linux/arch/x86
Peter Zijlstra 87c87ecd00 bpf,x86: Respect X86_FEATURE_RETPOLINE*
Current BPF codegen doesn't respect X86_FEATURE_RETPOLINE* flags and
unconditionally emits a thunk call, this is sub-optimal and doesn't
match the regular, compiler generated, code.

Update the i386 JIT to emit code equal to what the compiler emits for
the regular kernel text (IOW. a plain THUNK call).

Update the x86_64 JIT to emit code similar to the result of compiler
and kernel rewrites as according to X86_FEATURE_RETPOLINE* flags.
Inlining RETPOLINE_AMD (lfence; jmp *%reg) and !RETPOLINE (jmp *%reg),
while doing a THUNK call for RETPOLINE.

This removes the hard-coded retpoline thunks and shrinks the generated
code. Leaving a single retpoline thunk definition in the kernel.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20211026120310.614772675@infradead.org
2021-10-28 23:25:29 +02:00
..
boot Kbuild updates for v5.15 2021-09-03 15:33:47 -07:00
configs configs: remove the obsolete CONFIG_INPUT_POLLDEV 2021-09-08 11:50:28 -07:00
crypto crypto: x86/sm4 - Fix frame pointer stack corruption 2021-09-24 15:58:50 +08:00
entry compat: remove some compat entry points 2021-09-08 15:32:35 -07:00
events perf/x86/intel: Update event constraints for ICX 2021-10-01 13:57:54 +02:00
hyperv hyperv-fixes for 5.15-rc2 2021-09-15 17:18:56 -07:00
ia32 binfmt: remove in-tree usage of MAP_DENYWRITE 2021-09-03 18:42:01 +02:00
include bpf,x86: Respect X86_FEATURE_RETPOLINE* 2021-10-28 23:25:29 +02:00
kernel x86,bugs: Unconditionally allow spectre_v2=retpoline,amd 2021-10-28 23:25:29 +02:00
kvm Merge branch 'objtool/urgent' 2021-10-07 00:40:17 +02:00
lib x86/retpoline: Create a retpoline thunk array 2021-10-28 23:25:27 +02:00
math-emu x86/math-emu: Rename frstor() 2021-06-23 18:16:33 +02:00
mm x86/fault: Fix wrong signal when vsyscall fails with pkey 2021-09-20 22:28:47 +02:00
net bpf,x86: Respect X86_FEATURE_RETPOLINE* 2021-10-28 23:25:29 +02:00
pci pci-v5.15-changes 2021-09-07 19:13:42 -07:00
platform EFI changes: two driver API cleanups, and a log message tweak. 2021-06-28 11:34:16 -07:00
power x86/power: Fix kernel-doc warnings in cpu.c 2021-08-12 10:15:40 +02:00
purgatory kernel.h: split out panic and oops helpers 2021-07-01 11:06:04 -07:00
ras
realmode memblock: make memblock_find_in_range method private 2021-09-03 09:58:17 -07:00
tools - Remove cc-option checks which are old and already supported by the 2021-08-30 13:27:16 -07:00
um um: fix stub location calculation 2021-08-26 22:28:03 +02:00
video
xen Merge branch 'objtool/urgent' 2021-10-07 00:40:17 +02:00
.gitignore
Kbuild
Kconfig xen: branch for v5.15-rc3 2021-09-25 15:37:31 -07:00
Kconfig.assembler
Kconfig.cpu
Kconfig.debug tracing: Refactor TRACE_IRQFLAGS_SUPPORT in Kconfig 2021-08-16 11:37:21 -04:00
Makefile Kbuild updates for v5.15 2021-09-03 15:33:47 -07:00
Makefile_32.cpu x86/build: Do not add -falign flags unconditionally for clang 2021-09-19 10:35:53 +09:00
Makefile.um um: allow not setting extra rpaths in the linux binary 2021-06-17 21:54:15 +02:00