Merge branch 'core-objtool-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull objtool updates from Ingo Molnar:
 "The biggest changes in this cycle were the vmlinux.o optimizations by
   Peter Zijlstra, which are preparatory and optimization work to run
   objtool against the much richer vmlinux.o object file, to perform
   new, whole-program section based logic. That work exposed a handful
   of problems with the existing code, which fixes and optimizations are
   merged here. The complete 'vmlinux.o and noinstr' work is still work
   in progress, targeted for v5.8.

  There's also assorted fixes and enhancements from Josh Poimboeuf.

  In particular I'd like to draw attention to commit 644592d3,
  which turns fatal objtool errors into failed kernel builds. This
  behavior is IMO now justified on multiple grounds (it's easy currently
  to not notice an essentially corrupted kernel build), and the commit
  has been in -next testing for several weeks, but there could still be
  build failures with old or weird toolchains. Should that be widespread
  or high profile enough then I'd suggest a quick revert, to not hold up
  the merge window"

* 'core-objtool-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits)
  objtool: Re-arrange validate_functions()
  objtool: Optimize find_rela_by_dest_range()
  objtool: Delete cleanup()
  objtool: Optimize read_sections()
  objtool: Optimize find_symbol_by_name()
  objtool: Resize insn_hash
  objtool: Rename find_containing_func()
  objtool: Optimize find_symbol_*() and read_symbols()
  objtool: Optimize find_section_by_name()
  objtool: Optimize find_section_by_index()
  objtool: Add a statistics mode
  objtool: Optimize find_symbol_by_index()
  x86/kexec: Make relocate_kernel_64.S objtool clean
  x86/kexec: Use RIP relative addressing
  objtool: Rename func_for_each_insn_all()
  objtool: Rename func_for_each_insn()
  objtool: Introduce validate_return()
  objtool: Improve call destination function detection
  objtool: Fix clang switch table edge case
  objtool: Add relocation check for alternative sections
  ...

arch/x86/kernel/Makefile

@@ -28,7 +28,6 @@ KASAN_SANITIZE_dumpstack_$(BITS).o			:= n
 KASAN_SANITIZE_stacktrace.o				:= n
 KASAN_SANITIZE_paravirt.o				:= n
 
-OBJECT_FILES_NON_STANDARD_relocate_kernel_$(BITS).o	:= y
 OBJECT_FILES_NON_STANDARD_test_nx.o			:= y
 OBJECT_FILES_NON_STANDARD_paravirt_patch.o		:= y
 

arch/x86/kernel/relocate_kernel_64.S

@@ -9,6 +9,8 @@
 #include <asm/kexec.h>
 #include <asm/processor-flags.h>
 #include <asm/pgtable_types.h>
+#include <asm/nospec-branch.h>
+#include <asm/unwind_hints.h>
 
 /*
  * Must be relocatable PIC code callable as a C function
@@ -39,6 +41,7 @@
 	.align PAGE_SIZE
 	.code64
 SYM_CODE_START_NOALIGN(relocate_kernel)
+	UNWIND_HINT_EMPTY
 	/*
 	 * %rdi indirection_page
 	 * %rsi page_list
@@ -105,6 +108,7 @@ SYM_CODE_START_NOALIGN(relocate_kernel)
 SYM_CODE_END(relocate_kernel)
 
 SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
+	UNWIND_HINT_EMPTY
 	/* set return address to 0 if not preserving context */
 	pushq	$0
 	/* store the start address on the stack */
@@ -192,14 +196,12 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
 1:
 	popq	%rdx
 	leaq	PAGE_SIZE(%r10), %rsp
+	ANNOTATE_RETPOLINE_SAFE
 	call	*%rdx
 
 	/* get the re-entry point of the peer system */
 	movq	0(%rsp), %rbp
-	call	1f
-1:
-	popq	%r8
-	subq	$(1b - relocate_kernel), %r8
+	leaq	relocate_kernel(%rip), %r8
 	movq	CP_PA_SWAP_PAGE(%r8), %r10
 	movq	CP_PA_BACKUP_PAGES_MAP(%r8), %rdi
 	movq	CP_PA_TABLE_PAGE(%r8), %rax
@@ -212,6 +214,7 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
 SYM_CODE_END(identity_mapped)
 
 SYM_CODE_START_LOCAL_NOALIGN(virtual_mapped)
+	UNWIND_HINT_EMPTY
 	movq	RSP(%r8), %rsp
 	movq	CR4(%r8), %rax
 	movq	%rax, %cr4
@@ -233,6 +236,7 @@ SYM_CODE_END(virtual_mapped)
 
 	/* Do the copies */
 SYM_CODE_START_LOCAL_NOALIGN(swap_pages)
+	UNWIND_HINT_EMPTY
 	movq	%rdi, %rcx 	/* Put the page_list in %rcx */
 	xorl	%edi, %edi
 	xorl	%esi, %esi

tools/objtool/Build

@@ -11,6 +11,7 @@ objtool-y += objtool.o
 objtool-y += libstring.o
 objtool-y += libctype.o
 objtool-y += str_error_r.o
+objtool-y += librbtree.o
 
 CFLAGS += -I$(srctree)/tools/lib
 
@@ -25,3 +26,7 @@ $(OUTPUT)libctype.o: ../lib/ctype.c FORCE
 $(OUTPUT)str_error_r.o: ../lib/str_error_r.c FORCE
 	$(call rule_mkdir)
 	$(call if_changed_dep,cc_o_c)
+
+$(OUTPUT)librbtree.o: ../lib/rbtree.c FORCE
+	$(call rule_mkdir)
+	$(call if_changed_dep,cc_o_c)

tools/objtool/builtin-check.c

@@ -17,7 +17,7 @@
 #include "builtin.h"
 #include "check.h"
 
-bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess;
+bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess, stats;
 
 static const char * const check_usage[] = {
 	"objtool check [<options>] file.o",
@@ -31,6 +31,7 @@ const struct option check_options[] = {
 	OPT_BOOLEAN('m', "module", &module, "Indicates the object will be part of a kernel module"),
 	OPT_BOOLEAN('b', "backtrace", &backtrace, "unwind on error"),
 	OPT_BOOLEAN('a', "uaccess", &uaccess, "enable uaccess checking"),
+	OPT_BOOLEAN('s', "stats", &stats, "print statistics"),
 	OPT_END(),
 };
 

tools/objtool/builtin.h

@@ -8,7 +8,7 @@
 #include <subcmd/parse-options.h>
 
 extern const struct option check_options[];
-extern bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess;
+extern bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess, stats;
 
 extern int cmd_check(int argc, const char **argv);
 extern int cmd_orc(int argc, const char **argv);

tools/objtool/check.c

@@ -72,22 +72,22 @@ static struct instruction *next_insn_same_func(struct objtool_file *file,
 	return find_insn(file, func->cfunc->sec, func->cfunc->offset);
 }
 
-#define func_for_each_insn_all(file, func, insn)			\
+#define func_for_each_insn(file, func, insn)				\
 	for (insn = find_insn(file, func->sec, func->offset);		\
 	     insn;							\
 	     insn = next_insn_same_func(file, insn))
 
-#define func_for_each_insn(file, func, insn)				\
-	for (insn = find_insn(file, func->sec, func->offset);		\
+#define sym_for_each_insn(file, sym, insn)				\
+	for (insn = find_insn(file, sym->sec, sym->offset);		\
 	     insn && &insn->list != &file->insn_list &&			\
-		insn->sec == func->sec &&				\
-		insn->offset < func->offset + func->len;		\
+		insn->sec == sym->sec &&				\
+		insn->offset < sym->offset + sym->len;			\
 	     insn = list_next_entry(insn, list))
 
-#define func_for_each_insn_continue_reverse(file, func, insn)		\
+#define sym_for_each_insn_continue_reverse(file, sym, insn)		\
 	for (insn = list_prev_entry(insn, list);			\
 	     &insn->list != &file->insn_list &&				\
-		insn->sec == func->sec && insn->offset >= func->offset;	\
+		insn->sec == sym->sec && insn->offset >= sym->offset;	\
 	     insn = list_prev_entry(insn, list))
 
 #define sec_for_each_insn_from(file, insn)				\
@@ -97,14 +97,19 @@ static struct instruction *next_insn_same_func(struct objtool_file *file,
 	for (insn = next_insn_same_sec(file, insn); insn;		\
 	     insn = next_insn_same_sec(file, insn))
 
+static bool is_static_jump(struct instruction *insn)
+{
+	return insn->type == INSN_JUMP_CONDITIONAL ||
+	       insn->type == INSN_JUMP_UNCONDITIONAL;
+}
+
 static bool is_sibling_call(struct instruction *insn)
 {
 	/* An indirect jump is either a sibling call or a jump to a table. */
 	if (insn->type == INSN_JUMP_DYNAMIC)
 		return list_empty(&insn->alts);
 
-	if (insn->type != INSN_JUMP_CONDITIONAL &&
-	    insn->type != INSN_JUMP_UNCONDITIONAL)
+	if (!is_static_jump(insn))
 		return false;
 
 	/* add_jump_destinations() sets insn->call_dest for sibling calls. */
@@ -165,7 +170,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
 	if (!insn->func)
 		return false;
 
-	func_for_each_insn_all(file, func, insn) {
+	func_for_each_insn(file, func, insn) {
 		empty = false;
 
 		if (insn->type == INSN_RETURN)
@@ -180,7 +185,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
 	 * case, the function's dead-end status depends on whether the target
 	 * of the sibling call returns.
 	 */
-	func_for_each_insn_all(file, func, insn) {
+	func_for_each_insn(file, func, insn) {
 		if (is_sibling_call(insn)) {
 			struct instruction *dest = insn->jump_dest;
 
@@ -234,6 +239,7 @@ static int decode_instructions(struct objtool_file *file)
 	struct symbol *func;
 	unsigned long offset;
 	struct instruction *insn;
+	unsigned long nr_insns = 0;
 	int ret;
 
 	for_each_sec(file, sec) {
@@ -269,6 +275,7 @@ static int decode_instructions(struct objtool_file *file)
 
 			hash_add(file->insn_hash, &insn->hash, insn->offset);
 			list_add_tail(&insn->list, &file->insn_list);
+			nr_insns++;
 		}
 
 		list_for_each_entry(func, &sec->symbol_list, list) {
@@ -281,11 +288,14 @@ static int decode_instructions(struct objtool_file *file)
 				return -1;
 			}
 
-			func_for_each_insn(file, func, insn)
+			sym_for_each_insn(file, func, insn)
 				insn->func = func;
 		}
 	}
 
+	if (stats)
+		printf("nr_insns: %lu\n", nr_insns);
+
 	return 0;
 
 err:
@@ -415,8 +425,8 @@ static void add_ignores(struct objtool_file *file)
 			break;
 
 		case STT_SECTION:
-			func = find_symbol_by_offset(rela->sym->sec, rela->addend);
-			if (!func || func->type != STT_FUNC)
+			func = find_func_by_offset(rela->sym->sec, rela->addend);
+			if (!func)
 				continue;
 			break;
 
@@ -425,7 +435,7 @@ static void add_ignores(struct objtool_file *file)
 			continue;
 		}
 
-		func_for_each_insn_all(file, func, insn)
+		func_for_each_insn(file, func, insn)
 			insn->ignore = true;
 	}
 }
@@ -553,15 +563,14 @@ static int add_jump_destinations(struct objtool_file *file)
 	unsigned long dest_off;
 
 	for_each_insn(file, insn) {
-		if (insn->type != INSN_JUMP_CONDITIONAL &&
-		    insn->type != INSN_JUMP_UNCONDITIONAL)
+		if (!is_static_jump(insn))
 			continue;
 
 		if (insn->ignore || insn->offset == FAKE_JUMP_OFFSET)
 			continue;
 
