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
  ...

1 files changed, 182 insertions, 48 deletions

diff --git a/arch/x86/lib/insn.c b/arch/x86/lib/insn.c
index 435630a6ec97..058f19b20465 100644
--- a/arch/x86/lib/insn.c
+++ b/arch/x86/lib/insn.c
@@ -11,10 +11,13 @@
 #else
 #include <string.h>
 #endif
-#include <asm/inat.h>
-#include <asm/insn.h>
+#include <asm/inat.h> /*__ignore_sync_check__ */
+#include <asm/insn.h> /* __ignore_sync_check__ */
 
-#include <asm/emulate_prefix.h>
+#include <linux/errno.h>
+#include <linux/kconfig.h>
+
+#include <asm/emulate_prefix.h> /* __ignore_sync_check__ */
 
 #define leXX_to_cpu(t, r)						\
 ({									\
@@ -51,6 +54,7 @@
  * insn_init() - initialize struct insn
  * @insn:	&struct insn to be initialized
  * @kaddr:	address (in kernel memory) of instruction (or copy thereof)
+ * @buf_len:	length of the insn buffer at @kaddr
  * @x86_64:	!0 for 64-bit kernel or 64-bit app
  */
 void insn_init(struct insn *insn, const void *kaddr, int buf_len, int x86_64)
@@ -111,8 +115,12 @@ static void insn_get_emulate_prefix(struct insn *insn)
  * Populates the @insn->prefixes bitmap, and updates @insn->next_byte
  * to point to the (first) opcode.  No effect if @insn->prefixes.got
  * is already set.
+ *
+ * * Returns:
+ * 0:  on success
+ * < 0: on error
  */
-void insn_get_prefixes(struct insn *insn)
+int insn_get_prefixes(struct insn *insn)
 {
 	struct insn_field *prefixes = &insn->prefixes;
 	insn_attr_t attr;
@@ -120,7 +128,7 @@ void insn_get_prefixes(struct insn *insn)
 	int i, nb;
 
 	if (prefixes->got)
-		return;
+		return 0;
 
 	insn_get_emulate_prefix(insn);
 
@@ -230,8 +238,10 @@ vex_end:
 
 	prefixes->got = 1;
 
+	return 0;
+
 err_out:
-	return;
+	return -ENODATA;
 }
 
 /**
@@ -243,16 +253,25 @@ err_out:
  * If necessary, first collects any preceding (prefix) bytes.
  * Sets @insn->opcode.value = opcode1.  No effect if @insn->opcode.got
  * is already 1.
+ *
+ * Returns:
+ * 0:  on success
+ * < 0: on error
  */
-void insn_get_opcode(struct insn *insn)
+int insn_get_opcode(struct insn *insn)
 {
 	struct insn_field *opcode = &insn->opcode;
+	int pfx_id, ret;
 	insn_byte_t op;
-	int pfx_id;
+
 	if (opcode->got)
-		return;
-	if (!insn->prefixes.got)
-		insn_get_prefixes(insn);
+		return 0;
+
+	if (!insn->prefixes.got) {
+		ret = insn_get_prefixes(insn);
+		if (ret)
+			return ret;
+	}
 
 	/* Get first opcode */
 	op = get_next(insn_byte_t, insn);
@@ -267,9 +286,13 @@ void insn_get_opcode(struct insn *insn)
 		insn->attr = inat_get_avx_attribute(op, m, p);
 		if ((inat_must_evex(insn->attr) && !insn_is_evex(insn)) ||
 		    (!inat_accept_vex(insn->attr) &&
-		     !inat_is_group(insn->attr)))
-			insn->attr = 0;	/* This instruction is bad */
-		goto end;	/* VEX has only 1 byte for opcode */
+		     !inat_is_group(insn->attr))) {
+			/* This instruction is bad */
+			insn->attr = 0;
+			return -EINVAL;
+		}
+		/* VEX has only 1 byte for opcode */
+		goto end;
 	}
 
 	insn->attr = inat_get_opcode_attribute(op);
@@ -280,13 +303,18 @@ void insn_get_opcode(struct insn *insn)
 		pfx_id = insn_last_prefix_id(insn);
 		insn->attr = inat_get_escape_attribute(op, pfx_id, insn->attr);
 	}
-	if (inat_must_vex(insn->attr))
-		insn->attr = 0;	/* This instruction is bad */
+
+	if (inat_must_vex(insn->attr)) {
+		/* This instruction is bad */
+		insn->attr = 0;
+		return -EINVAL;
+	}
 end:
 	opcode->got = 1;
+	return 0;
 
