Linus Torvalds 1dbc0a9515 x86: mm: remove 'sign' games from LAM untagged_addr*() macros ... The intent of the sign games was to not modify kernel addresses when untagging them. However, that had two issues: (a) it didn't actually work as intended, since the mask was calculated as 'addr >> 63' on an _unsigned_ address. So instead of getting a mask of all ones for kernel addresses, you just got '1'. (b) untagging a kernel address isn't actually a valid operation anyway. Now, (a) had originally been true for both 'untagged_addr()' and the remote version of it, but had accidentally been fixed for the regular version of untagged_addr() by commit e0bddc19ba ("x86/mm: Reduce untagged_addr() overhead for systems without LAM"). That one rewrote the shift to be part of the alternative asm code, and in the process changed the unsigned shift into a signed 'sar' instruction. And while it is true that we don't want to turn what looks like a kernel address into a user address by masking off the high bit, that doesn't need these sign masking games - all it needs is that the mm context 'untag_mask' value has the high bit set. Which it always does. So simplify the code by just removing the superfluous (and in the case of untagged_addr_remote(), still buggy) sign bit games in the address masking. Acked-by: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2023-05-03 10:37:22 -07:00
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asm	x86: mm: remove 'sign' games from LAM untagged_addr*() macros	2023-05-03 10:37:22 -07:00
uapi/asm	s390:	2023-05-01 12:06:20 -07:00