Ralf Baechle cf5b2d23a7 MIPS: oprofile: Fix BUG due to smp_processor_id() in preemptible code. ... current_cpu_type() is not preemption-safe. If CONFIG_PREEMPT is enabled then mipsxx_reg_setup() can be called from preemptible state. Added get_cpu()/put_cpu() pair to make it preemption-safe. This was found while testing oprofile with CONFIG_DEBUG_PREEMPT enable. /usr/zntestsuite # opcontrol --init /usr/zntestsuite # opcontrol --setup --event=L2_CACHE_ACCESSES:500 --event=L2_CACHE_MISSES:500 --no-vmlinux /usr/zntestsuite # opcontrol --start Using 2.6+ OProfile kernel interface. BUG: using smp_processor_id() in preemptible [00000000] code: oprofiled/1362 caller is mipsxx_reg_setup+0x11c/0x164 CPU: 0 PID: 1362 Comm: oprofiled Not tainted 3.10.4 #18 Stack : 00000006 70757465 00000000 00000000 00000000 00000000 80b173f6 00000037 80b10000 00000000 80b21614 88f5a220 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 89c49c00 89c49c2c 80721254 807b7927 8012c1d0 80b10000 80721254 00000000 00000552 88f5a220 80b1335c 807b78e6 89c49ba8 ... Call Trace: [<801099a4>] show_stack+0x64/0x7c [<80665520>] dump_stack+0x20/0x2c [<803a2250>] debug_smp_processor_id+0xe0/0xf0 [<8052df24>] mipsxx_reg_setup+0x11c/0x164 [<8052cd70>] op_mips_setup+0x24/0x4c [<80529cfc>] oprofile_setup+0x5c/0x12c [<8052b9f8>] event_buffer_open+0x78/0xf8 [<801c3150>] do_dentry_open.isra.15+0x2b8/0x3b0 [<801c3270>] finish_open+0x28/0x4c [<801d49b8>] do_last.isra.41+0x2cc/0xd00 [<801d54a0>] path_openat+0xb4/0x4c4 [<801d5c44>] do_filp_open+0x3c/0xac [<801c4744>] do_sys_open+0x110/0x1f4 [<8010f47c>] stack_done+0x20/0x44 Bug reported and original patch by Jerin Jacob <jerinjacobk@gmail.com>. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Acked-by: Jerin Jacob <jerinjacobk@gmail.com>		2013-08-05 13:34:22 +02:00
..
asm	MIPS: oprofile: Fix BUG due to smp_processor_id() in preemptible code.	2013-08-05 13:34:22 +02:00
uapi/asm	MIPS: uapi/asm/siginfo.h: Fix GCC 4.1.2 compilation	2013-07-30 18:40:40 +02:00