-		rela = find_rela_by_dest_range(insn->sec, insn->offset,
-					       insn->len);
+		rela = find_rela_by_dest_range(file->elf, insn->sec,
+					       insn->offset, insn->len);
 		if (!rela) {
 			dest_sec = insn->sec;
 			dest_off = insn->offset + insn->len + insn->immediate;
@@ -657,14 +666,18 @@ static int add_call_destinations(struct objtool_file *file)
 		if (insn->type != INSN_CALL)
 			continue;
 
-		rela = find_rela_by_dest_range(insn->sec, insn->offset,
-					       insn->len);
+		rela = find_rela_by_dest_range(file->elf, insn->sec,
+					       insn->offset, insn->len);
 		if (!rela) {
 			dest_off = insn->offset + insn->len + insn->immediate;
-			insn->call_dest = find_symbol_by_offset(insn->sec,
-								dest_off);
+			insn->call_dest = find_func_by_offset(insn->sec, dest_off);
+			if (!insn->call_dest)
+				insn->call_dest = find_symbol_by_offset(insn->sec, dest_off);
 
-			if (!insn->call_dest && !insn->ignore) {
+			if (insn->ignore)
+				continue;
+
+			if (!insn->call_dest) {
 				WARN_FUNC("unsupported intra-function call",
 					  insn->sec, insn->offset);
 				if (retpoline)
@@ -672,11 +685,16 @@ static int add_call_destinations(struct objtool_file *file)
 				return -1;
 			}
 
+			if (insn->func && insn->call_dest->type != STT_FUNC) {
+				WARN_FUNC("unsupported call to non-function",
+					  insn->sec, insn->offset);
+				return -1;
+			}
+
 		} else if (rela->sym->type == STT_SECTION) {
-			insn->call_dest = find_symbol_by_offset(rela->sym->sec,
-								rela->addend+4);
-			if (!insn->call_dest ||
-			    insn->call_dest->type != STT_FUNC) {
+			insn->call_dest = find_func_by_offset(rela->sym->sec,
+							      rela->addend+4);
+			if (!insn->call_dest) {
 				WARN_FUNC("can't find call dest symbol at %s+0x%x",
 					  insn->sec, insn->offset,
 					  rela->sym->sec->name,
@@ -764,8 +782,28 @@ static int handle_group_alt(struct objtool_file *file,
 		insn->ignore = orig_insn->ignore_alts;
 		insn->func = orig_insn->func;
 
-		if (insn->type != INSN_JUMP_CONDITIONAL &&
-		    insn->type != INSN_JUMP_UNCONDITIONAL)
+		/*
+		 * Since alternative replacement code is copy/pasted by the
+		 * kernel after applying relocations, generally such code can't
+		 * have relative-address relocation references to outside the
+		 * .altinstr_replacement section, unless the arch's
+		 * alternatives code can adjust the relative offsets
+		 * accordingly.
+		 *
+		 * The x86 alternatives code adjusts the offsets only when it
+		 * encounters a branch instruction at the very beginning of the
+		 * replacement group.
+		 */
+		if ((insn->offset != special_alt->new_off ||
+		    (insn->type != INSN_CALL && !is_static_jump(insn))) &&
+		    find_rela_by_dest_range(file->elf, insn->sec, insn->offset, insn->len)) {
+
+			WARN_FUNC("unsupported relocation in alternatives section",
+				  insn->sec, insn->offset);
+			return -1;
+		}
+
+		if (!is_static_jump(insn))
 			continue;
 
 		if (!insn->immediate)
@@ -1001,7 +1039,7 @@ static struct rela *find_jump_table(struct objtool_file *file,
 				      struct instruction *insn)
 {
 	struct rela *text_rela, *table_rela;
-	struct instruction *orig_insn = insn;
+	struct instruction *dest_insn, *orig_insn = insn;
 	struct section *table_sec;
 	unsigned long table_offset;
 
@@ -1028,8 +1066,8 @@ static struct rela *find_jump_table(struct objtool_file *file,
 		    break;
 
 		/* look for a relocation which references .rodata */
-		text_rela = find_rela_by_dest_range(insn->sec, insn->offset,
-						    insn->len);
+		text_rela = find_rela_by_dest_range(file->elf, insn->sec,
+						    insn->offset, insn->len);
 		if (!text_rela || text_rela->sym->type != STT_SECTION ||
 		    !text_rela->sym->sec->rodata)
 			continue;
@@ -1053,10 +1091,17 @@ static struct rela *find_jump_table(struct objtool_file *file,
 		    strcmp(table_sec->name, C_JUMP_TABLE_SECTION))
 			continue;
 
-		/* Each table entry has a rela associated with it. */
-		table_rela = find_rela_by_dest(table_sec, table_offset);
+		/*
+		 * Each table entry has a rela associated with it.  The rela
+		 * should reference text in the same function as the original
+		 * instruction.
+		 */
+		table_rela = find_rela_by_dest(file->elf, table_sec, table_offset);
 		if (!table_rela)
 			continue;
+		dest_insn = find_insn(file, table_rela->sym->sec, table_rela->addend);
+		if (!dest_insn || !dest_insn->func || dest_insn->func->pfunc != func)
+			continue;
 
 		/*
 		 * Use of RIP-relative switch jumps is quite rare, and
@@ -1082,7 +1127,7 @@ static void mark_func_jump_tables(struct objtool_file *file,
 	struct instruction *insn, *last = NULL;
 	struct rela *rela;
 
-	func_for_each_insn_all(file, func, insn) {
+	func_for_each_insn(file, func, insn) {
 		if (!last)
 			last = insn;
 
