Properly use masked_user_read_access_begin() and masked_user_write_access_begin() instead of masked_user_access_begin() in order to match user_read_access_end() and user_write_access_end(). This is important for architectures like powerpc that enable separately user reads and user writes.
That means masked_user_read_access_begin() is used when user memory is exclusively read during the window and masked_user_write_access_begin() is used when user memory is exclusively writen during the window. masked_user_access_begin() remains and is used when both reads and writes are performed during the open window. Each of them is expected to be terminated by the matching user_read_access_end(), user_write_access_end() and user_access_end(). Signed-off-by: Christophe Leroy <[email protected]> --- v4: Rebased on top of core-scoped-uaccess tag v3: Rebased on top of v6.18-rc1 ==> change in net/core/scm.c v2: Added more explanations in the commit message following comments received. --- lib/strncpy_from_user.c | 2 +- lib/strnlen_user.c | 2 +- net/core/scm.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/lib/strncpy_from_user.c b/lib/strncpy_from_user.c index 6dc234913dd58..5bb752ff7c61b 100644 --- a/lib/strncpy_from_user.c +++ b/lib/strncpy_from_user.c @@ -126,7 +126,7 @@ long strncpy_from_user(char *dst, const char __user *src, long count) if (can_do_masked_user_access()) { long retval; - src = masked_user_access_begin(src); + src = masked_user_read_access_begin(src); retval = do_strncpy_from_user(dst, src, count, count); user_read_access_end(); return retval; diff --git a/lib/strnlen_user.c b/lib/strnlen_user.c index 6e489f9e90f15..4a6574b67f824 100644 --- a/lib/strnlen_user.c +++ b/lib/strnlen_user.c @@ -99,7 +99,7 @@ long strnlen_user(const char __user *str, long count) if (can_do_masked_user_access()) { long retval; - str = masked_user_access_begin(str); + str = masked_user_read_access_begin(str); retval = do_strnlen_user(str, count, count); user_read_access_end(); return retval; diff --git a/net/core/scm.c b/net/core/scm.c index 66eaee783e8be..4a65f9baa87e7 100644 --- a/net/core/scm.c +++ b/net/core/scm.c @@ -274,7 +274,7 @@ int put_cmsg(struct msghdr * msg, int level, int type, int len, void *data) check_object_size(data, cmlen - sizeof(*cm), true); if (can_do_masked_user_access()) - cm = masked_user_access_begin(cm); + cm = masked_user_write_access_begin(cm); else if (!user_write_access_begin(cm, cmlen)) goto efault; -- 2.49.0