 err_out:
-	return;
+	return -ENODATA;
 }
 
 /**
@@ -296,15 +324,25 @@ err_out:
  * Populates @insn->modrm and updates @insn->next_byte to point past the
  * ModRM byte, if any.  If necessary, first collects the preceding bytes
  * (prefixes and opcode(s)).  No effect if @insn->modrm.got is already 1.
+ *
+ * Returns:
+ * 0:  on success
+ * < 0: on error
  */
-void insn_get_modrm(struct insn *insn)
+int insn_get_modrm(struct insn *insn)
 {
 	struct insn_field *modrm = &insn->modrm;
 	insn_byte_t pfx_id, mod;
+	int ret;
+
 	if (modrm->got)
-		return;
-	if (!insn->opcode.got)
-		insn_get_opcode(insn);
+		return 0;
+
+	if (!insn->opcode.got) {
+		ret = insn_get_opcode(insn);
+		if (ret)
+			return ret;
+	}
 
 	if (inat_has_modrm(insn->attr)) {
 		mod = get_next(insn_byte_t, insn);
@@ -313,17 +351,22 @@ void insn_get_modrm(struct insn *insn)
 			pfx_id = insn_last_prefix_id(insn);
 			insn->attr = inat_get_group_attribute(mod, pfx_id,
 							      insn->attr);
-			if (insn_is_avx(insn) && !inat_accept_vex(insn->attr))
-				insn->attr = 0;	/* This is bad */
+			if (insn_is_avx(insn) && !inat_accept_vex(insn->attr)) {
+				/* Bad insn */
+				insn->attr = 0;
+				return -EINVAL;
+			}
 		}
 	}
 
 	if (insn->x86_64 && inat_is_force64(insn->attr))
 		insn->opnd_bytes = 8;
+
 	modrm->got = 1;
+	return 0;
 
 err_out:
-	return;
+	return -ENODATA;
 }
 
 
@@ -337,11 +380,16 @@ err_out:
 int insn_rip_relative(struct insn *insn)
 {
 	struct insn_field *modrm = &insn->modrm;
+	int ret;
 
 	if (!insn->x86_64)
 		return 0;
-	if (!modrm->got)
-		insn_get_modrm(insn);
+
+	if (!modrm->got) {
+		ret = insn_get_modrm(insn);
+		if (ret)
+			return 0;
+	}
 	/*
 	 * For rip-relative instructions, the mod field (top 2 bits)
 	 * is zero and the r/m field (bottom 3 bits) is 0x5.
@@ -355,15 +403,25 @@ int insn_rip_relative(struct insn *insn)
  *
  * If necessary, first collects the instruction up to and including the
  * ModRM byte.
+ *
+ * Returns:
+ * 0: if decoding succeeded
+ * < 0: otherwise.
  */
-void insn_get_sib(struct insn *insn)
+int insn_get_sib(struct insn *insn)
 {
 	insn_byte_t modrm;
+	int ret;
 
 	if (insn->sib.got)
-		return;
-	if (!insn->modrm.got)
-		insn_get_modrm(insn);
+		return 0;
+
+	if (!insn->modrm.got) {
+		ret = insn_get_modrm(insn);
+		if (ret)
+			return ret;
+	}
+
 	if (insn->modrm.nbytes) {
 		modrm = insn->modrm.bytes[0];
 		if (insn->addr_bytes != 2 &&
@@ -374,8 +432,10 @@ void insn_get_sib(struct insn *insn)
 	}
 	insn->sib.got = 1;
 
