diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2016-11-22 10:57:15 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-11-15 17:13:11 +0100 |
| commit | ad8c619750c499f68f99f0bccb1a12114b7f2033 (patch) | |
| tree | 9c49a255b183bf134ed669cf0e396c37f78bf59e /arch | |
| parent | 44e0e2b47af248766bfe9395e50a3729fe81b018 (diff) | |
x86/uaccess, sched/preempt: Verify access_ok() context
commit 7c4788950ba5922fde976d80b72baf46f14dee8d upstream.
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>
[add include/preempt.h to fix build error - gregkh]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/uaccess.h | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index b8c75f3aade8..d788b0cdc0ad 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -7,6 +7,7 @@ #include <linux/compiler.h> #include <linux/thread_info.h> #include <linux/string.h> +#include <linux/preempt.h> #include <asm/asm.h> #include <asm/page.h> #include <asm/smap.h> @@ -66,6 +67,12 @@ 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 @@ -86,8 +93,11 @@ 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())); \ +}) /* * The exception table consists of pairs of addresses relative to the |