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authorJames Hogan <james.hogan@imgtec.com>2015-08-05 16:41:39 +0100
committerRalf Baechle <ralf@linux-mips.org>2015-12-22 11:58:43 +0100
commitd6a428fb583738ad685c91a684748cdee7b2a05f (patch)
treea0c987da5c8d66400b4cb40628921a775bc99ae8
parent6f06a2c45d8d714ea3b11a360b4a7191e52acaa4 (diff)
MIPS: uaccess: Take EVA into account in [__]clear_user
__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>
-rw-r--r--arch/mips/include/asm/uaccess.h32
-rw-r--r--arch/mips/kernel/mips_ksyms.c2
-rw-r--r--arch/mips/lib/memset.S2
3 files changed, 26 insertions, 10 deletions
diff --git a/arch/mips/include/asm/uaccess.h b/arch/mips/include/asm/uaccess.h
index 5014e187df23..2e3b3991cf0b 100644
--- a/arch/mips/include/asm/uaccess.h
+++ b/arch/mips/include/asm/uaccess.h
@@ -1235,16 +1235,28 @@ __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 (eva_kernel_access()) {
+ __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;
}
diff --git a/arch/mips/kernel/mips_ksyms.c b/arch/mips/kernel/mips_ksyms.c
index 291af0b5c482..e2b6ab74643d 100644
--- a/arch/mips/kernel/mips_ksyms.c
+++ b/arch/mips/kernel/mips_ksyms.c
@@ -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);
@@ -64,6 +65,7 @@ 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);
diff --git a/arch/mips/lib/memset.S b/arch/mips/lib/memset.S
index b8e63fd00375..8f0019a2e5c8 100644
--- a/arch/mips/lib/memset.S
+++ b/arch/mips/lib/memset.S
@@ -283,6 +283,8 @@ LEAF(memset)
1:
#ifndef CONFIG_EVA
FEXPORT(__bzero)
+#else
+FEXPORT(__bzero_kernel)
#endif
__BUILD_BZERO LEGACY_MODE