@@ -1117,7 +1162,7 @@ static int add_func_jump_tables(struct objtool_file *file,
 	struct instruction *insn;
 	int ret;
 
-	func_for_each_insn_all(file, func, insn) {
+	func_for_each_insn(file, func, insn) {
 		if (!insn->jump_table)
 			continue;
 
@@ -1187,7 +1232,7 @@ static int read_unwind_hints(struct objtool_file *file)
 	for (i = 0; i < sec->len / sizeof(struct unwind_hint); i++) {
 		hint = (struct unwind_hint *)sec->data->d_buf + i;
 
-		rela = find_rela_by_dest(sec, i * sizeof(*hint));
+		rela = find_rela_by_dest(file->elf, sec, i * sizeof(*hint));
 		if (!rela) {
 			WARN("can't find rela for unwind_hints[%d]", i);
 			return -1;
@@ -1935,6 +1980,41 @@ static int validate_sibling_call(struct instruction *insn, struct insn_state *st
 	return validate_call(insn, state);
 }
 
+static int validate_return(struct symbol *func, struct instruction *insn, struct insn_state *state)
+{
+	if (state->uaccess && !func_uaccess_safe(func)) {
+		WARN_FUNC("return with UACCESS enabled",
+			  insn->sec, insn->offset);
+		return 1;
+	}
+
+	if (!state->uaccess && func_uaccess_safe(func)) {
+		WARN_FUNC("return with UACCESS disabled from a UACCESS-safe function",
+			  insn->sec, insn->offset);
+		return 1;
+	}
+
+	if (state->df) {
+		WARN_FUNC("return with DF set",
+			  insn->sec, insn->offset);
+		return 1;
+	}
+
+	if (func && has_modified_stack_frame(state)) {
+		WARN_FUNC("return with modified stack frame",
+			  insn->sec, insn->offset);
+		return 1;
+	}
+
+	if (state->bp_scratch) {
+		WARN("%s uses BP as a scratch register",
+		     func->name);
+		return 1;
+	}
+
+	return 0;
+}
+
 /*
  * Follow the branch starting at the given instruction, and recursively follow
  * any other branches (jumps).  Meanwhile, track the frame pointer state at
@@ -1989,7 +2069,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
 
 				i = insn;
 				save_insn = NULL;
-				func_for_each_insn_continue_reverse(file, func, i) {
+				sym_for_each_insn_continue_reverse(file, func, i) {
 					if (i->save) {
 						save_insn = i;
 						break;
@@ -2050,34 +2130,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
 		switch (insn->type) {
 
 		case INSN_RETURN:
-			if (state.uaccess && !func_uaccess_safe(func)) {
-				WARN_FUNC("return with UACCESS enabled", sec, insn->offset);
-				return 1;
-			}
-
-			if (!state.uaccess && func_uaccess_safe(func)) {
-				WARN_FUNC("return with UACCESS disabled from a UACCESS-safe function", sec, insn->offset);
-				return 1;
-			}
-
-			if (state.df) {
-				WARN_FUNC("return with DF set", sec, insn->offset);
-				return 1;
-			}
-
-			if (func && has_modified_stack_frame(&state)) {
-				WARN_FUNC("return with modified stack frame",
-					  sec, insn->offset);
-				return 1;
-			}
-
-			if (state.bp_scratch) {
-				WARN("%s uses BP as a scratch register",
-				     func->name);
-				return 1;
-			}
-
-			return 0;
+			return validate_return(func, insn, &state);
 
 		case INSN_CALL:
 		case INSN_CALL_DYNAMIC:
@@ -2342,9 +2395,8 @@ static bool ignore_unreachable_insn(struct instruction *insn)
 	return false;
 }
 
-static int validate_functions(struct objtool_file *file)
+static int validate_section(struct objtool_file *file, struct section *sec)
 {
-	struct section *sec;
 	struct symbol *func;
 	struct instruction *insn;
 	struct insn_state state;
@@ -2357,36 +2409,45 @@ static int validate_functions(struct objtool_file *file)
 	       CFI_NUM_REGS * sizeof(struct cfi_reg));
 	state.stack_size = initial_func_cfi.cfa.offset;
 
-	for_each_sec(file, sec) {
-		list_for_each_entry(func, &sec->symbol_list, list) {
-			if (func->type != STT_FUNC)
-				continue;
+	list_for_each_entry(func, &sec->symbol_list, list) {
+		if (func->type != STT_FUNC)
+			continue;
 
-			if (!func->len) {
-				WARN("%s() is missing an ELF size annotation",
-				     func->name);
-				warnings++;
-			}
+		if (!func->len) {
+			WARN("%s() is missing an ELF size annotation",
+			     func->name);
+			warnings++;
+		}
 
-			if (func->pfunc != func || func->alias != func)
-				continue;
+		if (func->pfunc != func || func->alias != func)
+			continue;
 
-			insn = find_insn(file, sec, func->offset);
-			if (!insn || insn->ignore || insn->visited)
-				continue;
+		insn = find_insn(file, sec, func->offset);
+		if (!insn || insn->ignore || insn->visited)
+			continue;
 
-			state.uaccess = func->uaccess_safe;
+		state.uaccess = func->uaccess_safe;
 
-			ret = validate_branch(file, func, insn, state);
-			if (ret && backtrace)
-				BT_FUNC("<=== (func)", insn);
-			warnings += ret;
-		}
+		ret = validate_branch(file, func, insn, state);
+		if (ret && backtrace)
+			BT_FUNC("<=== (func)", insn);
+		warnings += ret;
 	}
 
 	return warnings;
 }
 
+static int validate_functions(struct objtool_file *file)
+{
+	struct section *sec;
+	int warnings = 0;
+
+	for_each_sec(file, sec)
+		warnings += validate_section(file, sec);
+
+	return warnings;
+}
+
 static int validate_reachable_instructions(struct objtool_file *file)
 {
 	struct instruction *insn;
@@ -2405,23 +2466,6 @@ static int validate_reachable_instructions(struct objtool_file *file)
 	return 0;
 }
 
