signal: Add unsafe_get_compat_sigset()

In the same way as commit 14026b94cc ("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
This commit is contained in:
Christophe Leroy
2021-03-19 11:06:50 +00:00
committed by Michael Ellerman
parent 5cd29b1fd3
commit fb05121fd6
2 changed files with 36 additions and 0 deletions

View File

@@ -397,6 +397,7 @@ long strnlen_user_nofault(const void __user *unsafe_addr, long count);
#define unsafe_get_user(x,p,e) unsafe_op_wrap(__get_user(x,p),e)
#define unsafe_put_user(x,p,e) unsafe_op_wrap(__put_user(x,p),e)
#define unsafe_copy_to_user(d,s,l,e) unsafe_op_wrap(__copy_to_user(d,s,l),e)
#define unsafe_copy_from_user(d,s,l,e) unsafe_op_wrap(__copy_from_user(d,s,l),e)
static inline unsigned long user_access_save(void) { return 0UL; }
static inline void user_access_restore(unsigned long flags) { }
#endif