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| author | Peter Zijlstra <peterz@infradead.org> | 2016-11-22 10:57:15 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-12-06 10:32:40 +0100 |
| commit | 7c4788950ba5922fde976d80b72baf46f14dee8d (patch) | |
| tree | 71f081928406571e40f14f8fa2f5a54788933083 /arch | |
| parent | sched/x86: Make CONFIG_SCHED_MC_PRIO=y easier to enable (diff) | |
| download | linux-7c4788950ba5922fde976d80b72baf46f14dee8d.tar.xz linux-7c4788950ba5922fde976d80b72baf46f14dee8d.zip | |
x86/uaccess, sched/preempt: Verify access_ok() context
I recently encountered wreckage because access_ok() was used where it
should not be, add an explicit WARN when access_ok() is used wrongly.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/uaccess.h | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index faf3687f1035..ea148313570f 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -68,6 +68,12 @@ static inline bool __chk_range_not_ok(unsigned long addr, unsigned long size, un __chk_range_not_ok((unsigned long __force)(addr), size, limit); \ }) +#ifdef CONFIG_DEBUG_ATOMIC_SLEEP +# define WARN_ON_IN_IRQ() WARN_ON_ONCE(!in_task()) +#else +# define WARN_ON_IN_IRQ() +#endif + /** * access_ok: - Checks if a user space pointer is valid * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that @@ -88,8 +94,11 @@ static inline bool __chk_range_not_ok(unsigned long addr, unsigned long size, un * checks that the pointer is in the user space range - after calling * this function, memory access functions may still return -EFAULT. */ -#define access_ok(type, addr, size) \ - likely(!__range_not_ok(addr, size, user_addr_max())) +#define access_ok(type, addr, size) \ +({ \ + WARN_ON_IN_IRQ(); \ + likely(!__range_not_ok(addr, size, user_addr_max())); \ +}) /* * These are the main single-value transfer routines. They automatically |