wireguard-linux/arch/xtensa/include/asm/uaccess.h, branch jd/orphan-parallel

uaccess: remove segment_eq

2020-08-12T17:57:58Z

segment_eq is only used to implement uaccess_kernel. Just open code uaccess_kernel in the arch uaccess headers and remove one layer of indirection. Signed-off-by: Christoph Hellwig Signed-off-by: Andrew Morton Acked-by: Linus Torvalds Acked-by: Greentime Hu Acked-by: Geert Uytterhoeven Cc: Nick Hu Cc: Vincent Chen Cc: Paul Walmsley Cc: Palmer Dabbelt Link: http://lkml.kernel.org/r/20200710135706.537715-5-hch@lst.de Signed-off-by: Linus Torvalds

xtensa: add missing __user annotations to asm/uaccess.h

2020-05-22T23:09:00Z

clear_user, strncpy_user, strnlen_user and their helpers operate on user pointers, but don't have their arguments marked as __user. Add __user annotation to userspace pointers of those functions. Fix open-coded access check in the strnlen_user while at it. Signed-off-by: Max Filippov

xtensa: fix error paths in __get_user_{check,size}

2020-05-22T23:09:00Z

Error paths in __get_user_check and __get_user_size directly assing 0 to the result. It causes the following sparse warnings: sparse: warning: Using plain integer as NULL pointer Convert 0 to the type pointed to by the user pointer before assigning it. Signed-off-by: Max Filippov

xtensa: fix type conversion in __get_user_size

2020-05-22T21:33:52Z

8-byte access in __get_user_size converts pointer to temporary variable to the type of original user pointer and then dereferences it, resulting in the following sparse warning: sparse: warning: dereference of noderef expression Instead dereference the original user pointer under the __typeof__ and add indirection outside. Signed-off-by: Max Filippov

xtensa: add missing user annotations to {get,put}_user_check

2020-05-22T21:32:13Z

__get_user_check and __put_user_check use temporary pointer but don't mark it as __user, resulting in sparse warnings: sparse: warning: incorrect type in initializer (different address spaces) sparse: expected long *__pu_addr sparse: got long [noderef] *ret sparse: warning: incorrect type in argument 1 (different address spaces) sparse: expected void [noderef] *to sparse: got long *__pu_addr Add __user annotation to temporary pointer in __get_user_check and __put_user_check. Reported-by: kbuild test robot Reported-by: Arnd Bergmann Signed-off-by: Max Filippov

xtensa: use "m" constraint instead of "a" in uaccess.h assembly

2019-11-26T19:33:38Z

Use "m" constraint instead of "r" for the address, as "m" allows compiler to access adjacent locations using base + offset, while "r" requires updating the base register every time. Use %[mem] * 0 + v to replace offset part of %[mem] expansion with v. It is impossible to change address alignment through the offset part on xtensa, so just ignore offset in alignment checks. Signed-off-by: Max Filippov

xtensa: fix type conversion in __get_user_[no]check

2019-10-14T21:14:21Z

__get_user_[no]check uses temporary buffer of type long to store result of __get_user_size and do sign extension on it when necessary. This doesn't work correctly for 64-bit data. Fix it by moving temporary buffer/sign extension logic to __get_user_asm. Don't do assignment of __get_user_bad result to (x) as it may not always be integer-compatible now and issue warning even when it's going to be optimized. Instead do (x) = 0; and call __get_user_bad separately. Zero initialize __x in __get_user_asm and use '+' constraint for its assembly argument, so that its value is preserved in error cases. This may add at most 1 cycle to the fast path, but saves an instruction and two padding bytes in the fixup section for each use of this macro and works for both misaligned store and store exception. Signed-off-by: Max Filippov

xtensa: clean up assembly arguments in uaccess macros

2019-10-14T19:58:06Z

Numeric assembly arguments are hard to understand and assembly code that uses them is hard to modify. Use named arguments in __check_align_*, __get_user_asm and __put_user_asm. Modify macro parameter names so that they don't affect argument names. Use '+' constraint for the [err] argument instead of having it as both input and output. Signed-off-by: Max Filippov

xtensa: fix {get,put}_user() for 64bit values

2019-10-14T18:39:50Z

First of all, on short copies __copy_{to,from}_user() return the amount of bytes left uncopied, *not* -EFAULT. get_user() and put_user() are expected to return -EFAULT on failure. Another problem is get_user(v32, (__u64 __user *)p); that should fetch 64bit value and the assign it to v32, truncating it in process. Current code, OTOH, reads 8 bytes of data and stores them at the address of v32, stomping on the 4 bytes that follow v32 itself. Signed-off-by: Al Viro Signed-off-by: Max Filippov

get rid of legacy 'get_ds()' function

2019-03-04T18:50:14Z

Every in-kernel use of this function defined it to KERNEL_DS (either as an actual define, or as an inline function). It's an entirely historical artifact, and long long long ago used to actually read the segment selector valueof '%ds' on x86. Which in the kernel is always KERNEL_DS. Inspired by a patch from Jann Horn that just did this for a very small subset of users (the ones in fs/), along with Al who suggested a script. I then just took it to the logical extreme and removed all the remaining gunk. Roughly scripted with git grep -l '(get_ds())' -- :^tools/ | xargs sed -i 's/(get_ds())/(KERNEL_DS)/' git grep -lw 'get_ds' -- :^tools/ | xargs sed -i '/^#define get_ds()/d' plus manual fixups to remove a few unusual usage patterns, the couple of inline function cases and to fix up a comment that had become stale. The 'get_ds()' function remains in an x86 kvm selftest, since in user space it actually does something relevant. Inspired-by: Jann Horn Inspired-by: Al Viro Signed-off-by: Linus Torvalds