path: root/arch/alpha/lib
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authorWill Deacon <>2013-09-10 10:58:12 +0100
committerMatt Turner <>2013-11-16 16:37:10 -0800
commit6e22f8f2e8d81dcab4c40bc229d53388fda63dbc (patch)
treea06cbec1bfd358372db2647fafe847204d51ebe7 /arch/alpha/lib
parent4914d7b458e35a7db2f9c7dc6eb014620254bbbf (diff)
alpha: perf: fix out-of-bounds array access triggered from raw event
Vince's perf fuzzer uncovered the following issue on Alpha: Unable to handle kernel paging request at virtual address fffffbfe4e46a0e8 CPU 0 perf_fuzzer(1278): Oops 0 pc = [<fffffc000031fbc0>] ra = [<fffffc000031ff54>] ps = 0007 Not tainted pc is at alpha_perf_event_set_period+0x60/0xf0 ra is at alpha_pmu_enable+0x1a4/0x1c0 v0 = 0000000000000000 t0 = 00000000000fffff t1 = fffffc007b3f5800 t2 = fffffbff275faa94 t3 = ffffffffc9b9bd89 t4 = fffffbfe4e46a098 t5 = 0000000000000020 t6 = fffffbfe4e46a0b8 t7 = fffffc007f4c8000 s0 = 0000000000000000 s1 = fffffc0001b0c018 s2 = fffffc0001b0c020 s3 = fffffc007b3f5800 s4 = 0000000000000001 s5 = ffffffffc9b9bd85 s6 = 0000000000000001 a0 = 0000000000000006 a1 = fffffc007b3f5908 a2 = fffffbfe4e46a098 a3 = 00000005000108c0 a4 = 0000000000000000 a5 = 0000000000000000 t8 = 0000000000000001 t9 = 0000000000000001 t10= 0000000027829f6f t11= 0000000000000020 pv = fffffc000031fb60 at = fffffc0000950900 gp = fffffc0000940900 sp = fffffc007f4cbca8 Disabling lock debugging due to kernel taint Trace: [<fffffc000031ff54>] alpha_pmu_enable+0x1a4/0x1c0 [<fffffc000039f4e8>] perf_pmu_enable+0x48/0x60 [<fffffc00003a0d6c>] __perf_install_in_context+0x15c/0x230 [<fffffc000039d1f0>] remote_function+0x80/0xa0 [<fffffc00003a0c10>] __perf_install_in_context+0x0/0x230 [<fffffc000037b7e4>] smp_call_function_single+0x1b4/0x1d0 [<fffffc000039bb70>] task_function_call+0x60/0x80 [<fffffc00003a0c10>] __perf_install_in_context+0x0/0x230 [<fffffc000039bb44>] task_function_call+0x34/0x80 [<fffffc000039d3fc>] perf_install_in_context+0x9c/0x150 [<fffffc00003a0c10>] __perf_install_in_context+0x0/0x230 [<fffffc00003a5100>] SYSC_perf_event_open+0x360/0xac0 [<fffffc00003110c4>] entSys+0xa4/0xc0 This is due to the raw event encoding being used as an index directly into the ev67_mapping array, rather than being validated against the ev67_pmc_event_type enumeration instead. Unlike other architectures, which allow raw events to propagate into the hardware counters with little interference, the limited number of events on Alpha and the strict event <-> counter relationships mean that raw events actually correspond to the Linux-specific Alpha events, rather than anything defined by the architecture. This patch adds a new callback to alpha_pmu_t for validating the raw event encoding with the Linux event types for the PMU, preventing the out-of-bounds array access. Cc: Peter Zijlstra <> Acked-by: Michael Cree <> Acked-by: Matt Turner <> Signed-off-by: Will Deacon <>
Diffstat (limited to 'arch/alpha/lib')
0 files changed, 0 insertions, 0 deletions