Merge tag 'objtool-core-2023-06-27' of git://git.kernel.org/pub/scm/l…

…inux/kernel/git/tip/tip Pull objtool updates from Ingo Molar: "Build footprint & performance improvements: - Reduce memory usage with CONFIG_DEBUG_INFO=y In the worst case of an allyesconfig+CONFIG_DEBUG_INFO=y kernel, DWARF creates almost 200 million relocations, ballooning objtool's peak heap usage to 53GB. These patches reduce that to 25GB. On a distro-type kernel with kernel IBT enabled, they reduce objtool's peak heap usage from 4.2GB to 2.8GB. These changes also improve the runtime significantly. Debuggability improvements: - Add the unwind_debug command-line option, for more extend unwinding debugging output - Limit unreachable warnings to once per function - Add verbose option for disassembling affected functions - Include backtrace in verbose mode - Detect missing __noreturn annotations - Ignore exc_double_fault() __noreturn warnings - Remove superfluous global_noreturns entries - Move noreturn function list to separate file - Add __kunit_abort() to noreturns Unwinder improvements: - Allow stack operations in UNWIND_HINT_UNDEFINED regions - drm/vmwgfx: Add unwind hints around RBP clobber Cleanups: - Move the x86 entry thunk restore code into thunk functions - x86/unwind/orc: Use swap() instead of open coding it - Remove unnecessary/unused variables Fixes for modern stack canary handling" * tag 'objtool-core-2023-06-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (42 commits) x86/orc: Make the is_callthunk() definition depend on CONFIG_BPF_JIT=y objtool: Skip reading DWARF section data objtool: Free insns when done objtool: Get rid of reloc->rel[a] objtool: Shrink elf hash nodes objtool: Shrink reloc->sym_reloc_entry objtool: Get rid of reloc->jump_table_start objtool: Get rid of reloc->addend objtool: Get rid of reloc->type objtool: Get rid of reloc->offset objtool: Get rid of reloc->idx objtool: Get rid of reloc->list objtool: Allocate relocs in advance for new rela sections objtool: Add for_each_reloc() objtool: Don't free memory in elf_close() objtool: Keep GElf_Rel[a] structs synced objtool: Add elf_create_section_pair() objtool: Add mark_sec_changed() objtool: Fix reloc_hash size objtool: Consolidate rel/rela handling ...
nxp-imx · Jun 27, 2023 · 6f61257 · 6f61257
2 parents 4d67518 + 301cf77
commit 6f61257
Show file tree

Hide file tree

Showing 28 changed files with 1,021 additions and 753 deletions.
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
@@ -6598,6 +6598,12 @@
 	unknown_nmi_panic
 			[X86] Cause panic on unknown NMI.
 
+	unwind_debug	[X86-64]
+			Enable unwinder debug output.  This can be
+			useful for debugging certain unwinder error
+			conditions, including corrupt stacks and
+			bad/missing unwinder metadata.
+
 	usbcore.authorized_default=
 			[USB] Default USB device authorization:
 			(default -1 = authorized except for wireless USB,

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
@@ -1605,6 +1605,7 @@ static void add_cpu_to_masks(int cpu)
 }
 
 /* Activate a secondary processor. */
+__no_stack_protector
 void start_secondary(void *unused)
 {
 	unsigned int cpu = raw_smp_processor_id();

diff --git a/arch/x86/entry/thunk_64.S b/arch/x86/entry/thunk_64.S
@@ -26,17 +26,7 @@ SYM_FUNC_START(\name)
 	pushq %r11
 
 	call \func
-	jmp  __thunk_restore
-SYM_FUNC_END(\name)
-	_ASM_NOKPROBE(\name)
-	.endm
-
-	THUNK preempt_schedule_thunk, preempt_schedule
-	THUNK preempt_schedule_notrace_thunk, preempt_schedule_notrace
-	EXPORT_SYMBOL(preempt_schedule_thunk)
-	EXPORT_SYMBOL(preempt_schedule_notrace_thunk)
 
