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(parent: d191323) | patch
xtensa: don't use a12 in __xtensa_copy_user in call0 ABI
authorMax Filippov <jcmvbkbc@gmail.com>
Sun, 25 Jul 2021 23:31:34 +0000 (16:31 -0700)
committerMax Filippov <jcmvbkbc@gmail.com>
Tue, 19 Oct 2021 05:19:34 +0000 (22:19 -0700)
commit61a6b91283b4c9e308fcf9377d3f0598ceccb252
tree8d96ceb3f4f4bbd4bf6deff7822814008e9459d0tree | snapshot
parentd191323bc02370667fede74228135440efd98d2bcommit | diff
xtensa: don't use a12 in __xtensa_copy_user in call0 ABI

a12 is callee-saved register in xtensa call0 ABI, so a function must not
change it. The main unaligned copy loop of __xtensa_copy_user uses all
low-numbered registers, so a register must be spilled to avoid using a12
as a loop counter.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
arch/xtensa/lib/usercopy.S diff | blob | history
Domain: System / Kernel;