Merge branch 'x86/cpu' into WIP.x86/core, to merge the NOP changes & resolve a semantic conflict

Conflict-merge this main commit in essence:

  a89dfde3dc3c: ("x86: Remove dynamic NOP selection")

With this upstream commit:

  b90829704780: ("bpf: Use NOP_ATOMIC5 instead of emit_nops(&prog, 5) for BPF_TRAMP_F_CALL_ORIG")

Semantic merge conflict:

  arch/x86/net/bpf_jit_comp.c

  - memcpy(prog, ideal_nops[NOP_ATOMIC5], X86_PATCH_SIZE);
  + memcpy(prog, x86_nops[5], X86_PATCH_SIZE);

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 21 insertions, 177 deletions

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index f902f28d9dff..80adf5a81a79 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -75,186 +75,30 @@ do {									\
 	}								\
 } while (0)
 
-/*
- * Each GENERIC_NOPX is of X bytes, and defined as an array of bytes
- * that correspond to that nop. Getting from one nop to the next, we
- * add to the array the offset that is equal to the sum of all sizes of
- * nops preceding the one we are after.
- *
- * Note: The GENERIC_NOP5_ATOMIC is at the end, as it breaks the
- * nice symmetry of sizes of the previous nops.
- */
-#if defined(GENERIC_NOP1) && !defined(CONFIG_X86_64)
-static const unsigned char intelnops[] =
+const unsigned char x86nops[] =
 {
-	GENERIC_NOP1,
-	GENERIC_NOP2,
-	GENERIC_NOP3,
-	GENERIC_NOP4,
-	GENERIC_NOP5,
-	GENERIC_NOP6,
-	GENERIC_NOP7,
-	GENERIC_NOP8,
-	GENERIC_NOP5_ATOMIC
-};
-static const unsigned char * const intel_nops[ASM_NOP_MAX+2] =
-{
-	NULL,
-	intelnops,
-	intelnops + 1,
-	intelnops + 1 + 2,
-	intelnops + 1 + 2 + 3,
-	intelnops + 1 + 2 + 3 + 4,
-	intelnops + 1 + 2 + 3 + 4 + 5,
-	intelnops + 1 + 2 + 3 + 4 + 5 + 6,
-	intelnops + 1 + 2 + 3 + 4 + 5 + 6 + 7,
-	intelnops + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8,
+	BYTES_NOP1,
+	BYTES_NOP2,
+	BYTES_NOP3,
+	BYTES_NOP4,
+	BYTES_NOP5,
+	BYTES_NOP6,
+	BYTES_NOP7,
+	BYTES_NOP8,
 };
-#endif
 
