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Yosry Ahmed 8f64eee70c x86/bugs: Remove X86_FEATURE_USE_IBPB 
X86_FEATURE_USE_IBPB was introduced in:

  2961298efe ("x86/cpufeatures: Clean up Spectre v2 related CPUID flags")

to have separate flags for when the CPU supports IBPB (i.e. X86_FEATURE_IBPB)
and when an IBPB is actually used to mitigate Spectre v2.

Ever since then, the uses of IBPB expanded. The name became confusing
because it does not control all IBPB executions in the kernel.
Furthermore, because its name is generic and it's buried within
indirect_branch_prediction_barrier(), it's easy to use it not knowing
that it is specific to Spectre v2.

X86_FEATURE_USE_IBPB is no longer needed because all the IBPB executions
it used to control are now controlled through other means (e.g.
switch_mm_*_ibpb static branches).

Remove the unused feature bit.

Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/20250227012712.3193063-7-yosry.ahmed@linux.dev
History 2025-02-27 10:57:21 +01:00
..
alpha/include tools headers uapi: Sync asm-generic/mman-common.h and linux/mman.h 2019-03-28 14:31:56 -03:00
arc/include/uapi/asm tools arch uapi: Copy missing unistd.h headers for arc, hexagon and riscv 2019-05-02 16:00:20 -04:00
arm/include tools headers kvm: Sync kvm headers with the kernel sources 2019-12-02 12:54:13 -03:00
arm64 arm64/sysreg/tools: Move TRFCR definitions to sysreg 2025-01-12 12:50:11 +00:00
csky/include/uapi/asm csky: Add support for libdw 2019-05-15 16:36:46 -03:00
hexagon/include/uapi/asm tools arch: Remove uapi bitsperlong.h of hexagon and microblaze 2023-06-22 17:04:37 +02:00
loongarch/include selftests: vDSO: unconditionally build chacha test 2024-10-08 15:21:29 -06:00
microblaze/include/uapi/asm tools arch: Remove uapi bitsperlong.h of hexagon and microblaze 2023-06-22 17:04:37 +02:00
mips/include perf tools: Copy uapi/asm/perf_regs.h from the kernel for MIPS 2021-06-01 10:07:46 -03:00
parisc/include/uapi/asm parisc: Drop the HP-UX ENOSYM and EREMOTERELEASE error codes 2023-11-25 09:43:18 +01:00
powerpc/include selftests: vDSO: unconditionally build chacha test 2024-10-08 15:21:29 -06:00
riscv/include tools: Add riscv barrier implementation 2024-09-20 01:46:46 -07:00
s390/include - second part of the ucontrol selftest 2024-11-12 13:17:55 -05:00
sh/include sh: remove sh5 support 2020-06-01 14:48:52 -04:00
sparc/include tools headers UAPI: Update tools's copy of mman.h headers 2019-07-29 09:02:58 -03:00
x86 x86/bugs: Remove X86_FEATURE_USE_IBPB 2025-02-27 10:57:21 +01:00
xtensa/include tools headers uapi: Sync asm-generic/mman-common.h and linux/mman.h 2019-03-28 14:31:56 -03:00