Jiang Lu 0de3b56b13 powerpc/oprofile: Disable pagefaults during user stack read ... A page fault occurred during reading user stack in oprofile backtrace would lead following calltrace: WARNING: at linux/kernel/smp.c:210 Modules linked in: CPU: 5 PID: 736 Comm: sh Tainted: G W 3.14.23-WR7.0.0.0_standard #1 task: c0000000f6208bc0 ti: c00000007c72c000 task.ti: c00000007c72c000 NIP: c0000000000ed6e4 LR: c0000000000ed5b8 CTR: 0000000000000000 REGS: c00000007c72f050 TRAP: 0700 Tainted: G W (3.14.23-WR7.0.0 tandard) MSR: 0000000080021000 <CE,ME> CR: 48222482 XER: 00000000 SOFTE: 0 GPR00: c0000000000ed5b8 c00000007c72f2d0 c0000000010aa048 0000000000000005 GPR04: c000000000fdb820 c00000007c72f410 0000000000000001 0000000000000005 GPR08: c0000000010b5768 c000000000f8a048 0000000000000001 0000000000000000 GPR12: 0000000048222482 c00000000fffe580 0000000022222222 0000000010129664 GPR16: 0000000010143cc0 0000000000000000 0000000044444444 0000000000000000 GPR20: c00000007c7221d8 c0000000f638e3c8 000003f15a20120d 0000000000000001 GPR24: 000000005a20120d c00000007c722000 c00000007cdedda8 00003fffef23b160 GPR28: 0000000000000001 c00000007c72f410 c000000000fdb820 0000000000000006 NIP [c0000000000ed6e4] .smp_call_function_single+0x18c/0x248 LR [c0000000000ed5b8] .smp_call_function_single+0x60/0x248 Call Trace: [c00000007c72f2d0] [c0000000000ed5b8] .smp_call_function_single+0x60/0x248 (unreliable) [c00000007c72f3a0] [c000000000030810] .__flush_tlb_page+0x164/0x1b0 [c00000007c72f460] [c00000000002e054] .ptep_set_access_flags+0xb8/0x168 [c00000007c72f500] [c0000000001ad3d8] .handle_mm_fault+0x4a8/0xbac [c00000007c72f5e0] [c000000000bb3238] .do_page_fault+0x3b8/0x868 [c00000007c72f810] [c00000000001e1d0] storage_fault_common+0x20/0x44 Exception: 301 at .__copy_tofrom_user_base+0x54/0x5b0 LR = .op_powerpc_backtrace+0x190/0x20c [c00000007c72fb00] [c000000000a2ec34] .op_powerpc_backtrace+0x204/0x20c (unreliable) [c00000007c72fbc0] [c000000000a2b5fc] .oprofile_add_ext_sample+0xe8/0x118 [c00000007c72fc70] [c000000000a2eee0] .fsl_emb_handle_interrupt+0x20c/0x27c [c00000007c72fd30] [c000000000a2e440] .op_handle_interrupt+0x44/0x58 [c00000007c72fdb0] [c000000000016d68] .performance_monitor_exception+0x74/0x90 [c00000007c72fe30] [c00000000001d8b4] exc_0x260_common+0xfc/0x100 performance_monitor_exception() is executed in a context with interrupt disabled and preemption enabled. When there is a user space page fault happened, do_page_fault() invoke in_atomic() to decide whether kernel should handle such page fault. in_atomic() only check preempt_count. So need call pagefault_disable() to disable preemption before reading user stack. Signed-off-by: Jiang Lu <lu.jiang@windriver.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>		2014-12-02 14:10:08 +11:00
..
boot	Merge remote-tracking branch 'scottwood/next' into next	2014-11-18 17:00:38 +11:00
configs	powerpc/config: Enable memory driver	2014-11-17 19:36:42 -06:00
crypto	powerpc: Fix compile of sha1-powerpc-asm.S on 32-bit	2013-03-05 16:56:26 +11:00
include	powerpc/powernv: Cleanup unused MCE definitions/declarations.	2014-12-02 11:03:45 +11:00
kernel	powerpc: Drop useless warning in eeh_init()	2014-12-02 11:03:45 +11:00
kvm	powerpc: Remove superfluous bootmem includes	2014-11-10 09:59:26 +11:00
lib	powerpc: Fix compilation of emulate_step()	2014-11-12 15:54:29 +11:00
math-emu	powerpc: Correct emulated mtfsf instruction	2014-04-07 10:33:11 +10:00
mm	powerpc/mm: Check for matching hpte without taking hpte lock	2014-12-02 11:03:45 +11:00
net	net: bpf: be friendly to kmemcheck	2014-09-09 16:58:56 -07:00
oprofile	powerpc/oprofile: Disable pagefaults during user stack read	2014-12-02 14:10:08 +11:00
perf	powerpc: Replace __get_cpu_var uses	2014-11-03 12:12:32 +11:00
platforms	powerpc/powernv: Cleanup unused MCE definitions/declarations.	2014-12-02 11:03:45 +11:00
sysdev	Merge remote-tracking branch 'scottwood/next' into next	2014-11-18 17:00:38 +11:00
xmon	powerpc/xmon: Fix build when 4xx=y and 44x=n	2014-11-12 16:54:54 +11:00
Kconfig	Merge remote-tracking branch 'scottwood/next' into next	2014-11-18 17:00:38 +11:00
Kconfig.debug	Patch queue for ppc - 2014-08-01	2014-08-05 09:58:11 +02:00
Makefile	powerpc: Add POWER8 CPU selection	2014-09-25 23:14:49 +10:00
relocs_check.pl	Fix warning typo "CONFIG_RELCOATABLE"	2013-05-29 15:11:30 +02:00