000000000000 [88286.710757] 38e0: ffff8009768b3aa0 ffff0000080d8c7c ffff8009768b3b50 ffff80097ff8a5b0 [88286.718511] 3900: 0000800977325000 0000000000000000 0000000000000040 ffff80097ffc6180 [88286.726264] 3920: ffff8009768b3940 ffff0000088a8694 ffff80097ffc5800 0000000000000000 [88286.734017] 3940: ffff8009768b3960 ffff0000081919c0 ffff80097ffc5280 0000000000000001 [88286.741771] 3960: ffff8009768b3a50 ffff00000819206c ffff8009751b0e08 0000000000000000 [88286.749523] 3980: 0000000000000000 0000000000000000 0000000000000080 0000000000000000 [88286.757277] 39a0: ffff0000080d8ae4 0000000000000000 0000000000000000 ffff800977400028 [88286.765029] 39c0: 0000000000000000 0000000000000068 0000000000000040 0000000000000004 [88286.772783] 39e0: 0000000000000000 0000ffffb345b590 ffff000008088270 0000ffffb33d9a38 [88286.780537] [] __queue_work+0x29c/0x3b8 [88286.785883] [] queue_work_on+0x60/0x78 [88286.791146] [] etm_setup_aux+0x178/0x238 [88286.796578] [] rb_alloc_aux+0x228/0x310 [88286.801925] [] perf_mmap+0x404/0x5a8 [88286.807015] [] mmap_region+0x394/0x5c0 [88286.812276] [] do_mmap+0x254/0x388 [88286.817191] [] vm_mmap_pgoff+0xbc/0xe0 [88286.822452] [] SyS_mmap_pgoff+0xac/0x228 [88286.827884] [] sys_mmap+0x18/0x28 [88286.832714] [] el0_svc_naked+0x24/0x28 The patch makes sure that the event_data->work is initialised properly before we could possibly use it. Cc: Mathieu Poirier Signed-off-by: Suzuki K Poulose Tested-by: Mike Leach Signed-off-by: Mathieu Poirier Signed-off-by: Greg Kroah-Hartman --- drivers/hwtracing/coresight/coresight-etm-perf.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c index 288a423c1b27..8f546f59a3fd 100644 --- a/drivers/hwtracing/coresight/coresight-etm-perf.c +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c @@ -201,6 +201,7 @@ static void *etm_setup_aux(int event_cpu, void **pages, event_data = alloc_event_data(event_cpu); if (!event_data) return NULL; + INIT_WORK(&event_data->work, free_event_data); /* * In theory nothing prevent tracers in a trace session from being @@ -217,8 +218,6 @@ static void *etm_setup_aux(int event_cpu, void **pages, if (!sink) goto err; - INIT_WORK(&event_data->work, free_event_data); - mask = &event_data->mask; /* Setup the path for each CPU in a trace session */