+	return 0;
+
 err_out:
-	return;
+	return -ENODATA;
 }
 
 
@@ -386,15 +446,25 @@ err_out:
  * If necessary, first collects the instruction up to and including the
  * SIB byte.
  * Displacement value is sign-expanded.
+ *
+ * * Returns:
+ * 0: if decoding succeeded
+ * < 0: otherwise.
  */
-void insn_get_displacement(struct insn *insn)
+int insn_get_displacement(struct insn *insn)
 {
 	insn_byte_t mod, rm, base;
+	int ret;
 
 	if (insn->displacement.got)
-		return;
-	if (!insn->sib.got)
-		insn_get_sib(insn);
+		return 0;
+
+	if (!insn->sib.got) {
+		ret = insn_get_sib(insn);
+		if (ret)
+			return ret;
+	}
+
 	if (insn->modrm.nbytes) {
 		/*
 		 * Interpreting the modrm byte:
@@ -436,9 +506,10 @@ void insn_get_displacement(struct insn *insn)
 	}
 out:
 	insn->displacement.got = 1;
+	return 0;
 
 err_out:
-	return;
+	return -ENODATA;
 }
 
 /* Decode moffset16/32/64. Return 0 if failed */
@@ -537,20 +608,30 @@ err_out:
 }
 
 /**
- * insn_get_immediate() - Get the immediates of instruction
+ * insn_get_immediate() - Get the immediate in an instruction
  * @insn:	&struct insn containing instruction
  *
  * If necessary, first collects the instruction up to and including the
  * displacement bytes.
  * Basically, most of immediates are sign-expanded. Unsigned-value can be
- * get by bit masking with ((1 << (nbytes * 8)) - 1)
+ * computed by bit masking with ((1 << (nbytes * 8)) - 1)
+ *
+ * Returns:
+ * 0:  on success
+ * < 0: on error
  */
-void insn_get_immediate(struct insn *insn)
+int insn_get_immediate(struct insn *insn)
 {
+	int ret;
+
 	if (insn->immediate.got)
-		return;
-	if (!insn->displacement.got)
-		insn_get_displacement(insn);
+		return 0;
+
+	if (!insn->displacement.got) {
+		ret = insn_get_displacement(insn);
+		if (ret)
+			return ret;
+	}
 
 	if (inat_has_moffset(insn->attr)) {
 		if (!__get_moffset(insn))
@@ -597,9 +678,10 @@ void insn_get_immediate(struct insn *insn)
 	}
 done:
 	insn->immediate.got = 1;
+	return 0;
 
 err_out:
-	return;
+	return -ENODATA;
 }
 
 /**
@@ -608,13 +690,65 @@ err_out:
  *
  * If necessary, first collects the instruction up to and including the
  * immediates bytes.
- */
-void insn_get_length(struct insn *insn)
+ *
+ * Returns:
+ *  - 0 on success
+ *  - < 0 on error
+*/
+int insn_get_length(struct insn *insn)
 {
+	int ret;
+
 	if (insn->length)
-		return;
-	if (!insn->immediate.got)
-		insn_get_immediate(insn);
+		return 0;
+
+	if (!insn->immediate.got) {
+		ret = insn_get_immediate(insn);
+		if (ret)
+			return ret;
+	}
+
 	insn->length = (unsigned char)((unsigned long)insn->next_byte
 				     - (unsigned long)insn->kaddr);
+
+	return 0;
+}
+
+/* Ensure this instruction is decoded completely */
+static inline int insn_complete(struct insn *insn)
+{
+	return insn->opcode.got && insn->modrm.got && insn->sib.got &&
+		insn->displacement.got && insn->immediate.got;
+}
+
+/**
+ * insn_decode() - Decode an x86 instruction
+ * @insn:	&struct insn to be initialized
+ * @kaddr:	address (in kernel memory) of instruction (or copy thereof)
+ * @buf_len:	length of the insn buffer at @kaddr
+ * @m:		insn mode, see enum insn_mode
+ *
+ * Returns:
+ * 0: if decoding succeeded
+ * < 0: otherwise.
+ */
+int insn_decode(struct insn *insn, const void *kaddr, int buf_len, enum insn_mode m)
+{
+	int ret;
+
+/* #define INSN_MODE_KERN	-1 __ignore_sync_check__ mode is only valid in the kernel */
+
+	if (m == INSN_MODE_KERN)
+		insn_init(insn, kaddr, buf_len, IS_ENABLED(CONFIG_X86_64));
+	else
+		insn_init(insn, kaddr, buf_len, m == INSN_MODE_64);
+
+	ret = insn_get_length(insn);
+	if (ret)
+		return ret;
+
+	if (insn_complete(insn))
+		return 0;
+
+	return -EINVAL;
 }