linux/arch
Steven Rostedt (VMware) a53276e282 x86/mm/ftrace: Do not bug in early boot on irqs_disabled in cpu_flush_range()
With function tracing starting in early bootup and having its trampoline
pages being read only, a bug triggered with the following:

kernel BUG at arch/x86/mm/pageattr.c:189!
invalid opcode: 0000 [#1] SMP
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 4.12.0-rc2-test+ #3
Hardware name: MSI MS-7823/CSM-H87M-G43 (MS-7823), BIOS V1.6 02/22/2014
task: ffffffffb4222500 task.stack: ffffffffb4200000
RIP: 0010:change_page_attr_set_clr+0x269/0x302
RSP: 0000:ffffffffb4203c88 EFLAGS: 00010046
RAX: 0000000000000046 RBX: 0000000000000000 RCX: 00000001b6000000
RDX: ffffffffb4203d40 RSI: 0000000000000000 RDI: ffffffffb4240d60
RBP: ffffffffb4203d18 R08: 00000001b6000000 R09: 0000000000000001
R10: ffffffffb4203aa8 R11: 0000000000000003 R12: ffffffffc029b000
R13: ffffffffb4203d40 R14: 0000000000000001 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff9a639ea00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff9a636b384000 CR3: 00000001ea21d000 CR4: 00000000000406b0
Call Trace:
 change_page_attr_clear+0x1f/0x21
 set_memory_ro+0x1e/0x20
 arch_ftrace_update_trampoline+0x207/0x21c
 ? ftrace_caller+0x64/0x64
 ? 0xffffffffc029b000
 ftrace_startup+0xf4/0x198
 register_ftrace_function+0x26/0x3c
 function_trace_init+0x5e/0x73
 tracer_init+0x1e/0x23
 tracing_set_tracer+0x127/0x15a
 register_tracer+0x19b/0x1bc
 init_function_trace+0x90/0x92
 early_trace_init+0x236/0x2b3
 start_kernel+0x200/0x3f5
 x86_64_start_reservations+0x29/0x2b
 x86_64_start_kernel+0x17c/0x18f
 secondary_startup_64+0x9f/0x9f
 ? secondary_startup_64+0x9f/0x9f

Interrupts should not be enabled at this early in the boot process. It is
also fine to leave interrupts enabled during this time as there's only one
CPU running, and on_each_cpu() means to only run on the current CPU.

If early_boot_irqs_disabled is set, it is safe to run cpu_flush_range() with
interrupts disabled. Don't trigger a BUG_ON() in that case.

Link: http://lkml.kernel.org/r/20170526093717.0be3b849@gandalf.local.home
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-05-26 22:37:01 -04:00
..
alpha osf_wait4(): fix infoleak 2017-05-21 13:10:07 -04:00
arc Kbuild UAPI header export updates for v4.12 2017-05-10 20:45:36 -07:00
arm KVM fixes for v4.12-rc2 2017-05-19 15:13:13 -07:00
arm64 KVM fixes for v4.12-rc2 2017-05-19 15:13:13 -07:00
blackfin uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
c6x uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
cris devicetree: Move include prefixes from arch to separate directory 2017-05-18 23:55:48 -07:00
frv Kbuild UAPI header export updates for v4.12 2017-05-10 20:45:36 -07:00
h8300 uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
hexagon uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
ia64 Kbuild UAPI header export updates for v4.12 2017-05-10 20:45:36 -07:00
m32r uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
m68k uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
metag devicetree: Move include prefixes from arch to separate directory 2017-05-18 23:55:48 -07:00
microblaze uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
mips devicetree: Move include prefixes from arch to separate directory 2017-05-18 23:55:48 -07:00
mn10300 uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
nios2 nios2 update for v4.12-rc1 2017-05-12 09:53:16 -07:00
openrisc uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
parisc uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
powerpc KVM fixes for v4.12-rc2 2017-05-19 15:13:13 -07:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2017-05-16 09:24:44 -07:00
score uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
sh Kbuild UAPI header export updates for v4.12 2017-05-10 20:45:36 -07:00
sparc sparc/ftrace: Fix ftrace graph time measurement 2017-05-17 12:07:47 -07:00
tile arch/include: remove empty Kbuild files 2017-05-11 00:22:18 +09:00
um Merge branch 'for-linus-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml 2017-05-13 10:20:02 -07:00
unicore32 Kbuild UAPI header export updates for v4.12 2017-05-10 20:45:36 -07:00
x86 x86/mm/ftrace: Do not bug in early boot on irqs_disabled in cpu_flush_range() 2017-05-26 22:37:01 -04:00
xtensa uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
.gitignore
Kconfig Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-05-10 10:30:46 -07:00