TechPanelGM/kernel_xiaomi_sm8250
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

arm64: Add support for SB barrier and patch in over DSB; ISB sequences

Browse Source 
[ Upstream commit bd4fb6d270bc423a9a4098108784f7f9254c4e6d ]

We currently use a DSB; ISB sequence to inhibit speculation in set_fs().
Whilst this works for current CPUs, future CPUs may implement a new SB
barrier instruction which acts as an architected speculation barrier.

On CPUs that support it, patch in an SB; NOP sequence over the DSB; ISB
sequence and advertise the presence of the new instruction to userspace.

Signed-off-by: Will Deacon <will.deacon@arm.com>
[ Mark: fixup conflicts ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Will Deacon
2024-08-09 11:43:43 +01:00
committed by Greg Kroah-Hartman
parent 585b8d86c3
commit ced08f48bd
8 changed files with 40 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
arch/arm64/include/uapi/asm/hwcap.h
View File

@@ -49,5 +49,6 @@
#define HWCAP_ILRCPC (1 << 26)
#define HWCAP_FLAGM (1 << 27)
#define HWCAP_SSBS (1 << 28)
#define HWCAP_SB (1 << 29)
#endif /* _UAPI__ASM_HWCAP_H */