-static void cleanup(struct objtool_file *file)
-{
-	struct instruction *insn, *tmpinsn;
-	struct alternative *alt, *tmpalt;
-
-	list_for_each_entry_safe(insn, tmpinsn, &file->insn_list, list) {
-		list_for_each_entry_safe(alt, tmpalt, &insn->alts, list) {
-			list_del(&alt->list);
-			free(alt);
-		}
-		list_del(&insn->list);
-		hash_del(&insn->hash);
-		free(insn);
-	}
-	elf_close(file->elf);
-}
-
 static struct objtool_file file;
 
 int check(const char *_objname, bool orc)
@@ -2489,10 +2533,14 @@ int check(const char *_objname, bool orc)
 	}
 
 out:
-	cleanup(&file);
+	if (ret < 0) {
+		/*
+		 *  Fatal error.  The binary is corrupt or otherwise broken in
+		 *  some way, or objtool itself is broken.  Fail the kernel
+		 *  build.
+		 */
+		return ret;
+	}
 
-	/* ignore warnings for now until we get all the code cleaned up */
-	if (ret || warnings)
-		return 0;
 	return 0;
 }

tools/objtool/check.h

@@ -50,7 +50,7 @@ struct instruction {
 struct objtool_file {
 	struct elf *elf;
 	struct list_head insn_list;
-	DECLARE_HASHTABLE(insn_hash, 16);
+	DECLARE_HASHTABLE(insn_hash, 20);
 	bool ignore_unreachables, c_file, hints, rodata;
 };
 

tools/objtool/elf.c

@@ -15,17 +15,107 @@
 #include <string.h>
 #include <unistd.h>
 #include <errno.h>
+#include "builtin.h"
 
 #include "elf.h"
 #include "warn.h"
 
 #define MAX_NAME_LEN 128
 
+static inline u32 str_hash(const char *str)
+{
+	return jhash(str, strlen(str), 0);
+}
+
+static void rb_add(struct rb_root *tree, struct rb_node *node,
+		   int (*cmp)(struct rb_node *, const struct rb_node *))
+{
+	struct rb_node **link = &tree->rb_node;
+	struct rb_node *parent = NULL;
+
+	while (*link) {
+		parent = *link;
+		if (cmp(node, parent) < 0)
+			link = &parent->rb_left;
+		else
+			link = &parent->rb_right;
+	}
+
+	rb_link_node(node, parent, link);
+	rb_insert_color(node, tree);
+}
+
+static struct rb_node *rb_find_first(struct rb_root *tree, const void *key,
+			       int (*cmp)(const void *key, const struct rb_node *))
+{
+	struct rb_node *node = tree->rb_node;
+	struct rb_node *match = NULL;
+
+	while (node) {
+		int c = cmp(key, node);
+		if (c <= 0) {
+			if (!c)
+				match = node;
+			node = node->rb_left;
+		} else if (c > 0) {
+			node = node->rb_right;
+		}
+	}
+
+	return match;
+}
+
+static struct rb_node *rb_next_match(struct rb_node *node, const void *key,
+				    int (*cmp)(const void *key, const struct rb_node *))
+{
+	node = rb_next(node);
+	if (node && cmp(key, node))
+		node = NULL;
+	return node;
+}
+
+#define rb_for_each(tree, node, key, cmp) \
+	for ((node) = rb_find_first((tree), (key), (cmp)); \
+	     (node); (node) = rb_next_match((node), (key), (cmp)))
+
+static int symbol_to_offset(struct rb_node *a, const struct rb_node *b)
+{
+	struct symbol *sa = rb_entry(a, struct symbol, node);
+	struct symbol *sb = rb_entry(b, struct symbol, node);
+
+	if (sa->offset < sb->offset)
+		return -1;
+	if (sa->offset > sb->offset)
+		return 1;
+
+	if (sa->len < sb->len)
+		return -1;
+	if (sa->len > sb->len)
+		return 1;
+
+	sa->alias = sb;
+
+	return 0;
+}
+
+static int symbol_by_offset(const void *key, const struct rb_node *node)
+{
+	const struct symbol *s = rb_entry(node, struct symbol, node);
+	const unsigned long *o = key;
+
+	if (*o < s->offset)
+		return -1;
+	if (*o > s->offset + s->len)
+		return 1;
+
+	return 0;
+}
+
 struct section *find_section_by_name(struct elf *elf, const char *name)
 {
 	struct section *sec;
 
-	list_for_each_entry(sec, &elf->sections, list)
+	hash_for_each_possible(elf->section_name_hash, sec, name_hash, str_hash(name))
 		if (!strcmp(sec->name, name))
 			return sec;
 
@@ -37,7 +127,7 @@ static struct section *find_section_by_index(struct elf *elf,
 {
 	struct section *sec;
 
-	list_for_each_entry(sec, &elf->sections, list)
+	hash_for_each_possible(elf->section_hash, sec, hash, idx)
 		if (sec->idx == idx)
 			return sec;
 
@@ -46,88 +136,116 @@ static struct section *find_section_by_index(struct elf *elf,
 
 static struct symbol *find_symbol_by_index(struct elf *elf, unsigned int idx)
 {
-	struct section *sec;
 	struct symbol *sym;
 
-	list_for_each_entry(sec, &elf->sections, list)
-		hash_for_each_possible(sec->symbol_hash, sym, hash, idx)
-			if (sym->idx == idx)
-				return sym;
+	hash_for_each_possible(elf->symbol_hash, sym, hash, idx)
+		if (sym->idx == idx)
+			return sym;
 
 	return NULL;
 }
 
 struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset)
 {
-	struct symbol *sym;
+	struct rb_node *node;
 