-SYM_CODE_START_LOCAL(__thunk_restore)
 	popq %r11
 	popq %r10
 	popq %r9
@@ -48,5 +38,11 @@ SYM_CODE_START_LOCAL(__thunk_restore)
 	popq %rdi
 	popq %rbp
 	RET
-	_ASM_NOKPROBE(__thunk_restore)
-SYM_CODE_END(__thunk_restore)
+SYM_FUNC_END(\name)
+	_ASM_NOKPROBE(\name)
+	.endm
+
+THUNK preempt_schedule_thunk, preempt_schedule
+THUNK preempt_schedule_notrace_thunk, preempt_schedule_notrace
+EXPORT_SYMBOL(preempt_schedule_thunk)
+EXPORT_SYMBOL(preempt_schedule_notrace_thunk)
diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
@@ -113,7 +113,6 @@ extern void callthunks_patch_builtin_calls(void);
 extern void callthunks_patch_module_calls(struct callthunk_sites *sites,
 					  struct module *mod);
 extern void *callthunks_translate_call_dest(void *dest);
-extern bool is_callthunk(void *addr);
 extern int x86_call_depth_emit_accounting(u8 **pprog, void *func);
 #else
 static __always_inline void callthunks_patch_builtin_calls(void) {}
@@ -124,10 +123,6 @@ static __always_inline void *callthunks_translate_call_dest(void *dest)
 {
 	return dest;
 }
-static __always_inline bool is_callthunk(void *addr)
-{
-	return false;
-}
 static __always_inline int x86_call_depth_emit_accounting(u8 **pprog,
 							  void *func)
 {

diff --git a/arch/x86/include/asm/unwind_hints.h b/arch/x86/include/asm/unwind_hints.h
@@ -76,9 +76,18 @@
 
 #else
 
+#define UNWIND_HINT_UNDEFINED \
+	UNWIND_HINT(UNWIND_HINT_TYPE_UNDEFINED, 0, 0, 0)
+
 #define UNWIND_HINT_FUNC \
 	UNWIND_HINT(UNWIND_HINT_TYPE_FUNC, ORC_REG_SP, 8, 0)
 
+#define UNWIND_HINT_SAVE \
+	UNWIND_HINT(UNWIND_HINT_TYPE_SAVE, 0, 0, 0)
+
+#define UNWIND_HINT_RESTORE \
+	UNWIND_HINT(UNWIND_HINT_TYPE_RESTORE, 0, 0, 0)
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_X86_UNWIND_HINTS_H */
diff --git a/arch/x86/kernel/callthunks.c b/arch/x86/kernel/callthunks.c
@@ -293,7 +293,8 @@ void *callthunks_translate_call_dest(void *dest)
 	return target ? : dest;
 }
 
-bool is_callthunk(void *addr)
+#ifdef CONFIG_BPF_JIT
+static bool is_callthunk(void *addr)
 {
 	unsigned int tmpl_size = SKL_TMPL_SIZE;
 	void *tmpl = skl_call_thunk_template;
@@ -306,7 +307,6 @@ bool is_callthunk(void *addr)
 	return !bcmp((void *)(dest - tmpl_size), tmpl, tmpl_size);
 }
 
-#ifdef CONFIG_BPF_JIT
 int x86_call_depth_emit_accounting(u8 **pprog, void *func)
 {
 	unsigned int tmpl_size = SKL_TMPL_SIZE;

diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c
@@ -16,8 +16,14 @@ ORC_HEADER;
 
 #define orc_warn_current(args...)					\
 ({									\
-	if (state->task == current && !state->error)			\
+	static bool dumped_before;					\
+	if (state->task == current && !state->error) {			\
 		orc_warn(args);						\
+		if (unwind_debug && !dumped_before) {			\
+			dumped_before = true;				\
+			unwind_dump(state);				\
+		}							\
+	}								\
 })
 
 extern int __start_orc_unwind_ip[];
@@ -26,8 +32,49 @@ extern struct orc_entry __start_orc_unwind[];
 extern struct orc_entry __stop_orc_unwind[];
 
 static bool orc_init __ro_after_init;
+static bool unwind_debug __ro_after_init;
 static unsigned int lookup_num_blocks __ro_after_init;
 
+static int __init unwind_debug_cmdline(char *str)
+{
+	unwind_debug = true;
+
+	return 0;
+}
+early_param("unwind_debug", unwind_debug_cmdline);
+
+static void unwind_dump(struct unwind_state *state)
+{
+	static bool dumped_before;
+	unsigned long word, *sp;
+	struct stack_info stack_info = {0};
+	unsigned long visit_mask = 0;
+
+	if (dumped_before)
+		return;
+
+	dumped_before = true;
+
+	printk_deferred("unwind stack type:%d next_sp:%p mask:0x%lx graph_idx:%d\n",
+			state->stack_info.type, state->stack_info.next_sp,
+			state->stack_mask, state->graph_idx);
+
+	for (sp = __builtin_frame_address(0); sp;
+	     sp = PTR_ALIGN(stack_info.next_sp, sizeof(long))) {
+		if (get_stack_info(sp, state->task, &stack_info, &visit_mask))
+			break;
+
+		for (; sp < stack_info.end; sp++) {
+
+			word = READ_ONCE_NOCHECK(*sp);
+
+			printk_deferred("%0*lx: %0*lx (%pB)\n", BITS_PER_LONG/4,
+					(unsigned long)sp, BITS_PER_LONG/4,
+					word, (void *)word);
+		}
+	}
+}
+
 static inline unsigned long orc_ip(const int *ip)
 {
 	return (unsigned long)ip + *ip;
@@ -139,21 +186,6 @@ static struct orc_entry null_orc_entry = {
 	.type = ORC_TYPE_CALL
 };
 
