4.15-stable review patch. If anyone has any objections, please let me know.
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From: Dan Williams dan.j.williams@intel.com
commit b5c4ae4f35325d520b230bab6eb3310613b72ac1
In preparation for converting some __uaccess_begin() instances to __uacess_begin_nospec(), make sure all 'from user' uaccess paths are using the _begin(), _end() helpers rather than open-coded stac() and clac().
No functional changes.
Suggested-by: Ingo Molnar mingo@redhat.com Signed-off-by: Dan Williams dan.j.williams@intel.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Cc: linux-arch@vger.kernel.org Cc: Tom Lendacky thomas.lendacky@amd.com Cc: Kees Cook keescook@chromium.org Cc: kernel-hardening@lists.openwall.com Cc: gregkh@linuxfoundation.org Cc: Al Viro viro@zeniv.linux.org.uk Cc: torvalds@linux-foundation.org Cc: alan@linux.intel.com Link: https://lkml.kernel.org/r/151727416438.33451.17309465232057176966.stgit@dwil... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/lib/usercopy_32.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
--- a/arch/x86/lib/usercopy_32.c +++ b/arch/x86/lib/usercopy_32.c @@ -331,12 +331,12 @@ do { \
unsigned long __copy_user_ll(void *to, const void *from, unsigned long n) { - stac(); + __uaccess_begin(); if (movsl_is_ok(to, from, n)) __copy_user(to, from, n); else n = __copy_user_intel(to, from, n); - clac(); + __uaccess_end(); return n; } EXPORT_SYMBOL(__copy_user_ll); @@ -344,7 +344,7 @@ EXPORT_SYMBOL(__copy_user_ll); unsigned long __copy_from_user_ll_nocache_nozero(void *to, const void __user *from, unsigned long n) { - stac(); + __uaccess_begin(); #ifdef CONFIG_X86_INTEL_USERCOPY if (n > 64 && static_cpu_has(X86_FEATURE_XMM2)) n = __copy_user_intel_nocache(to, from, n); @@ -353,7 +353,7 @@ unsigned long __copy_from_user_ll_nocach #else __copy_user(to, from, n); #endif - clac(); + __uaccess_end(); return n; } EXPORT_SYMBOL(__copy_from_user_ll_nocache_nozero);