-	list_for_each_entry(sym, &sec->symbol_list, list)
-		if (sym->type != STT_SECTION &&
-		    sym->offset == offset)
-			return sym;
+	rb_for_each(&sec->symbol_tree, node, &offset, symbol_by_offset) {
+		struct symbol *s = rb_entry(node, struct symbol, node);
+
+		if (s->offset == offset && s->type != STT_SECTION)
+			return s;
+	}
 
 	return NULL;
 }
 
-struct symbol *find_symbol_by_name(struct elf *elf, const char *name)
+struct symbol *find_func_by_offset(struct section *sec, unsigned long offset)
 {
-	struct section *sec;
-	struct symbol *sym;
+	struct rb_node *node;
 
-	list_for_each_entry(sec, &elf->sections, list)
-		list_for_each_entry(sym, &sec->symbol_list, list)
-			if (!strcmp(sym->name, name))
-				return sym;
+	rb_for_each(&sec->symbol_tree, node, &offset, symbol_by_offset) {
+		struct symbol *s = rb_entry(node, struct symbol, node);
+
+		if (s->offset == offset && s->type == STT_FUNC)
+			return s;
+	}
 
 	return NULL;
 }
 
 struct symbol *find_symbol_containing(struct section *sec, unsigned long offset)
 {
-	struct symbol *sym;
+	struct rb_node *node;
 
-	list_for_each_entry(sym, &sec->symbol_list, list)
-		if (sym->type != STT_SECTION &&
-		    offset >= sym->offset && offset < sym->offset + sym->len)
-			return sym;
+	rb_for_each(&sec->symbol_tree, node, &offset, symbol_by_offset) {
+		struct symbol *s = rb_entry(node, struct symbol, node);
+
+		if (s->type != STT_SECTION)
+			return s;
+	}
 
 	return NULL;
 }
 
-struct rela *find_rela_by_dest_range(struct section *sec, unsigned long offset,
-				     unsigned int len)
+struct symbol *find_func_containing(struct section *sec, unsigned long offset)
 {
-	struct rela *rela;
-	unsigned long o;
+	struct rb_node *node;
 
-	if (!sec->rela)
-		return NULL;
+	rb_for_each(&sec->symbol_tree, node, &offset, symbol_by_offset) {
+		struct symbol *s = rb_entry(node, struct symbol, node);
 
-	for (o = offset; o < offset + len; o++)
-		hash_for_each_possible(sec->rela->rela_hash, rela, hash, o)
-			if (rela->offset == o)
-				return rela;
+		if (s->type == STT_FUNC)
+			return s;
+	}
 
 	return NULL;
 }
 
-struct rela *find_rela_by_dest(struct section *sec, unsigned long offset)
+struct symbol *find_symbol_by_name(struct elf *elf, const char *name)
 {
-	return find_rela_by_dest_range(sec, offset, 1);
+	struct symbol *sym;
+
+	hash_for_each_possible(elf->symbol_name_hash, sym, name_hash, str_hash(name))
+		if (!strcmp(sym->name, name))
+			return sym;
+
+	return NULL;
 }
 
-struct symbol *find_containing_func(struct section *sec, unsigned long offset)
+struct rela *find_rela_by_dest_range(struct elf *elf, struct section *sec,
+				     unsigned long offset, unsigned int len)
 {
-	struct symbol *func;
+	struct rela *rela, *r = NULL;
+	unsigned long o;
+
+	if (!sec->rela)
+		return NULL;
 
-	list_for_each_entry(func, &sec->symbol_list, list)
-		if (func->type == STT_FUNC && offset >= func->offset &&
-		    offset < func->offset + func->len)
-			return func;
+	sec = sec->rela;
+
+	for_offset_range(o, offset, offset + len) {
+		hash_for_each_possible(elf->rela_hash, rela, hash,
+				       sec_offset_hash(sec, o)) {
+			if (rela->sec != sec)
+				continue;
+
+			if (rela->offset >= offset && rela->offset < offset + len) {
+				if (!r || rela->offset < r->offset)
+					r = rela;
+			}
+		}
+		if (r)
+			return r;
+	}
 
 	return NULL;
 }
 
+struct rela *find_rela_by_dest(struct elf *elf, struct section *sec, unsigned long offset)
+{
+	return find_rela_by_dest_range(elf, sec, offset, 1);
+}
+
 static int read_sections(struct elf *elf)
 {
 	Elf_Scn *s = NULL;
@@ -155,10 +273,6 @@ static int read_sections(struct elf *elf)
 
 		INIT_LIST_HEAD(&sec->symbol_list);
 		INIT_LIST_HEAD(&sec->rela_list);
-		hash_init(sec->rela_hash);
-		hash_init(sec->symbol_hash);
-
-		list_add_tail(&sec->list, &elf->sections);
 
 		s = elf_getscn(elf->elf, i);
 		if (!s) {
@@ -193,8 +307,15 @@ static int read_sections(struct elf *elf)
 			}
 		}
 		sec->len = sec->sh.sh_size;
+
+		list_add_tail(&sec->list, &elf->sections);
+		hash_add(elf->section_hash, &sec->hash, sec->idx);
+		hash_add(elf->section_name_hash, &sec->name_hash, str_hash(sec->name));
 	}
 
+	if (stats)
+		printf("nr_sections: %lu\n", (unsigned long)sections_nr);
+
 	/* sanity check, one more call to elf_nextscn() should return NULL */
 	if (elf_nextscn(elf->elf, s)) {
 		WARN("section entry mismatch");
@@ -207,8 +328,9 @@ static int read_sections(struct elf *elf)
 static int read_symbols(struct elf *elf)
 {
 	struct section *symtab, *sec;
-	struct symbol *sym, *pfunc, *alias;
-	struct list_head *entry, *tmp;
+	struct symbol *sym, *pfunc;
+	struct list_head *entry;
+	struct rb_node *pnode;
 	int symbols_nr, i;
 	char *coldstr;
 