-#ifdef CONFIG_CALL_THUNKS
-static struct orc_entry *orc_callthunk_find(unsigned long ip)
-{
-	if (!is_callthunk((void *)ip))
-		return NULL;
-
-	return &null_orc_entry;
-}
-#else
-static struct orc_entry *orc_callthunk_find(unsigned long ip)
-{
-	return NULL;
-}
-#endif
-
 /* Fake frame pointer entry -- used as a fallback for generated code */
 static struct orc_entry orc_fp_entry = {
 	.type		= ORC_TYPE_CALL,
@@ -206,11 +238,7 @@ static struct orc_entry *orc_find(unsigned long ip)
 	if (orc)
 		return orc;
 
-	orc =  orc_ftrace_find(ip);
-	if (orc)
-		return orc;
-
-	return orc_callthunk_find(ip);
+	return orc_ftrace_find(ip);
 }
 
 #ifdef CONFIG_MODULES
@@ -222,7 +250,6 @@ static struct orc_entry *cur_orc_table = __start_orc_unwind;
 static void orc_sort_swap(void *_a, void *_b, int size)
 {
 	struct orc_entry *orc_a, *orc_b;
-	struct orc_entry orc_tmp;
 	int *a = _a, *b = _b, tmp;
 	int delta = _b - _a;
 
@@ -234,9 +261,7 @@ static void orc_sort_swap(void *_a, void *_b, int size)
 	/* Swap the corresponding .orc_unwind entries: */
 	orc_a = cur_orc_table + (a - cur_orc_ip_table);
 	orc_b = cur_orc_table + (b - cur_orc_ip_table);
-	orc_tmp = *orc_a;
-	*orc_a = *orc_b;
-	*orc_b = orc_tmp;
+	swap(*orc_a, *orc_b);
 }
 
 static int orc_sort_cmp(const void *_a, const void *_b)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_msg_x86.h b/drivers/gpu/drm/vmwgfx/vmwgfx_msg_x86.h
@@ -105,10 +105,14 @@
                         flags, magic, bp,		\
                         eax, ebx, ecx, edx, si, di)	\
 ({							\
-        asm volatile ("push %%rbp;"			\
+        asm volatile (					\
+		UNWIND_HINT_SAVE			\
+		"push %%rbp;"				\
+		UNWIND_HINT_UNDEFINED			\
                 "mov %12, %%rbp;"			\
                 VMWARE_HYPERCALL_HB_OUT			\
-                "pop %%rbp;" :				\
+                "pop %%rbp;"				\
+		UNWIND_HINT_RESTORE :			\
                 "=a"(eax),				\
                 "=b"(ebx),				\
                 "=c"(ecx),				\
@@ -130,10 +134,14 @@
                        flags, magic, bp,		\
                        eax, ebx, ecx, edx, si, di)	\
 ({							\
-        asm volatile ("push %%rbp;"			\
+        asm volatile (					\
+		UNWIND_HINT_SAVE			\
+		"push %%rbp;"				\
+		UNWIND_HINT_UNDEFINED			\
                 "mov %12, %%rbp;"			\
                 VMWARE_HYPERCALL_HB_IN			\
-                "pop %%rbp" :				\
+                "pop %%rbp;"				\
+		UNWIND_HINT_RESTORE :			\
                 "=a"(eax),				\
                 "=b"(ebx),				\
                 "=c"(ecx),				\

diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c
@@ -487,6 +487,7 @@ static void lkdtm_UNSET_SMEP(void)
 	 * the cr4 writing instruction.
 	 */
 	insn = (unsigned char *)native_write_cr4;
+	OPTIMIZER_HIDE_VAR(insn);
 	for (i = 0; i < MOV_CR4_DEPTH; i++) {
 		/* mov %rdi, %cr4 */
 		if (insn[i] == 0x0f && insn[i+1] == 0x22 && insn[i+2] == 0xe7)

diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h
@@ -255,6 +255,18 @@
  */
 #define __noreturn                      __attribute__((__noreturn__))
 
+/*
+ * Optional: only supported since GCC >= 11.1, clang >= 7.0.
+ *
+ *   gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-no_005fstack_005fprotector-function-attribute
+ *   clang: https://clang.llvm.org/docs/AttributeReference.html#no-stack-protector-safebuffers
+ */
+#if __has_attribute(__no_stack_protector__)
+# define __no_stack_protector		__attribute__((__no_stack_protector__))
+#else
+# define __no_stack_protector
+#endif
+
 /*
  * Optional: not supported by gcc.
  *

diff --git a/init/main.c b/init/main.c
@@ -873,7 +873,8 @@ static void __init print_unknown_bootoptions(void)
 	memblock_free(unknown_options, len);
 }
 
