From fb27e70f6e408dee5d22b083e7a38a59e6118253 Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Wed, 22 Mar 2023 19:11:45 +0100 Subject: modpost: Fix processing of CRCs on 32-bit build machines modpost now reads CRCs from .*.cmd files, parsing them using strtol(). This is inconsistent with its parsing of Module.symvers and with their definition as *unsigned* 32-bit values. strtol() clamps values to [LONG_MIN, LONG_MAX], and when building on a 32-bit system this changes all CRCs >= 0x80000000 to be 0x7fffffff. Change extract_crcs_for_object() to use strtoul() instead. Cc: stable@vger.kernel.org Fixes: f292d875d0dc ("modpost: extract symbol versions from *.cmd files") Signed-off-by: Ben Hutchings Signed-off-by: Masahiro Yamada --- scripts/mod/modpost.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'scripts/mod/modpost.c') diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index efff8078e395..9466b6a2abae 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -1733,7 +1733,7 @@ static void extract_crcs_for_object(const char *object, struct module *mod) if (!isdigit(*p)) continue; /* skip this line */ - crc = strtol(p, &p, 0); + crc = strtoul(p, &p, 0); if (*p != '\n') continue; /* skip this line */ -- cgit From 87e5b1e8f257023ac5c4d2b8f07716a7f3dcc8ea Mon Sep 17 00:00:00 2001 From: Tiezhu Yang Date: Fri, 31 Mar 2023 17:15:51 +0800 Subject: module: Sync code of is_arm_mapping_symbol() After commit 2e3a10a1551d ("ARM: avoid ARM binutils leaking ELF local symbols") and commit d6b732666a1b ("modpost: fix undefined behavior of is_arm_mapping_symbol()"), many differences of is_arm_mapping_symbol() exist in kernel/module/kallsyms.c and scripts/mod/modpost.c, just sync the code to keep consistent. Signed-off-by: Tiezhu Yang Signed-off-by: Luis Chamberlain --- kernel/module/kallsyms.c | 5 +++-- scripts/mod/modpost.c | 2 ++ 2 files changed, 5 insertions(+), 2 deletions(-) (limited to 'scripts/mod/modpost.c') diff --git a/kernel/module/kallsyms.c b/kernel/module/kallsyms.c index 3320586584f1..a9045fe55bcd 100644 --- a/kernel/module/kallsyms.c +++ b/kernel/module/kallsyms.c @@ -251,8 +251,9 @@ static inline int is_arm_mapping_symbol(const char *str) { if (str[0] == '.' && str[1] == 'L') return true; - return str[0] == '$' && strchr("axtd", str[1]) && - (str[2] == '\0' || str[2] == '.'); + return str[0] == '$' && + (str[1] == 'a' || str[1] == 'd' || str[1] == 't' || str[1] == 'x') + && (str[2] == '\0' || str[2] == '.'); } static const char *kallsyms_symbol_name(struct mod_kallsyms *kallsyms, unsigned int symnum) diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index efff8078e395..79a27cc5f0b1 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -1114,6 +1114,8 @@ static int secref_whitelist(const struct sectioncheck *mismatch, static inline int is_arm_mapping_symbol(const char *str) { + if (str[0] == '.' && str[1] == 'L') + return true; return str[0] == '$' && (str[1] == 'a' || str[1] == 'd' || str[1] == 't' || str[1] == 'x') && (str[2] == '\0' || str[2] == '.'); -- cgit From 987d2e0aaa55de40938435be760aa96428470fd6 Mon Sep 17 00:00:00 2001 From: Tiezhu Yang Date: Fri, 31 Mar 2023 17:15:52 +0800 Subject: module: Move is_arm_mapping_symbol() to module_symbol.h In order to avoid duplicated code, move is_arm_mapping_symbol() to include/linux/module_symbol.h, then remove is_arm_mapping_symbol() in the other places. Signed-off-by: Tiezhu Yang Signed-off-by: Luis Chamberlain --- include/linux/module_symbol.h | 15 +++++++++++++++ kernel/module/kallsyms.c | 14 +------------- scripts/mod/modpost.c | 10 +--------- 3 files changed, 17 insertions(+), 22 deletions(-) create mode 100644 include/linux/module_symbol.h (limited to 'scripts/mod/modpost.c') diff --git a/include/linux/module_symbol.h b/include/linux/module_symbol.h new file mode 100644 index 000000000000..9fa4173d0197 --- /dev/null +++ b/include/linux/module_symbol.h @@ -0,0 +1,15 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef _LINUX_MODULE_SYMBOL_H +#define _LINUX_MODULE_SYMBOL_H + +/* This ignores the intensely annoying "mapping symbols" found in ELF files. */ +static inline int is_arm_mapping_symbol(const char *str) +{ + if (str[0] == '.' && str[1] == 'L') + return true; + return str[0] == '$' && + (str[1] == 