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authorJakub Kicinski <kuba@kernel.org>2025-07-10 10:08:47 -0700
committerJakub Kicinski <kuba@kernel.org>2025-07-10 10:10:49 -0700
commit3321e97eab71df7d632b35276da9f8503e6e040f (patch)
tree6a4ec5e7556d99a0ff25f4035f078d8e0186f359 /arch/x86/include/asm/nospec-branch.h
parente090f978054e1cfcd970234589168fcbcba33976 (diff)
parentbc9ff192a6c940d9a26e21a0a82f2667067aaf5f (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-6.16-rc6). No conflicts. Adjacent changes: Documentation/devicetree/bindings/net/allwinner,sun8i-a83t-emac.yaml 0a12c435a1d6 ("dt-bindings: net: sun8i-emac: Add A100 EMAC compatible") b3603c0466a8 ("dt-bindings: net: sun8i-emac: Rename A523 EMAC0 to GMAC0") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'arch/x86/include/asm/nospec-branch.h')
-rw-r--r--arch/x86/include/asm/nospec-branch.h37
1 files changed, 22 insertions, 15 deletions
diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h
index 20d754b98f3f..10f261678749 100644
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -302,25 +302,31 @@
.endm
/*
- * Macro to execute VERW instruction that mitigate transient data sampling
- * attacks such as MDS. On affected systems a microcode update overloaded VERW
- * instruction to also clear the CPU buffers. VERW clobbers CFLAGS.ZF.
- *
+ * Macro to execute VERW insns that mitigate transient data sampling
+ * attacks such as MDS or TSA. On affected systems a microcode update
+ * overloaded VERW insns to also clear the CPU buffers. VERW clobbers
+ * CFLAGS.ZF.
* Note: Only the memory operand variant of VERW clears the CPU buffers.
*/
-.macro CLEAR_CPU_BUFFERS
+.macro __CLEAR_CPU_BUFFERS feature
#ifdef CONFIG_X86_64
- ALTERNATIVE "", "verw mds_verw_sel(%rip)", X86_FEATURE_CLEAR_CPU_BUF
+ ALTERNATIVE "", "verw x86_verw_sel(%rip)", \feature
#else
/*
* In 32bit mode, the memory operand must be a %cs reference. The data
* segments may not be usable (vm86 mode), and the stack segment may not
* be flat (ESPFIX32).
*/
- ALTERNATIVE "", "verw %cs:mds_verw_sel", X86_FEATURE_CLEAR_CPU_BUF
+ ALTERNATIVE "", "verw %cs:x86_verw_sel", \feature
#endif
.endm
+#define CLEAR_CPU_BUFFERS \
+ __CLEAR_CPU_BUFFERS X86_FEATURE_CLEAR_CPU_BUF
+
+#define VM_CLEAR_CPU_BUFFERS \
+ __CLEAR_CPU_BUFFERS X86_FEATURE_CLEAR_CPU_BUF_VM
+
#ifdef CONFIG_X86_64
.macro CLEAR_BRANCH_HISTORY
ALTERNATIVE "", "call clear_bhb_loop", X86_FEATURE_CLEAR_BHB_LOOP
@@ -567,24 +573,24 @@ DECLARE_STATIC_KEY_FALSE(switch_mm_always_ibpb);
DECLARE_STATIC_KEY_FALSE(switch_vcpu_ibpb);
-DECLARE_STATIC_KEY_FALSE(mds_idle_clear);
+DECLARE_STATIC_KEY_FALSE(cpu_buf_idle_clear);
DECLARE_STATIC_KEY_FALSE(switch_mm_cond_l1d_flush);
DECLARE_STATIC_KEY_FALSE(cpu_buf_vm_clear);
-extern u16 mds_verw_sel;
+extern u16 x86_verw_sel;
#include <asm/segment.h>
/**
- * mds_clear_cpu_buffers - Mitigation for MDS and TAA vulnerability
+ * x86_clear_cpu_buffers - Buffer clearing support for different x86 CPU vulns
*
* This uses the otherwise unused and obsolete VERW instruction in
* combination with microcode which triggers a CPU buffer flush when the
* instruction is executed.
*/
-static __always_inline void mds_clear_cpu_buffers(void)
+static __always_inline void x86_clear_cpu_buffers(void)
{
static const u16 ds = __KERNEL_DS;
@@ -601,14 +607,15 @@ static __always_inline void mds_clear_cpu_buffers(void)
}
/**
- * mds_idle_clear_cpu_buffers - Mitigation for MDS vulnerability
+ * x86_idle_clear_cpu_buffers - Buffer clearing support in idle for the MDS
+ * and TSA vulnerabilities.
*
* Clear CPU buffers if the corresponding static key is enabled
*/
-static __always_inline void mds_idle_clear_cpu_buffers(void)
+static __always_inline void x86_idle_clear_cpu_buffers(void)
{
- if (static_branch_likely(&mds_idle_clear))
- mds_clear_cpu_buffers();
+ if (static_branch_likely(&cpu_buf_idle_clear))
+ x86_clear_cpu_buffers();
}
#endif /* __ASSEMBLER__ */