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authorAlejandro Colomar <alx.manpages@gmail.com>2020-11-28 13:39:46 +0100
committerThomas Gleixner <tglx@linutronix.de>2021-01-28 13:20:18 +0100
commit1ce53e2c2ac069e7b3c400a427002a70deb4a916 (patch)
treef980a8c689030b609996f9362a3f93ea54ccebe4 /kernel/futex.c
parent997acaf6b4b59c6a9c259740312a69ea549cc684 (diff)
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futex: Change utime parameter to be 'const ... *'
futex(2) says that 'utime' is a pointer to 'const'. The implementation doesn't use 'const'; however, it _never_ modifies the contents of utime. - futex() either uses 'utime' as a pointer to struct or as a 'u32'. - In case it's used as a 'u32', it makes a copy of it, and of course it is not dereferenced. - In case it's used as a 'struct __kernel_timespec __user *', the pointer is not dereferenced inside the futex() definition, and it is only passed to a function: get_timespec64(), which accepts a 'const struct __kernel_timespec __user *'. [ tglx: Make the same change to the compat syscall and fixup the prototypes. ] Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20201128123945.4592-1-alx.manpages@gmail.com
Diffstat (limited to 'kernel/futex.c')
-rw-r--r--kernel/futex.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/kernel/futex.c b/kernel/futex.c
index c47d1015d759..d0775aab8da9 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -3790,8 +3790,8 @@ long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val,
- struct __kernel_timespec __user *, utime, u32 __user *, uaddr2,
- u32, val3)
+ const struct __kernel_timespec __user *, utime,
+ u32 __user *, uaddr2, u32, val3)
{
struct timespec64 ts;
ktime_t t, *tp = NULL;
@@ -3986,7 +3986,7 @@ err_unlock:
#ifdef CONFIG_COMPAT_32BIT_TIME
SYSCALL_DEFINE6(futex_time32, u32 __user *, uaddr, int, op, u32, val,
- struct old_timespec32 __user *, utime, u32 __user *, uaddr2,
+ const struct old_timespec32 __user *, utime, u32 __user *, uaddr2,
u32, val3)
{
struct timespec64 ts;