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authorLinus Torvalds <torvalds@linux-foundation.org>2022-01-12 16:31:19 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2022-01-12 16:31:19 -0800
commit64ad9461521b1a357846ef6cedc4bccd48a046e0 (patch)
treef134404b6c6df89198a4a2f2be6fef21af133c73 /arch/x86/kernel/static_call.c
parent8e5b0adeea19309c8ce0e3c9119061554973efa9 (diff)
parent9cdbeec4096804083944d05da96bbaf59a1eb4f9 (diff)
Merge tag 'x86_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 core updates from Borislav Petkov: - Get rid of all the .fixup sections because this generates misleading/wrong stacktraces and confuse RELIABLE_STACKTRACE and LIVEPATCH as the backtrace misses the function which is being fixed up. - Add Straight Line Speculation mitigation support which uses a new compiler switch -mharden-sls= which sticks an INT3 after a RET or an indirect branch in order to block speculation after them. Reportedly, CPUs do speculate behind such insns. - The usual set of cleanups and improvements * tag 'x86_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits) x86/entry_32: Fix segment exceptions objtool: Remove .fixup handling x86: Remove .fixup section x86/word-at-a-time: Remove .fixup usage x86/usercopy: Remove .fixup usage x86/usercopy_32: Simplify __copy_user_intel_nocache() x86/sgx: Remove .fixup usage x86/checksum_32: Remove .fixup usage x86/vmx: Remove .fixup usage x86/kvm: Remove .fixup usage x86/segment: Remove .fixup usage x86/fpu: Remove .fixup usage x86/xen: Remove .fixup usage x86/uaccess: Remove .fixup usage x86/futex: Remove .fixup usage x86/msr: Remove .fixup usage x86/extable: Extend extable functionality x86/entry_32: Remove .fixup usage x86/entry_64: Remove .fixup usage x86/copy_mc_64: Remove .fixup usage ...
Diffstat (limited to 'arch/x86/kernel/static_call.c')
-rw-r--r--arch/x86/kernel/static_call.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/x86/kernel/static_call.c b/arch/x86/kernel/static_call.c
index 9c407a33a774..531fb4cbb63f 100644
--- a/arch/x86/kernel/static_call.c
+++ b/arch/x86/kernel/static_call.c
@@ -17,6 +17,8 @@ enum insn_type {
*/
static const u8 xor5rax[] = { 0x66, 0x66, 0x48, 0x31, 0xc0 };
+static const u8 retinsn[] = { RET_INSN_OPCODE, 0xcc, 0xcc, 0xcc, 0xcc };
+
static void __ref __static_call_transform(void *insn, enum insn_type type, void *func)
{
const void *emulate = NULL;
@@ -42,8 +44,7 @@ static void __ref __static_call_transform(void *insn, enum insn_type type, void
break;
case RET:
- code = text_gen_insn(RET_INSN_OPCODE, insn, func);
- size = RET_INSN_SIZE;
+ code = &retinsn;
break;
}