@@ -1204,16 +1204,28 @@ __clear_user(void __user *addr, __kernel_size_t size)
{
__kernel_size_t res;
- might_fault();
- __asm__ __volatile__(
- "move\t$4, %1\n\t"
- "move\t$5, $0\n\t"
- "move\t$6, %2\n\t"
- __MODULE_JAL(__bzero)
- "move\t%0, $6"
- : "=r" (res)
- : "r" (addr), "r" (size)
- : "$4", "$5", "$6", __UA_t0, __UA_t1, "$31");
+ if (config_enabled(CONFIG_EVA) && segment_eq(get_fs(), get_ds())) {
+ __asm__ __volatile__(
+ "move\t$4, %1\n\t"
+ "move\t$5, $0\n\t"
+ "move\t$6, %2\n\t"
+ __MODULE_JAL(__bzero_kernel)
+ "move\t%0, $6"
+ : "=r" (res)
+ : "r" (addr), "r" (size)
+ : "$4", "$5", "$6", __UA_t0, __UA_t1, "$31");
+ } else {
+ might_fault();
+ __asm__ __volatile__(
+ "move\t$4, %1\n\t"
+ "move\t$5, $0\n\t"
+ "move\t$6, %2\n\t"
+ __MODULE_JAL(__bzero)
+ "move\t%0, $6"
+ : "=r" (res)
+ : "r" (addr), "r" (size)
+ : "$4", "$5", "$6", __UA_t0, __UA_t1, "$31");
+ }
return res;
}
@@ -17,6 +17,7 @@
#include <asm/fpu.h>
#include <asm/msa.h>
+extern void *__bzero_kernel(void *__s, size_t __count);
extern void *__bzero(void *__s, size_t __count);
extern long __strncpy_from_kernel_nocheck_asm(char *__to,
const char *__from, long __len);
@@ -66,6 +67,7 @@ EXPORT_SYMBOL(__copy_from_user_eva);
EXPORT_SYMBOL(__copy_in_user_eva);
EXPORT_SYMBOL(__copy_to_user_eva);
EXPORT_SYMBOL(__copy_user_inatomic_eva);
+EXPORT_SYMBOL(__bzero_kernel);
#endif
EXPORT_SYMBOL(__bzero);
EXPORT_SYMBOL(__strncpy_from_kernel_nocheck_asm);
@@ -238,6 +238,8 @@ LEAF(memset)
1:
#ifndef CONFIG_EVA
FEXPORT(__bzero)
+#else
+FEXPORT(__bzero_kernel)
#endif
__BUILD_BZERO LEGACY_MODE
This is a note to let you know that I have just added a patch titled MIPS: uaccess: Take EVA into account in [__]clear_user to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue This patch is scheduled to be released in version 3.16.7-ckt23. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.16.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ---8<------------------------------------------------------------ From 6c40f1d6abc18887b7cb6bb12badab86c5f36e15 Mon Sep 17 00:00:00 2001 From: James Hogan <james.hogan@imgtec.com> Date: Mon, 4 Jan 2016 20:29:04 +0000 Subject: MIPS: uaccess: Take EVA into account in [__]clear_user commit d6a428fb583738ad685c91a684748cdee7b2a05f upstream. __clear_user() (and clear_user() which uses it), always access the user mode address space, which results in EVA store instructions when EVA is enabled even if the current user address limit is KERNEL_DS. Fix this by adding a new symbol __bzero_kernel for the normal kernel address space bzero in EVA mode, and call that from __clear_user() if eva_kernel_access(). Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10844/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> [james.hogan@imgtec.com: backport] Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- arch/mips/include/asm/uaccess.h | 32 ++++++++++++++++++++++---------- arch/mips/kernel/mips_ksyms.c | 2 ++ arch/mips/lib/memset.S | 2 ++ 3 files changed, 26 insertions(+), 10 deletions(-)