Re: [PATCH v1 01/15] powerpc/uaccess: Remove __get_user_allowed() and unsafe_op_wrap()
From: Daniel Axtens <hidden>
Date: 2021-03-02 07:11:32
Also in:
lkml
Christophe Leroy [off-list ref] writes:
quoted hunk ↗ jump to hunk
Those two macros have only one user which is unsafe_get_user(). Put everything in one place and remove them. Signed-off-by: Christophe Leroy <redacted> --- arch/powerpc/include/asm/uaccess.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h index 78e2a3990eab..8cbf3e3874f1 100644 --- a/arch/powerpc/include/asm/uaccess.h +++ b/arch/powerpc/include/asm/uaccess.h@@ -53,9 +53,6 @@ static inline bool __access_ok(unsigned long addr, unsigned long size) #define __put_user(x, ptr) \ __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) -#define __get_user_allowed(x, ptr) \ - __get_user_nocheck((x), (ptr), sizeof(*(ptr)), false) - #define __get_user_inatomic(x, ptr) \ __get_user_nosleep((x), (ptr), sizeof(*(ptr))) #define __put_user_inatomic(x, ptr) \@@ -482,8 +479,11 @@ user_write_access_begin(const void __user *ptr, size_t len) #define user_write_access_begin user_write_access_begin #define user_write_access_end prevent_current_write_to_user -#define unsafe_op_wrap(op, err) do { if (unlikely(op)) goto err; } while (0) -#define unsafe_get_user(x, p, e) unsafe_op_wrap(__get_user_allowed(x, p), e) +#define unsafe_get_user(x, p, e) do { \ + if (unlikely(__get_user_nocheck((x), (p), sizeof(*(p)), false)))\ + goto e; \ +} while (0) +
This seems correct to me.
Checkpatch does have one check that is relevant:
CHECK: Macro argument reuse 'p' - possible side-effects?
#36: FILE: arch/powerpc/include/asm/uaccess.h:482:
+#define unsafe_get_user(x, p, e) do { \
+ if (unlikely(__get_user_nocheck((x), (p), sizeof(*(p)), false)))\
+ goto e; \
+} while (0)
Given that we are already creating a new block, should we do something
like this (completely untested):
#define unsafe_get_user(x, p, e) do { \
__typeof__(p) __p = (p);
if (unlikely(__get_user_nocheck((x), (__p), sizeof(*(__p)), false)))\
goto e; \
} while (0)
Kind regards,
Daniel
#define unsafe_put_user(x, p, e) \ __unsafe_put_user_goto((__typeof__(*(p)))(x), (p), sizeof(*(p)), e) -- 2.25.0