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authorJakub Kicinski <kuba@kernel.org>2022-07-14 14:19:42 -0700
committerJakub Kicinski <kuba@kernel.org>2022-07-14 15:27:35 -0700
commit816cd1688331e0ffa1927889c15e7ed56650a183 (patch)
tree30cbcb7d5d4e1dd226fda651f25ca094e54714a0 /arch/x86/entry/calling.h
parentb126047f43f11f61f1dd64802979765d71795dae (diff)
parentdb886979683a8360ced9b24ab1125ad0c4d2cf76 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
include/net/sock.h 310731e2f161 ("net: Fix data-races around sysctl_mem.") e70f3c701276 ("Revert "net: set SK_MEM_QUANTUM to 4096"") https://lore.kernel.org/all/20220711120211.7c8b7cba@canb.auug.org.au/ net/ipv4/fib_semantics.c 747c14307214 ("ip: fix dflt addr selection for connected nexthop") d62607c3fe45 ("net: rename reference+tracking helpers") net/tls/tls.h include/net/tls.h 3d8c51b25a23 ("net/tls: Check for errors in tls_device_init") 587903142308 ("tls: create an internal header") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'arch/x86/entry/calling.h')
-rw-r--r--arch/x86/entry/calling.h62
1 files changed, 62 insertions, 0 deletions
diff --git a/arch/x86/entry/calling.h b/arch/x86/entry/calling.h
index 29b36e9e4e74..f6907627172b 100644
--- a/arch/x86/entry/calling.h
+++ b/arch/x86/entry/calling.h
@@ -7,6 +7,8 @@
#include <asm/asm-offsets.h>
#include <asm/processor-flags.h>
#include <asm/ptrace-abi.h>
+#include <asm/msr.h>
+#include <asm/nospec-branch.h>
/*
@@ -283,6 +285,66 @@ For 32-bit we have the following conventions - kernel is built with
#endif
/*
+ * IBRS kernel mitigation for Spectre_v2.
+ *
+ * Assumes full context is established (PUSH_REGS, CR3 and GS) and it clobbers
+ * the regs it uses (AX, CX, DX). Must be called before the first RET
+ * instruction (NOTE! UNTRAIN_RET includes a RET instruction)
+ *
+ * The optional argument is used to save/restore the current value,
+ * which is used on the paranoid paths.
+ *
+ * Assumes x86_spec_ctrl_{base,current} to have SPEC_CTRL_IBRS set.
+ */
+.macro IBRS_ENTER save_reg
+#ifdef CONFIG_CPU_IBRS_ENTRY
+ ALTERNATIVE "jmp .Lend_\@", "", X86_FEATURE_KERNEL_IBRS
+ movl $MSR_IA32_SPEC_CTRL, %ecx
+
+.ifnb \save_reg
+ rdmsr
+ shl $32, %rdx
+ or %rdx, %rax
+ mov %rax, \save_reg
+ test $SPEC_CTRL_IBRS, %eax
+ jz .Ldo_wrmsr_\@
+ lfence
+ jmp .Lend_\@
+.Ldo_wrmsr_\@:
+.endif
+
+ movq PER_CPU_VAR(x86_spec_ctrl_current), %rdx
+ movl %edx, %eax
+ shr $32, %rdx
+ wrmsr
+.Lend_\@:
+#endif
+.endm
+
+/*
+ * Similar to IBRS_ENTER, requires KERNEL GS,CR3 and clobbers (AX, CX, DX)
+ * regs. Must be called after the last RET.
+ */
+.macro IBRS_EXIT save_reg
+#ifdef CONFIG_CPU_IBRS_ENTRY
+ ALTERNATIVE "jmp .Lend_\@", "", X86_FEATURE_KERNEL_IBRS
+ movl $MSR_IA32_SPEC_CTRL, %ecx
+
+.ifnb \save_reg
+ mov \save_reg, %rdx
+.else
+ movq PER_CPU_VAR(x86_spec_ctrl_current), %rdx
+ andl $(~SPEC_CTRL_IBRS), %edx
+.endif
+
+ movl %edx, %eax
+ shr $32, %rdx
+ wrmsr
+.Lend_\@:
+#endif
+.endm
+
+/*
* Mitigate Spectre v1 for conditional swapgs code paths.
*
* FENCE_SWAPGS_USER_ENTRY is used in the user entry swapgs code path, to