@@ -227,7 +349,7 @@ static int read_symbols(struct elf *elf)
 			return -1;
 		}
 		memset(sym, 0, sizeof(*sym));
-		alias = sym;
+		sym->alias = sym;
 
 		sym->idx = i;
 
@@ -265,33 +387,20 @@ static int read_symbols(struct elf *elf)
 		sym->offset = sym->sym.st_value;
 		sym->len = sym->sym.st_size;
 
-		/* sorted insert into a per-section list */
-		entry = &sym->sec->symbol_list;
-		list_for_each_prev(tmp, &sym->sec->symbol_list) {
-			struct symbol *s;
-
-			s = list_entry(tmp, struct symbol, list);
-
-			if (sym->offset > s->offset) {
-				entry = tmp;
-				break;
-			}
-
-			if (sym->offset == s->offset) {
-				if (sym->len && sym->len == s->len && alias == sym)
-					alias = s;
-
-				if (sym->len >= s->len) {
-					entry = tmp;
-					break;
-				}
-			}
-		}
-		sym->alias = alias;
+		rb_add(&sym->sec->symbol_tree, &sym->node, symbol_to_offset);
+		pnode = rb_prev(&sym->node);
+		if (pnode)
+			entry = &rb_entry(pnode, struct symbol, node)->list;
+		else
+			entry = &sym->sec->symbol_list;
 		list_add(&sym->list, entry);
-		hash_add(sym->sec->symbol_hash, &sym->hash, sym->idx);
+		hash_add(elf->symbol_hash, &sym->hash, sym->idx);
+		hash_add(elf->symbol_name_hash, &sym->name_hash, str_hash(sym->name));
 	}
 
+	if (stats)
+		printf("nr_symbols: %lu\n", (unsigned long)symbols_nr);
+
 	/* Create parent/child links for any cold subfunctions */
 	list_for_each_entry(sec, &elf->sections, list) {
 		list_for_each_entry(sym, &sec->symbol_list, list) {
@@ -353,6 +462,7 @@ static int read_relas(struct elf *elf)
 	struct rela *rela;
 	int i;
 	unsigned int symndx;
+	unsigned long nr_rela, max_rela = 0, tot_rela = 0;
 
 	list_for_each_entry(sec, &elf->sections, list) {
 		if (sec->sh.sh_type != SHT_RELA)
@@ -367,6 +477,7 @@ static int read_relas(struct elf *elf)
 
 		sec->base->rela = sec;
 
+		nr_rela = 0;
 		for (i = 0; i < sec->sh.sh_size / sec->sh.sh_entsize; i++) {
 			rela = malloc(sizeof(*rela));
 			if (!rela) {
@@ -393,9 +504,16 @@ static int read_relas(struct elf *elf)
 			}
 
 			list_add_tail(&rela->list, &sec->rela_list);
-			hash_add(sec->rela_hash, &rela->hash, rela->offset);
-
+			hash_add(elf->rela_hash, &rela->hash, rela_hash(rela));
+			nr_rela++;
 		}
+		max_rela = max(max_rela, nr_rela);
+		tot_rela += nr_rela;
+	}
+
+	if (stats) {
+		printf("max_rela: %lu\n", max_rela);
+		printf("tot_rela: %lu\n", tot_rela);
 	}
 
 	return 0;
@@ -415,6 +533,11 @@ struct elf *elf_read(const char *name, int flags)
 	}
 	memset(elf, 0, sizeof(*elf));
 
+	hash_init(elf->symbol_hash);
+	hash_init(elf->symbol_name_hash);
+	hash_init(elf->section_hash);
+	hash_init(elf->section_name_hash);
+	hash_init(elf->rela_hash);
 	INIT_LIST_HEAD(&elf->sections);
 
 	elf->fd = open(name, flags);
@@ -475,10 +598,6 @@ struct section *elf_create_section(struct elf *elf, const char *name,
 
 	INIT_LIST_HEAD(&sec->symbol_list);
 	INIT_LIST_HEAD(&sec->rela_list);
-	hash_init(sec->rela_hash);
-	hash_init(sec->symbol_hash);
-
-	list_add_tail(&sec->list, &elf->sections);
 
 	s = elf_newscn(elf->elf);
 	if (!s) {
@@ -556,6 +675,10 @@ struct section *elf_create_section(struct elf *elf, const char *name,
 	shstrtab->len += strlen(name) + 1;
 	shstrtab->changed = true;
 
+	list_add_tail(&sec->list, &elf->sections);
+	hash_add(elf->section_hash, &sec->hash, sec->idx);
+	hash_add(elf->section_name_hash, &sec->name_hash, str_hash(sec->name));
+
 	return sec;
 }
 

tools/objtool/elf.h

@@ -10,6 +10,8 @@
 #include <gelf.h>
 #include <linux/list.h>
 #include <linux/hashtable.h>
+#include <linux/rbtree.h>
+#include <linux/jhash.h>
 
 #ifdef LIBELF_USE_DEPRECATED
 # define elf_getshdrnum    elf_getshnum
@@ -25,11 +27,12 @@
 
 struct section {
 	struct list_head list;
+	struct hlist_node hash;
+	struct hlist_node name_hash;
 	GElf_Shdr sh;
+	struct rb_root symbol_tree;
 	struct list_head symbol_list;
-	DECLARE_HASHTABLE(symbol_hash, 8);
 	struct list_head rela_list;
-	DECLARE_HASHTABLE(rela_hash, 16);
 	struct section *base, *rela;
 	struct symbol *sym;
 	Elf_Data *data;
@@ -41,7 +44,9 @@ struct section {
 
 struct symbol {
 	struct list_head list;
+	struct rb_node node;
 	struct hlist_node hash;
+	struct hlist_node name_hash;
 	GElf_Sym sym;
 	struct section *sec;
 	char *name;
@@ -71,19 +76,51 @@ struct elf {
 	int fd;
 	char *name;
 	struct list_head sections;
-	DECLARE_HASHTABLE(rela_hash, 16);
+	DECLARE_HASHTABLE(symbol_hash, 20);
+	DECLARE_HASHTABLE(symbol_name_hash, 20);
+	DECLARE_HASHTABLE(section_hash, 16);
+	DECLARE_HASHTABLE(section_name_hash, 16);
+	DECLARE_HASHTABLE(rela_hash, 20);
 };
 
