diff options
| author | Masami Hiramatsu <mhiramat@kernel.org> | 2019-05-15 07:38:06 +0200 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2019-05-26 05:04:42 +0200 |
| commit | 2d8d8fac3b4eab035dcd0068e1f5a746a697fbb3 (patch) | |
| tree | 234b6d283e668d1a30772670e3e99af779a699cf | |
| parent | x86/ftrace: Make enable parameter bool where applicable (diff) | |
| download | linux-2d8d8fac3b4eab035dcd0068e1f5a746a697fbb3.tar.xz linux-2d8d8fac3b4eab035dcd0068e1f5a746a697fbb3.zip | |
x86/uaccess: Allow access_ok() in irq context if pagefault_disabled
WARN_ON_IN_IRQ() assumes that the access_ok() and following
user memory access can sleep. But this assumption is not
always correct; when the pagefault is disabled, following
memory access will just returns -EFAULT and never sleep.
Add pagefault_disabled() check in WARN_ON_ONCE() so that
it can ignore the case we call it with disabling pagefault.
For this purpose, this modified pagefault_disabled() as
an inline function.
Link: http://lkml.kernel.org/r/155789868664.26965.7932665824135793317.stgit@devnote2
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| -rw-r--r-- | arch/x86/include/asm/uaccess.h | 4 | ||||
| -rw-r--r-- | include/linux/uaccess.h | 5 |
2 files changed, 7 insertions, 2 deletions
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index c82abd6e4ca3..9c4435307ff8 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -66,7 +66,9 @@ static inline bool __chk_range_not_ok(unsigned long addr, unsigned long size, un }) #ifdef CONFIG_DEBUG_ATOMIC_SLEEP -# define WARN_ON_IN_IRQ() WARN_ON_ONCE(!in_task()) +static inline bool pagefault_disabled(void); +# define WARN_ON_IN_IRQ() \ + WARN_ON_ONCE(!in_task() && !pagefault_disabled()) #else # define WARN_ON_IN_IRQ() #endif diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h index 2b70130af585..5a43ef7db492 100644 --- a/include/linux/uaccess.h +++ b/include/linux/uaccess.h @@ -203,7 +203,10 @@ static inline void pagefault_enable(void) /* * Is the pagefault handler disabled? If so, user access methods will not sleep. */ -#define pagefault_disabled() (current->pagefault_disabled != 0) +static inline bool pagefault_disabled(void) +{ + return current->pagefault_disabled != 0; +} /* * The pagefault handler is in general disabled by pagefault_disable() or |