-asmlinkage __visible void __init __no_sanitize_address __noreturn start_kernel(void)
+asmlinkage __visible __init __no_sanitize_address __noreturn __no_stack_protector
+void start_kernel(void)
 {
 	char *command_line;
 	char *after_dashes;
@@ -1073,7 +1074,13 @@ asmlinkage __visible void __init __no_sanitize_address __noreturn start_kernel(v
 	/* Do the rest non-__init'ed, we're now alive */
 	arch_call_rest_init();
 
+	/*
+	 * Avoid stack canaries in callers of boot_init_stack_canary for gcc-10
+	 * and older.
+	 */
+#if !__has_attribute(__no_stack_protector__)
 	prevent_tail_call_optimization();
+#endif
 }
 
 /* Call all constructor functions linked into the kernel. */

diff --git a/tools/lib/subcmd/parse-options.h b/tools/lib/subcmd/parse-options.h
@@ -6,10 +6,6 @@
 #include <stdbool.h>
 #include <stdint.h>
 
-#ifndef NORETURN
-#define NORETURN __attribute__((__noreturn__))
-#endif
-
 enum parse_opt_type {
 	/* special types */
 	OPTION_END,
@@ -183,9 +179,9 @@ extern int parse_options_subcommand(int argc, const char **argv,
 				const char *const subcommands[],
 				const char *usagestr[], int flags);
 
-extern NORETURN void usage_with_options(const char * const *usagestr,
+extern __noreturn void usage_with_options(const char * const *usagestr,
                                         const struct option *options);
-extern NORETURN __attribute__((format(printf,3,4)))
+extern __noreturn __attribute__((format(printf,3,4)))
 void usage_with_options_msg(const char * const *usagestr,
 			    const struct option *options,
 			    const char *fmt, ...);

diff --git a/tools/lib/subcmd/subcmd-util.h b/tools/lib/subcmd/subcmd-util.h
@@ -5,8 +5,7 @@
 #include <stdarg.h>
 #include <stdlib.h>
 #include <stdio.h>
-
-#define NORETURN __attribute__((__noreturn__))
+#include <linux/compiler.h>
 
 static inline void report(const char *prefix, const char *err, va_list params)
 {
@@ -15,7 +14,7 @@ static inline void report(const char *prefix, const char *err, va_list params)
 	fprintf(stderr, " %s%s\n", prefix, msg);
 }
 
-static NORETURN inline void die(const char *err, ...)
+static __noreturn inline void die(const char *err, ...)
 {
 	va_list params;
 

diff --git a/tools/objtool/Documentation/objtool.txt b/tools/objtool/Documentation/objtool.txt
@@ -244,6 +244,11 @@ To achieve the validation, objtool enforces the following rules:
 Objtool warnings
 ----------------
 
+NOTE: When requesting help with an objtool warning, please recreate with
+OBJTOOL_VERBOSE=1 (e.g., "make OBJTOOL_VERBOSE=1") and send the full
+output, including any disassembly or backtrace below the warning, to the
+objtool maintainers.
+
 For asm files, if you're getting an error which doesn't make sense,
 first make sure that the affected code follows the above rules.
 
@@ -298,6 +303,11 @@ the objtool maintainers.
    If it's not actually in a callable function (e.g. kernel entry code),
    change ENDPROC to END.
 
+3. file.o: warning: objtool: foo+0x48c: bar() is missing a __noreturn annotation
+
+   The call from foo() to bar() doesn't return, but bar() is missing the
+   __noreturn annotation.  NOTE: In addition to annotating the function
+   with __noreturn, please also add it to tools/objtool/noreturns.h.
 
 4. file.o: warning: objtool: func(): can't find starting instruction
    or

diff --git a/tools/objtool/arch/powerpc/include/arch/elf.h b/tools/objtool/arch/powerpc/include/arch/elf.h
@@ -1,10 +1,13 @@
 /* SPDX-License-Identifier: GPL-2.0-or-later */
-
 #ifndef _OBJTOOL_ARCH_ELF
 #define _OBJTOOL_ARCH_ELF
 
-#define R_NONE R_PPC_NONE
-#define R_ABS64 R_PPC64_ADDR64
-#define R_ABS32 R_PPC_ADDR32
+#define R_NONE		R_PPC_NONE
+#define R_ABS64		R_PPC64_ADDR64
+#define R_ABS32		R_PPC_ADDR32
+#define R_DATA32	R_PPC_REL32
+#define R_DATA64	R_PPC64_REL64
+#define R_TEXT32	R_PPC_REL32
+#define R_TEXT64	R_PPC64_REL32
 
 #endif /* _OBJTOOL_ARCH_ELF */