The following commit has been merged into the x86/bugs branch of tip:
Commit-ID: eeb9f34df065f42f0c9195b322ba6df420c9fc92
Gitweb: https://git.kernel.org/tip/eeb9f34df065f42f0c9195b322ba6df420c9fc92
Author: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
AuthorDate: Mon, 04 Sep 2023 22:04:53 -07:00
Committer: Borislav Petkov (AMD) <bp@xxxxxxxxx>
CommitterDate: Fri, 20 Oct 2023 11:46:59 +02:00
x86/srso: Fix unret validation dependencies
CONFIG_CPU_SRSO isn't dependent on CONFIG_CPU_UNRET_ENTRY (AMD
Retbleed), so the two features are independently configurable. Fix
several issues for the (presumably rare) case where CONFIG_CPU_SRSO is
enabled but CONFIG_CPU_UNRET_ENTRY isn't.
Fixes: fb3bd914b3ec ("x86/srso: Add a Speculative RAS Overflow mitigation")
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Acked-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Link: https://lore.kernel.org/r/299fb7740174d0f2335e91c58af0e9c242b4bac1.1693889988.git.jpoimboe@xxxxxxxxxx
---
arch/x86/include/asm/nospec-branch.h | 4 ++--
include/linux/objtool.h | 3 ++-
scripts/Makefile.vmlinux_o | 3 ++-
3 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h
index c55cc24..197ff4f 100644
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -271,7 +271,7 @@
.Lskip_rsb_\@:
.endm
-#ifdef CONFIG_CPU_UNRET_ENTRY
+#if defined(CONFIG_CPU_UNRET_ENTRY) || defined(CONFIG_CPU_SRSO)
#define CALL_UNTRAIN_RET "call entry_untrain_ret"
#else
#define CALL_UNTRAIN_RET ""
@@ -312,7 +312,7 @@
.macro UNTRAIN_RET_FROM_CALL
#if defined(CONFIG_CPU_UNRET_ENTRY) || defined(CONFIG_CPU_IBPB_ENTRY) || \
- defined(CONFIG_CALL_DEPTH_TRACKING)
+ defined(CONFIG_CALL_DEPTH_TRACKING) || defined(CONFIG_CPU_SRSO)
VALIDATE_UNRET_END
ALTERNATIVE_3 "", \
CALL_UNTRAIN_RET, X86_FEATURE_UNRET, \
diff --git a/include/linux/objtool.h b/include/linux/objtool.h
index 03f82c2..b5440e7 100644
--- a/include/linux/objtool.h
+++ b/include/linux/objtool.h
@@ -130,7 +130,8 @@
* it will be ignored.
*/
.macro VALIDATE_UNRET_BEGIN
-#if defined(CONFIG_NOINSTR_VALIDATION) && defined(CONFIG_CPU_UNRET_ENTRY)
+#if defined(CONFIG_NOINSTR_VALIDATION) && \
+ (defined(CONFIG_CPU_UNRET_ENTRY) || defined(CONFIG_CPU_SRSO))
.Lhere_\@:
.pushsection .discard.validate_unret
.long .Lhere_\@ - .
diff --git a/scripts/Makefile.vmlinux_o b/scripts/Makefile.vmlinux_o
index 0edfdb4..25b3b58 100644
--- a/scripts/Makefile.vmlinux_o
+++ b/scripts/Makefile.vmlinux_o
@@ -37,7 +37,8 @@ objtool-enabled := $(or $(delay-objtool),$(CONFIG_NOINSTR_VALIDATION))
vmlinux-objtool-args-$(delay-objtool) += $(objtool-args-y)
vmlinux-objtool-args-$(CONFIG_GCOV_KERNEL) += --no-unreachable
-vmlinux-objtool-args-$(CONFIG_NOINSTR_VALIDATION) += --noinstr $(if $(CONFIG_CPU_UNRET_ENTRY), --unret)
+vmlinux-objtool-args-$(CONFIG_NOINSTR_VALIDATION) += --noinstr \
+ $(if $(or $(CONFIG_CPU_UNRET_ENTRY),$(CONFIG_CPU_SRSO)), --unret)
objtool-args = $(vmlinux-objtool-args-y) --link
|