summaryrefslogtreecommitdiff
path: root/arch/x86/entry
diff options
context:
space:
mode:
authorJosh Poimboeuf <jpoimboe@kernel.org>2022-06-15 00:16:05 +0300
committerBorislav Petkov <bp@suse.de>2022-06-27 11:34:00 +0300
commitb2620facef4889fefcbf2e87284f34dcd4189bce (patch)
tree52439ac589efbe3e3c881eba84cddb489e205c37 /arch/x86/entry
parentd7caac991feeef1b871ee6988fd2c9725df09039 (diff)
downloadlinux-b2620facef4889fefcbf2e87284f34dcd4189bce.tar.xz
x86/speculation: Fix RSB filling with CONFIG_RETPOLINE=n
If a kernel is built with CONFIG_RETPOLINE=n, but the user still wants to mitigate Spectre v2 using IBRS or eIBRS, the RSB filling will be silently disabled. There's nothing retpoline-specific about RSB buffer filling. Remove the CONFIG_RETPOLINE guards around it. Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de>
Diffstat (limited to 'arch/x86/entry')
-rw-r--r--arch/x86/entry/entry_32.S2
-rw-r--r--arch/x86/entry/entry_64.S2
2 files changed, 0 insertions, 4 deletions
diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index 887420844066..e309e7156038 100644
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -698,7 +698,6 @@ SYM_CODE_START(__switch_to_asm)
movl %ebx, PER_CPU_VAR(__stack_chk_guard)
#endif
-#ifdef CONFIG_RETPOLINE
/*
* When switching from a shallower to a deeper call stack
* the RSB may either underflow or use entries populated
@@ -707,7 +706,6 @@ SYM_CODE_START(__switch_to_asm)
* speculative execution to prevent attack.
*/
FILL_RETURN_BUFFER %ebx, RSB_CLEAR_LOOPS, X86_FEATURE_RSB_CTXSW
-#endif
/* Restore flags or the incoming task to restore AC state. */
popfl
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 65e3b8b7cbe5..a4ba162e52c3 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -255,7 +255,6 @@ SYM_FUNC_START(__switch_to_asm)
movq %rbx, PER_CPU_VAR(fixed_percpu_data) + stack_canary_offset
#endif
-#ifdef CONFIG_RETPOLINE
/*
* When switching from a shallower to a deeper call stack
* the RSB may either underflow or use entries populated
@@ -264,7 +263,6 @@ SYM_FUNC_START(__switch_to_asm)
* speculative execution to prevent attack.
*/
FILL_RETURN_BUFFER %r12, RSB_CLEAR_LOOPS, X86_FEATURE_RSB_CTXSW
-#endif
/* restore callee-saved registers */
popq %r15