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| author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2021-03-19 11:06:50 +0000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-04-03 21:22:18 +1100 |
| commit | fb05121fd6a20f0830ff2a4420c51af6ca4ac6e7 (patch) | |
| tree | 60661671efe604c38eef1f701e04aeb6b4236c7e /include/linux/compat.h | |
| parent | 5cd29b1fd3e8f2b45fe6d011588d832417defe31 (diff) | |
| download | linux-fb05121fd6a20f0830ff2a4420c51af6ca4ac6e7.tar.gz linux-fb05121fd6a20f0830ff2a4420c51af6ca4ac6e7.tar.bz2 linux-fb05121fd6a20f0830ff2a4420c51af6ca4ac6e7.zip | |
signal: Add unsafe_get_compat_sigset()
In the same way as commit 14026b94ccfe ("signal: Add
unsafe_put_compat_sigset()"), this time add
unsafe_get_compat_sigset() macro which is the 'unsafe'
version of get_compat_sigset()
For the bigendian, use unsafe_get_user() directly
to avoid intermediate copy through the stack.
For the littleendian, use a straight unsafe_copy_from_user().
This commit adds the generic fallback for unsafe_copy_from_user().
Architectures wanting to use unsafe_get_compat_sigset() have to
make sure they have their own unsafe_copy_from_user().
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b05bf434ee13c76bc9df5f02653a10db5e7b54e5.1616151715.git.christophe.leroy@csgroup.eu
Diffstat (limited to 'include/linux/compat.h')
| -rw-r--r-- | include/linux/compat.h | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/include/linux/compat.h b/include/linux/compat.h index 6e65be753603..5112c3e35782 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -465,6 +465,34 @@ put_compat_sigset(compat_sigset_t __user *compat, const sigset_t *set, unsafe_put_user(__s->sig[0], &__c->sig[0], label); \ } \ } while (0) + +#define unsafe_get_compat_sigset(set, compat, label) do { \ + const compat_sigset_t __user *__c = compat; \ + compat_sigset_word hi, lo; \ + sigset_t *__s = set; \ + \ + switch (_NSIG_WORDS) { \ + case 4: \ + unsafe_get_user(lo, &__c->sig[7], label); \ + unsafe_get_user(hi, &__c->sig[6], label); \ + __s->sig[3] = hi | (((long)lo) << 32); \ + fallthrough; \ + case 3: \ + unsafe_get_user(lo, &__c->sig[5], label); \ + unsafe_get_user(hi, &__c->sig[4], label); \ + __s->sig[2] = hi | (((long)lo) << 32); \ + fallthrough; \ + case 2: \ + unsafe_get_user(lo, &__c->sig[3], label); \ + unsafe_get_user(hi, &__c->sig[2], label); \ + __s->sig[1] = hi | (((long)lo) << 32); \ + fallthrough; \ + case 1: \ + unsafe_get_user(lo, &__c->sig[1], label); \ + unsafe_get_user(hi, &__c->sig[0], label); \ + __s->sig[0] = hi | (((long)lo) << 32); \ + } \ +} while (0) #else #define unsafe_put_compat_sigset(compat, set, label) do { \ compat_sigset_t __user *__c = compat; \ @@ -472,6 +500,13 @@ put_compat_sigset(compat_sigset_t __user *compat, const sigset_t *set, \ unsafe_copy_to_user(__c, __s, sizeof(*__c), label); \ } while (0) + +#define unsafe_get_compat_sigset(set, compat, label) do { \ + const compat_sigset_t __user *__c = compat; \ + sigset_t *__s = set; \ + \ + unsafe_copy_from_user(__s, __c, sizeof(*__c), label); \ +} while (0) #endif extern int compat_ptrace_request(struct task_struct *child, |