3.16.7-ckt18 -stable review patch. If anyone has any objections, please let me know.
------------------ From: Yann Droneaud <[email protected]> commit ebf2d2689de551d90965090bb991fc640a0c0d41 upstream. Commit 0a196848ca36 ("perf: Fix arch_perf_out_copy_user default"), changes copy_from_user_nmi() to return the number of remaining bytes so that it behave like copy_from_user(). Unfortunately, when the range is outside of the process memory, the return value is still the number of byte copied, eg. 0, instead of the remaining bytes. As all users of copy_from_user_nmi() were modified as part of commit 0a196848ca36, the function should be fixed to return the total number of bytes if range is not correct. Signed-off-by: Yann Droneaud <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> Cc: Yann Droneaud <[email protected]> Signed-off-by: Luis Henriques <[email protected]> --- arch/x86/lib/usercopy.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/lib/usercopy.c b/arch/x86/lib/usercopy.c index ddf9ecb53cc3..e342586db6e4 100644 --- a/arch/x86/lib/usercopy.c +++ b/arch/x86/lib/usercopy.c @@ -20,7 +20,7 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n) unsigned long ret; if (__range_not_ok(from, n, TASK_SIZE)) - return 0; + return n; /* * Even though this function is typically called from NMI/IRQ context -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