+#define OFFSET_STRIDE_BITS	4
+#define OFFSET_STRIDE		(1UL << OFFSET_STRIDE_BITS)
+#define OFFSET_STRIDE_MASK	(~(OFFSET_STRIDE - 1))
+
+#define for_offset_range(_offset, _start, _end)		\
+	for (_offset = ((_start) & OFFSET_STRIDE_MASK);	\
+	     _offset <= ((_end) & OFFSET_STRIDE_MASK);	\
+	     _offset += OFFSET_STRIDE)
+
+static inline u32 sec_offset_hash(struct section *sec, unsigned long offset)
+{
+	u32 ol, oh, idx = sec->idx;
+
+	offset &= OFFSET_STRIDE_MASK;
+
+	ol = offset;
+	oh = offset >> 32;
+
+	__jhash_mix(ol, oh, idx);
+
+	return ol;
+}
+
+static inline u32 rela_hash(struct rela *rela)
+{
+	return sec_offset_hash(rela->sec, rela->offset);
+}
 
 struct elf *elf_read(const char *name, int flags);
 struct section *find_section_by_name(struct elf *elf, const char *name);
+struct symbol *find_func_by_offset(struct section *sec, unsigned long offset);
 struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset);
 struct symbol *find_symbol_by_name(struct elf *elf, const char *name);
 struct symbol *find_symbol_containing(struct section *sec, unsigned long offset);
-struct rela *find_rela_by_dest(struct section *sec, unsigned long offset);
-struct rela *find_rela_by_dest_range(struct section *sec, unsigned long offset,
-				     unsigned int len);
-struct symbol *find_containing_func(struct section *sec, unsigned long offset);
+struct rela *find_rela_by_dest(struct elf *elf, struct section *sec, unsigned long offset);
+struct rela *find_rela_by_dest_range(struct elf *elf, struct section *sec,
+				     unsigned long offset, unsigned int len);
+struct symbol *find_func_containing(struct section *sec, unsigned long offset);
 struct section *elf_create_section(struct elf *elf, const char *name, size_t
 				   entsize, int nr);
 struct section *elf_create_rela_section(struct elf *elf, struct section *base);

tools/objtool/orc_gen.c

@@ -81,7 +81,7 @@ int create_orc(struct objtool_file *file)
 	return 0;
 }
 
-static int create_orc_entry(struct section *u_sec, struct section *ip_relasec,
+static int create_orc_entry(struct elf *elf, struct section *u_sec, struct section *ip_relasec,
 				unsigned int idx, struct section *insn_sec,
 				unsigned long insn_off, struct orc_entry *o)
 {
@@ -109,9 +109,10 @@ static int create_orc_entry(struct section *u_sec, struct section *ip_relasec,
 	rela->addend = insn_off;
 	rela->type = R_X86_64_PC32;
 	rela->offset = idx * sizeof(int);
+	rela->sec = ip_relasec;
 
 	list_add_tail(&rela->list, &ip_relasec->rela_list);
-	hash_add(ip_relasec->rela_hash, &rela->hash, rela->offset);
+	hash_add(elf->rela_hash, &rela->hash, rela_hash(rela));
 
 	return 0;
 }
@@ -182,7 +183,7 @@ int create_orc_sections(struct objtool_file *file)
 			if (!prev_insn || memcmp(&insn->orc, &prev_insn->orc,
 						 sizeof(struct orc_entry))) {
 
-				if (create_orc_entry(u_sec, ip_relasec, idx,
+				if (create_orc_entry(file->elf, u_sec, ip_relasec, idx,
 						     insn->sec, insn->offset,
 						     &insn->orc))
 					return -1;
@@ -194,7 +195,7 @@ int create_orc_sections(struct objtool_file *file)
 
 		/* section terminator */
 		if (prev_insn) {
-			if (create_orc_entry(u_sec, ip_relasec, idx,
+			if (create_orc_entry(file->elf, u_sec, ip_relasec, idx,
 					     prev_insn->sec,
 					     prev_insn->offset + prev_insn->len,
 					     &empty))

tools/objtool/special.c

@@ -118,7 +118,7 @@ static int get_alt_entry(struct elf *elf, struct special_entry *entry,
 		}
 	}
 
-	orig_rela = find_rela_by_dest(sec, offset + entry->orig);
+	orig_rela = find_rela_by_dest(elf, sec, offset + entry->orig);
 	if (!orig_rela) {
 		WARN_FUNC("can't find orig rela", sec, offset + entry->orig);
 		return -1;
@@ -133,7 +133,7 @@ static int get_alt_entry(struct elf *elf, struct special_entry *entry,
 	alt->orig_off = orig_rela->addend;
 
 	if (!entry->group || alt->new_len) {
-		new_rela = find_rela_by_dest(sec, offset + entry->new);
+		new_rela = find_rela_by_dest(elf, sec, offset + entry->new);
 		if (!new_rela) {
 			WARN_FUNC("can't find new rela",
 				  sec, offset + entry->new);

tools/objtool/warn.h

@@ -21,7 +21,7 @@ static inline char *offstr(struct section *sec, unsigned long offset)
 	char *name, *str;
 	unsigned long name_off;
 
-	func = find_containing_func(sec, offset);
+	func = find_func_containing(sec, offset);
 	if (func) {
 		name = func->name;
 		name_off = offset - func->offset;