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| author | James Hogan <james.hogan@imgtec.com> | 2016-01-04 23:29:04 +0300 |
|---|---|---|
| committer | Luis Henriques <luis.henriques@canonical.com> | 2016-01-25 13:43:31 +0300 |
| commit | fbd67708d60c17caae404e88dce3b33d9063dee6 (patch) | |
| tree | b1359ed5b4f40cc9a6c9180b9abe2c224ef6a71a | |
| parent | 029692a0ed928b0dcf3b0eab0436295eb663b6e4 (diff) | |
| download | linux-fbd67708d60c17caae404e88dce3b33d9063dee6.tar.xz | |
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>
| -rw-r--r-- | arch/mips/include/asm/uaccess.h | 32 | ||||
| -rw-r--r-- | arch/mips/kernel/mips_ksyms.c | 2 | ||||
| -rw-r--r-- | arch/mips/lib/memset.S | 2 |
3 files changed, 26 insertions, 10 deletions
diff --git a/arch/mips/include/asm/uaccess.h b/arch/mips/include/asm/uaccess.h index 81d4d7e012ca..681331257bac 100644 --- a/arch/mips/include/asm/uaccess.h +++ b/arch/mips/include/asm/uaccess.h @@ -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; } diff --git a/arch/mips/kernel/mips_ksyms.c b/arch/mips/kernel/mips_ksyms.c index 1b2452e2be67..c1e152a27b17 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); @@ -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); diff --git a/arch/mips/lib/memset.S b/arch/mips/lib/memset.S index 7b0e5462ca51..fd83406ceccc 100644 --- a/arch/mips/lib/memset.S +++ b/arch/mips/lib/memset.S @@ -238,6 +238,8 @@ LEAF(memset) 1: #ifndef CONFIG_EVA FEXPORT(__bzero) +#else +FEXPORT(__bzero_kernel) #endif __BUILD_BZERO LEGACY_MODE |