diff options
| author | Christoph Hellwig <hch@lst.de> | 2020-04-24 08:43:38 +0200 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2020-04-27 08:07:40 +0200 |
| commit | 32927393dc1ccd60fb2bdc05b9e8e88753761469 (patch) | |
| tree | c488a5564cdde7594c953219a98e22fb4865c812 /arch/s390/mm/cmm.c | |
| parent | sysctl: avoid forward declarations (diff) | |
| download | linux-32927393dc1ccd60fb2bdc05b9e8e88753761469.tar.xz linux-32927393dc1ccd60fb2bdc05b9e8e88753761469.zip | |
sysctl: pass kernel pointers to ->proc_handler
Instead of having all the sysctl handlers deal with user pointers, which
is rather hairy in terms of the BPF interaction, copy the input to and
from userspace in common code. This also means that the strings are
always NUL-terminated by the common code, making the API a little bit
safer.
As most handler just pass through the data to one of the common handlers
a lot of the changes are mechnical.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'arch/s390/mm/cmm.c')
| -rw-r--r-- | arch/s390/mm/cmm.c | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/arch/s390/mm/cmm.c b/arch/s390/mm/cmm.c index ae989b740376..36bce727897b 100644 --- a/arch/s390/mm/cmm.c +++ b/arch/s390/mm/cmm.c @@ -245,7 +245,7 @@ static int cmm_skip_blanks(char *cp, char **endp) } static int cmm_pages_handler(struct ctl_table *ctl, int write, - void __user *buffer, size_t *lenp, loff_t *ppos) + void *buffer, size_t *lenp, loff_t *ppos) { long nr = cmm_get_pages(); struct ctl_table ctl_entry = { @@ -264,7 +264,7 @@ static int cmm_pages_handler(struct ctl_table *ctl, int write, } static int cmm_timed_pages_handler(struct ctl_table *ctl, int write, - void __user *buffer, size_t *lenp, + void *buffer, size_t *lenp, loff_t *ppos) { long nr = cmm_get_timed_pages(); @@ -284,7 +284,7 @@ static int cmm_timed_pages_handler(struct ctl_table *ctl, int write, } static int cmm_timeout_handler(struct ctl_table *ctl, int write, - void __user *buffer, size_t *lenp, loff_t *ppos) + void *buffer, size_t *lenp, loff_t *ppos) { char buf[64], *p; long nr, seconds; @@ -297,8 +297,7 @@ static int cmm_timeout_handler(struct ctl_table *ctl, int write, if (write) { len = min(*lenp, sizeof(buf)); - if (copy_from_user(buf, buffer, len)) - return -EFAULT; + memcpy(buf, buffer, len); buf[len - 1] = '\0'; cmm_skip_blanks(buf, &p); nr = simple_strtoul(p, &p, 0); @@ -311,8 +310,7 @@ static int cmm_timeout_handler(struct ctl_table *ctl, int write, cmm_timeout_pages, cmm_timeout_seconds); if (len > *lenp) len = *lenp; - if (copy_to_user(buffer, buf, len)) - return -EFAULT; + memcpy(buffer, buf, len); *lenp = len; *ppos += len; } |