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| author | Peter Collingbourne <pcc@google.com> | 2021-09-15 22:03:35 +0300 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2021-09-21 14:17:30 +0300 |
| commit | 8c8a3b5bd960cd88f7655b5251dc28741e11f139 (patch) | |
| tree | bc716ac5b48029dcdb82f57361d50b35e417ae4d /arch/arm64/include/asm/mte.h | |
| parent | 9fcb2e93f41c07a400885325e7dbdfceba6efaec (diff) | |
| download | linux-8c8a3b5bd960cd88f7655b5251dc28741e11f139.tar.xz | |
arm64: add MTE supported check to thread switching and syscall entry/exit
This lets us avoid doing unnecessary work on hardware that does not
support MTE, and will allow us to freely use MTE instructions in the
code called by mte_thread_switch().
Since this would mean that we do a redundant check in
mte_check_tfsr_el1(), remove it and add two checks now required in its
callers. This also avoids an unnecessary DSB+ISB sequence on the syscall
exit path for hardware not supporting MTE.
Fixes: 65812c6921cc ("arm64: mte: Enable async tag check fault")
Cc: <stable@vger.kernel.org> # 5.13.x
Signed-off-by: Peter Collingbourne <pcc@google.com>
Link: https://linux-review.googlesource.com/id/I02fd000d1ef2c86c7d2952a7f099b254ec227a5d
Link: https://lore.kernel.org/r/20210915190336.398390-1-pcc@google.com
[catalin.marinas@arm.com: adjust the commit log slightly]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/include/asm/mte.h')
| -rw-r--r-- | arch/arm64/include/asm/mte.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/mte.h b/arch/arm64/include/asm/mte.h index 3f93b9e0b339..02511650cffe 100644 --- a/arch/arm64/include/asm/mte.h +++ b/arch/arm64/include/asm/mte.h @@ -99,11 +99,17 @@ void mte_check_tfsr_el1(void); static inline void mte_check_tfsr_entry(void) { + if (!system_supports_mte()) + return; + mte_check_tfsr_el1(); } static inline void mte_check_tfsr_exit(void) { + if (!system_supports_mte()) + return; + /* * The asynchronous faults are sync'ed automatically with * TFSR_EL1 on kernel entry but for exit an explicit dsb() |