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
  ...

1 files changed, 47 insertions, 24 deletions

diff --git a/arch/x86/lib/insn-eval.c b/arch/x86/lib/insn-eval.c
index 53e57ef5925c..b781d324211b 100644
--- a/arch/x86/lib/insn-eval.c
+++ b/arch/x86/lib/insn-eval.c
@@ -410,32 +410,44 @@ static short get_segment_selector(struct pt_regs *regs, int seg_reg_idx)
 #endif /* CONFIG_X86_64 */
 }
 
-static int get_reg_offset(struct insn *insn, struct pt_regs *regs,
-			  enum reg_type type)
+static const int pt_regoff[] = {
+	offsetof(struct pt_regs, ax),
+	offsetof(struct pt_regs, cx),
+	offsetof(struct pt_regs, dx),
+	offsetof(struct pt_regs, bx),
+	offsetof(struct pt_regs, sp),
+	offsetof(struct pt_regs, bp),
+	offsetof(struct pt_regs, si),
+	offsetof(struct pt_regs, di),
+#ifdef CONFIG_X86_64
+	offsetof(struct pt_regs, r8),
+	offsetof(struct pt_regs, r9),
+	offsetof(struct pt_regs, r10),
+	offsetof(struct pt_regs, r11),
+	offsetof(struct pt_regs, r12),
+	offsetof(struct pt_regs, r13),
+	offsetof(struct pt_regs, r14),
+	offsetof(struct pt_regs, r15),
+#else
+	offsetof(struct pt_regs, ds),
+	offsetof(struct pt_regs, es),
+	offsetof(struct pt_regs, fs),
+	offsetof(struct pt_regs, gs),
+#endif
+};
+
+int pt_regs_offset(struct pt_regs *regs, int regno)
+{
+	if ((unsigned)regno < ARRAY_SIZE(pt_regoff))
+		return pt_regoff[regno];
+	return -EDOM;
+}
+
+static int get_regno(struct insn *insn, enum reg_type type)
 {
+	int nr_registers = ARRAY_SIZE(pt_regoff);
 	int regno = 0;
 
-	static const int regoff[] = {
-		offsetof(struct pt_regs, ax),
-		offsetof(struct pt_regs, cx),
-		offsetof(struct pt_regs, dx),
-		offsetof(struct pt_regs, bx),
-		offsetof(struct pt_regs, sp),
-		offsetof(struct pt_regs, bp),
-		offsetof(struct pt_regs, si),
-		offsetof(struct pt_regs, di),
-#ifdef CONFIG_X86_64
-		offsetof(struct pt_regs, r8),
-		offsetof(struct pt_regs, r9),
-		offsetof(struct pt_regs, r10),
-		offsetof(struct pt_regs, r11),
-		offsetof(struct pt_regs, r12),
-		offsetof(struct pt_regs, r13),
-		offsetof(struct pt_regs, r14),
-		offsetof(struct pt_regs, r15),
-#endif
-	};
-	int nr_registers = ARRAY_SIZE(regoff);
 	/*
 	 * Don't possibly decode a 32-bit instructions as
 	 * reading a 64-bit-only register.
@@ -503,7 +515,18 @@ static int get_reg_offset(struct insn *insn, struct pt_regs *regs,
 		WARN_ONCE(1, "decoded an instruction with an invalid register");
 		return -EINVAL;
 	}
-	return regoff[regno];
+	return regno;
+}
+
+static int get_reg_offset(struct insn *insn, struct pt_regs *regs,
+			  enum reg_type type)
+{
+	int regno = get_regno(insn, type);
+
+	if (regno < 0)
+		return regno;
+
+	return pt_regs_offset(regs, regno);
 }
 
 /**