-#ifdef K8_NOP1
-static const unsigned char k8nops[] =
-{
-	K8_NOP1,
-	K8_NOP2,
-	K8_NOP3,
-	K8_NOP4,
-	K8_NOP5,
-	K8_NOP6,
-	K8_NOP7,
-	K8_NOP8,
-	K8_NOP5_ATOMIC
-};
-static const unsigned char * const k8_nops[ASM_NOP_MAX+2] =
-{
-	NULL,
-	k8nops,
-	k8nops + 1,
-	k8nops + 1 + 2,
-	k8nops + 1 + 2 + 3,
-	k8nops + 1 + 2 + 3 + 4,
-	k8nops + 1 + 2 + 3 + 4 + 5,
-	k8nops + 1 + 2 + 3 + 4 + 5 + 6,
-	k8nops + 1 + 2 + 3 + 4 + 5 + 6 + 7,
-	k8nops + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8,
-};
-#endif
-
-#if defined(K7_NOP1) && !defined(CONFIG_X86_64)
-static const unsigned char k7nops[] =
-{
-	K7_NOP1,
-	K7_NOP2,
-	K7_NOP3,
-	K7_NOP4,
-	K7_NOP5,
-	K7_NOP6,
-	K7_NOP7,
-	K7_NOP8,
-	K7_NOP5_ATOMIC
-};
-static const unsigned char * const k7_nops[ASM_NOP_MAX+2] =
-{
-	NULL,
-	k7nops,
-	k7nops + 1,
-	k7nops + 1 + 2,
-	k7nops + 1 + 2 + 3,
-	k7nops + 1 + 2 + 3 + 4,
-	k7nops + 1 + 2 + 3 + 4 + 5,
-	k7nops + 1 + 2 + 3 + 4 + 5 + 6,
-	k7nops + 1 + 2 + 3 + 4 + 5 + 6 + 7,
-	k7nops + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8,
-};
-#endif
-
-#ifdef P6_NOP1
-static const unsigned char p6nops[] =
-{
-	P6_NOP1,
-	P6_NOP2,
-	P6_NOP3,
-	P6_NOP4,
-	P6_NOP5,
-	P6_NOP6,
-	P6_NOP7,
-	P6_NOP8,
-	P6_NOP5_ATOMIC
-};
-static const unsigned char * const p6_nops[ASM_NOP_MAX+2] =
+const unsigned char * const x86_nops[ASM_NOP_MAX+1] =
 {
 	NULL,
-	p6nops,
-	p6nops + 1,
-	p6nops + 1 + 2,
-	p6nops + 1 + 2 + 3,
-	p6nops + 1 + 2 + 3 + 4,
-	p6nops + 1 + 2 + 3 + 4 + 5,
-	p6nops + 1 + 2 + 3 + 4 + 5 + 6,
-	p6nops + 1 + 2 + 3 + 4 + 5 + 6 + 7,
-	p6nops + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8,
+	x86nops,
+	x86nops + 1,
+	x86nops + 1 + 2,
+	x86nops + 1 + 2 + 3,
+	x86nops + 1 + 2 + 3 + 4,
+	x86nops + 1 + 2 + 3 + 4 + 5,
+	x86nops + 1 + 2 + 3 + 4 + 5 + 6,
+	x86nops + 1 + 2 + 3 + 4 + 5 + 6 + 7,
 };
-#endif
-
-/* Initialize these to a safe default */
-#ifdef CONFIG_X86_64
-const unsigned char * const *ideal_nops = p6_nops;
-#else
-const unsigned char * const *ideal_nops = intel_nops;
-#endif
-
-void __init arch_init_ideal_nops(void)
-{
-	switch (boot_cpu_data.x86_vendor) {
-	case X86_VENDOR_INTEL:
-		/*
-		 * Due to a decoder implementation quirk, some
-		 * specific Intel CPUs actually perform better with
-		 * the "k8_nops" than with the SDM-recommended NOPs.
-		 */
-		if (boot_cpu_data.x86 == 6 &&
-		    boot_cpu_data.x86_model >= 0x0f &&
-		    boot_cpu_data.x86_model != 0x1c &&
-		    boot_cpu_data.x86_model != 0x26 &&
-		    boot_cpu_data.x86_model != 0x27 &&
-		    boot_cpu_data.x86_model < 0x30) {
-			ideal_nops = k8_nops;
-		} else if (boot_cpu_has(X86_FEATURE_NOPL)) {
-			   ideal_nops = p6_nops;
-		} else {
-#ifdef CONFIG_X86_64
-			ideal_nops = k8_nops;
-#else
-			ideal_nops = intel_nops;
-#endif
-		}
-		break;
-
-	case X86_VENDOR_HYGON:
-		ideal_nops = p6_nops;
-		return;
-
-	case X86_VENDOR_AMD:
-		if (boot_cpu_data.x86 > 0xf) {
-			ideal_nops = p6_nops;
-			return;
-		}
-
-		fallthrough;
-
-	default:
-#ifdef CONFIG_X86_64
-		ideal_nops = k8_nops;
-#else
-		if (boot_cpu_has(X86_FEATURE_K8))
-			ideal_nops = k8_nops;
-		else if (boot_cpu_has(X86_FEATURE_K7))
-			ideal_nops = k7_nops;
-		else
-			ideal_nops = intel_nops;
-#endif
-	}
-}
 
 /* Use this to add nops to a buffer, then text_poke the whole buffer. */
 static void __init_or_module add_nops(void *insns, unsigned int len)
@@ -263,7 +107,7 @@ static void __init_or_module add_nops(void *insns, unsigned int len)
 		unsigned int noplen = len;
 		if (noplen > ASM_NOP_MAX)
 			noplen = ASM_NOP_MAX;
-		memcpy(insns, ideal_nops[noplen], noplen);
+		memcpy(insns, x86_nops[noplen], noplen);
 		insns += noplen;
 		len -= noplen;
 	}
@@ -1338,13 +1182,13 @@ static void text_poke_loc_init(struct text_poke_loc *tp, void *addr,
 	default: /* assume NOP */
 		switch (len) {
 		case 2: /* NOP2 -- emulate as JMP8+0 */
-			BUG_ON(memcmp(emulate, ideal_nops[len], len));
+			BUG_ON(memcmp(emulate, x86_nops[len], len));
 			tp->opcode = JMP8_INSN_OPCODE;
 			tp->rel32 = 0;
 			break;
 
 		case 5: /* NOP5 -- emulate as JMP32+0 */
-			BUG_ON(memcmp(emulate, ideal_nops[NOP_ATOMIC5], len));
+			BUG_ON(memcmp(emulate, x86_nops[len], len));
 			tp->opcode = JMP32_INSN_OPCODE;
 			tp->rel32 = 0;
 			break;