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authorLinus Torvalds <torvalds@linux-foundation.org>2021-04-27 17:45:09 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-04-27 17:45:09 -0700
commitc6536676c7fe3f572ba55842e59c3c71c01e7fb3 (patch)
tree47482eee74657c959161bf10efcaad1c8b53ebd3 /tools/arch/x86/include/asm/nops.h
parente7c6e405e171fb33990a12ecfd14e6500d9e5cf2 (diff)
parent2c88d45edbb89029c1190bb3b136d2602f057c98 (diff)
Merge tag 'x86_core_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 updates from Borislav Petkov: - Turn the stack canary into a normal __percpu variable on 32-bit which gets rid of the LAZY_GS stuff and a lot of code. - Add an insn_decode() API which all users of the instruction decoder should preferrably use. Its goal is to keep the details of the instruction decoder away from its users and simplify and streamline how one decodes insns in the kernel. Convert its users to it. - kprobes improvements and fixes - Set the maximum DIE per package variable on Hygon - Rip out the dynamic NOP selection and simplify all the machinery around selecting NOPs. Use the simplified NOPs in objtool now too. - Add Xeon Sapphire Rapids to list of CPUs that support PPIN - Simplify the retpolines by folding the entire thing into an alternative now that objtool can handle alternatives with stack ops. Then, have objtool rewrite the call to the retpoline with the alternative which then will get patched at boot time. - Document Intel uarch per models in intel-family.h - Make Sub-NUMA Clustering topology the default and Cluster-on-Die the exception on Intel. * tag 'x86_core_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits) x86, sched: Treat Intel SNC topology as default, COD as exception x86/cpu: Comment Skylake server stepping too x86/cpu: Resort and comment Intel models objtool/x86: Rewrite retpoline thunk calls objtool: Skip magical retpoline .altinstr_replacement objtool: Cache instruction relocs objtool: Keep track of retpoline call sites objtool: Add elf_create_undef_symbol() objtool: Extract elf_symbol_add() objtool: Extract elf_strtab_concat() objtool: Create reloc sections implicitly objtool: Add elf_create_reloc() helper objtool: Rework the elf_rebuild_reloc_section() logic objtool: Fix static_call list generation objtool: Handle per arch retpoline naming objtool: Correctly handle retpoline thunk calls x86/retpoline: Simplify retpolines x86/alternatives: Optimize optimize_nops() x86: Add insn_decode_kernel() x86/kprobes: Move 'inline' to the beginning of the kprobe_is_ss() declaration ...
Diffstat (limited to 'tools/arch/x86/include/asm/nops.h')
-rw-r--r--tools/arch/x86/include/asm/nops.h81
1 files changed, 81 insertions, 0 deletions
diff --git a/tools/arch/x86/include/asm/nops.h b/tools/arch/x86/include/asm/nops.h
new file mode 100644
index 000000000000..c1e5e818ba16
--- /dev/null
+++ b/tools/arch/x86/include/asm/nops.h
@@ -0,0 +1,81 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_NOPS_H
+#define _ASM_X86_NOPS_H
+
+/*
+ * Define nops for use with alternative() and for tracing.
+ */
+
+#ifndef CONFIG_64BIT
+
+/*
+ * Generic 32bit nops from GAS:
+ *
+ * 1: nop
+ * 2: movl %esi,%esi
+ * 3: leal 0x0(%esi),%esi
+ * 4: leal 0x0(%esi,%eiz,1),%esi
+ * 5: leal %ds:0x0(%esi,%eiz,1),%esi
+ * 6: leal 0x0(%esi),%esi
+ * 7: leal 0x0(%esi,%eiz,1),%esi
+ * 8: leal %ds:0x0(%esi,%eiz,1),%esi
+ *
+ * Except 5 and 8, which are DS prefixed 4 and 7 resp, where GAS would emit 2
+ * nop instructions.
+ */
+#define BYTES_NOP1 0x90
+#define BYTES_NOP2 0x89,0xf6
+#define BYTES_NOP3 0x8d,0x76,0x00
+#define BYTES_NOP4 0x8d,0x74,0x26,0x00
+#define BYTES_NOP5 0x3e,BYTES_NOP4
+#define BYTES_NOP6 0x8d,0xb6,0x00,0x00,0x00,0x00
+#define BYTES_NOP7 0x8d,0xb4,0x26,0x00,0x00,0x00,0x00
+#define BYTES_NOP8 0x3e,BYTES_NOP7
+
+#else
+
+/*
+ * Generic 64bit nops from GAS:
+ *
+ * 1: nop
+ * 2: osp nop
+ * 3: nopl (%eax)
+ * 4: nopl 0x00(%eax)
+ * 5: nopl 0x00(%eax,%eax,1)
+ * 6: osp nopl 0x00(%eax,%eax,1)
+ * 7: nopl 0x00000000(%eax)
+ * 8: nopl 0x00000000(%eax,%eax,1)
+ */
+#define BYTES_NOP1 0x90
+#define BYTES_NOP2 0x66,BYTES_NOP1
+#define BYTES_NOP3 0x0f,0x1f,0x00
+#define BYTES_NOP4 0x0f,0x1f,0x40,0x00
+#define BYTES_NOP5 0x0f,0x1f,0x44,0x00,0x00
+#define BYTES_NOP6 0x66,BYTES_NOP5
+#define BYTES_NOP7 0x0f,0x1f,0x80,0x00,0x00,0x00,0x00
+#define BYTES_NOP8 0x0f,0x1f,0x84,0x00,0x00,0x00,0x00,0x00
+
+#endif /* CONFIG_64BIT */
+
+#ifdef __ASSEMBLY__
+#define _ASM_MK_NOP(x) .byte x
+#else
+#define _ASM_MK_NOP(x) ".byte " __stringify(x) "\n"
+#endif
+
+#define ASM_NOP1 _ASM_MK_NOP(BYTES_NOP1)
+#define ASM_NOP2 _ASM_MK_NOP(BYTES_NOP2)
+#define ASM_NOP3 _ASM_MK_NOP(BYTES_NOP3)
+#define ASM_NOP4 _ASM_MK_NOP(BYTES_NOP4)
+#define ASM_NOP5 _ASM_MK_NOP(BYTES_NOP5)
+#define ASM_NOP6 _ASM_MK_NOP(BYTES_NOP6)
+#define ASM_NOP7 _ASM_MK_NOP(BYTES_NOP7)
+#define ASM_NOP8 _ASM_MK_NOP(BYTES_NOP8)
+
+#define ASM_NOP_MAX 8
+
+#ifndef __ASSEMBLY__
+extern const unsigned char * const x86_nops[];
+#endif
+
+#endif /* _ASM_X86_NOPS_H */