'a' || str[1] == 'd' || str[1] == 't' || str[1] == 'x') + && (str[2] == '\0' || str[2] == '.'); +} + +#endif /* _LINUX_MODULE_SYMBOL_H */ diff --git a/kernel/module/kallsyms.c b/kernel/module/kallsyms.c index a9045fe55bcd..5de3207f18af 100644 --- a/kernel/module/kallsyms.c +++ b/kernel/module/kallsyms.c @@ -6,6 +6,7 @@ */ #include +#include #include #include #include @@ -243,19 +244,6 @@ void init_build_id(struct module *mod, const struct load_info *info) } #endif -/* - * This ignores the intensely annoying "mapping symbols" found - * in ARM ELF files: $a, $t and $d. - */ -static inline int is_arm_mapping_symbol(const char *str) -{ - if (str[0] == '.' && str[1] == 'L') - return true; - return str[0] == '$' && - (str[1] == 'a' || str[1] == 'd' || str[1] == 't' || str[1] == 'x') - && (str[2] == '\0' || str[2] == '.'); -} - static const char *kallsyms_symbol_name(struct mod_kallsyms *kallsyms, unsigned int symnum) { return kallsyms->strtab + kallsyms->symtab[symnum].st_name; diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 79a27cc5f0b1..7241db81ffde 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -22,6 +22,7 @@ #include #include "modpost.h" #include "../../include/linux/license.h" +#include "../../include/linux/module_symbol.h" /* Are we using CONFIG_MODVERSIONS? */ static bool modversions; @@ -1112,15 +1113,6 @@ static int secref_whitelist(const struct sectioncheck *mismatch, return 1; } -static inline int is_arm_mapping_symbol(const char *str) -{ - if (str[0] == '.' && str[1] == 'L') - return true; - return str[0] == '$' && - (str[1] == 'a' || str[1] == 'd' || str[1] == 't' || str[1] == 'x') - && (str[2] == '\0' || str[2] == '.'); -} - /* * If there's no name there, ignore it; likewise, ignore it if it's * one of the magic symbols emitted used by current ARM tools. -- cgit From 0a3bf86092c38f7b72c56c6901c78dd302411307 Mon Sep 17 00:00:00 2001 From: Tiezhu Yang Date: Fri, 31 Mar 2023 17:15:53 +0800 Subject: module: Ignore L0 and rename is_arm_mapping_symbol() The L0 symbol is generated when build module on LoongArch, ignore it in modpost and when looking at module symbols, otherwise we can not see the expected call trace. Now is_arm_mapping_symbol() is not only for ARM, in order to reflect the reality, rename is_arm_mapping_symbol() to is_mapping_symbol(). This is related with commit c17a2538704f ("mksysmap: Fix the mismatch of 'L0' symbols in System.map"). (1) Simple test case [loongson@linux hello]$ cat hello.c #include #include #include static void test_func(void) { pr_info("This is a test\n"); dump_stack(); } static int __init hello_init(void) { pr_warn("Hello, world\n"); test_func(); return 0; } static void __exit hello_exit(void) { pr_warn("Goodbye\n"); } module_init(hello_init); module_exit(hello_exit); MODULE_LICENSE("GPL"); [loongson@linux hello]$ cat Makefile obj-m:=hello.o ccflags-y += -g -Og all: make -C /lib/modules/$(shell uname -r)/build/ M=$(PWD) modules clean: make -C /lib/modules/$(shell uname -r)/build/ M=$(PWD) clean (2) Test environment system: LoongArch CLFS 5.5 https://github.com/sunhaiyong1978/CLFS-for-LoongArch/releases/tag/5.0 It needs to update grub to avoid booting error "invalid magic number". kernel: 6.3-rc1 with loongson3_defconfig + CONFIG_DYNAMIC_FTRACE=y (3) Test result Without this patch: [root@linux hello]# insmod hello.ko [root@linux hello]# dmesg ... Hello, world This is a test ... Call Trace: [<9000000000223728>] show_stack+0x68/0x18c [<90000000013374cc>] dump_stack_lvl+0x60/0x88 [] L0\x01+0x20/0x2c [hello] [] L0\x01+0x20/0x30 [hello] [<900000000022097c>] do_one_initcall+0x88/0x288 [<90000000002df890>] do_init_module+0x54/0x200 [<90000000002e1e18>] __do_sys_finit_module+0xc4/0x114 [<90000000013382e8>] do_syscall+0x7c/0x94 [<9000000000221e3c>] handle_syscall+0xbc/0x158 With this patch: [root@linux hello]# insmod hello.ko [root@linux hello]# dmesg ... Hello, world This is a test ... Call Trace: [<9000000000223728>] show_stack+0x68/0x18c [<90000000013374cc>] dump_stack_lvl+0x60/0x88 [] test_func+0x28/0x34 [hello] [] hello_init+0x28/0x38 [hello] [<900000000022097c>] do_one_initcall+0x88/0x288 [<90000000002df890>] do_init_module+0x54/0x200 [<90000000002e1e18>] __do_sys_finit_module+0xc4/0x114 [<90000000013382e8>] do_syscall+0x7c/0x94 [<9000000000221e3c>] handle_syscall+0xbc/0x158 Signed-off-by: Tiezhu Yang Tested-by: Youling Tang # for LoongArch Signed-off-by: Luis Chamberlain --- include/linux/module_symbol.h | 4 +++- kernel/module/kallsyms.c | 2 +- scripts/mod/modpost.c | 4 ++-- 3 files changed, 6 insertions(+), 4 deletions(-) (limited to 'scripts/mod/modpost.c') diff --git a/include/linux/module_symbol.h b/include/linux/module_symbol.h index 9fa4173d0197..7ace7ba30203 100644 --- a/include/linux/module_symbol.h +++ b/include/linux/module_symbol.h @@ -3,10 +3,12 @@ #define _LINUX_MODULE_SYMBOL_H /* This ignores the intensely annoying "mapping symbols" found in ELF files. */ -static inline int is_arm_mapping_symbol(const char *str) +static inline int is_mapping_symbol(const char *str) { if (str[0] == '.' && str[1] == 'L') return true; + if (str[0] == 'L' && str[1] == '0') + return true; return str[0] == '$' && (str[1] == 'a' || str[1] == 'd' || str[1] == 't' || str[1] == 'x') && (str[2] == '\0' || str[2] == '.'); diff --git a/kernel/module/kallsyms.c b/kernel/module/kallsyms.c index 5de3207f18af..d8e426a9a0cd 100644 --- a/kernel/module/kallsyms.c +++ b/kernel/module/kallsyms.c @@ -289,7 +289,7 @@ static const char *find_kallsyms_symbol(struct module *mod, * and inserted at a whim. */ if (*kallsyms_symbol_name(kallsyms, i) == '\0' || - is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms, i))) + is_mapping_symbol(kallsyms_symbol_name(kallsyms, i))) continue; if (thisval <= addr && thisval > bestval) { diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 7241db81ffde..5cddf7623945 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -1115,7 +1115,7 @@ static int secref_whitelist(const struct sectioncheck *mismatch, /* * If there's no name there, ignore it; likewise, ignore it if it's - * one of the magic symbols emitted used by current ARM tools. + * one of the magic symbols emitted used by current tools. * * Otherwise if find_symbols_between() returns those symbols, they'll * fail the whitelist tests and cause lots of false alarms ... fixable @@ -1128,7 +1128,7 @@ static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) if (!name || !strlen(name)) return 0; - return !is_arm_mapping_symbol(name); + return !is_mapping_symbol(name); } /** -- cgit From b9f174c811e3ae4ae8959dc57e6adb9990e913f4 Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Tue, 13 Jun 2023 14:14:56 -0700 Subject: x86/unwind/orc: Add ELF section with ORC version identifier Commits ffb1b4a41016 ("x86/unwind/orc: Add 'signal' field to ORC metadata") and fb799447ae29 ("x86,objtool: Split UNWIND_HINT_EMPTY in two") changed the ORC format. Although ORC is internal to the kernel, it's the only way for external tools to get reliable kernel stack traces on x86-64. In particular, the drgn debugger [1] uses ORC for stack unwinding, and these format changes broke it [2]. As the drgn maintainer, I don't care how often or how much the kernel changes the ORC format as long as I have a way to detect the change. It suffices to store a version identifier in the vmlinux and kernel module ELF files (to use when parsing ORC sections from ELF), and in kernel memory (to use when parsing ORC from a core dump+symbol table). Rather than hard-coding a version number that needs to be manually bumped, Peterz suggested hashing the definitions from orc_types.h. If there is a format change that isn't caught by this, the hashing script can be updated. This patch adds an .orc_header allocated ELF section containing the 20-byte hash to vmlinux and kernel modules, along with the corresponding __start_orc_header and __stop_orc_header symbols in vmlinux. 1: https://github.com/osandov/drgn 2: https://github.com/osandov/drgn/issues/303 Fixes: ffb1b4a41016 ("x86/unwind/orc: Add 'signal' field to ORC metadata") Fixes: fb799447ae29 ("x86,objtool: Split UNWIND_HINT_EMPTY in two") Signed-off-by: Omar Sandoval Signed-off-by: Peter Zijlstra (Intel) Acked-by: Josh Poimboeuf Link: https://lkml.kernel.org/r/aef9c8dc43915b886a8c48509a12ec1b006ca1ca.1686690801.git.osandov@osandov.com --- arch/x86/Makefile | 12 ++++++++++++ arch/x86/include/asm/Kbuild | 1 + arch/x86/include/asm/orc_header.h | 19 +++++++++++++++++++ arch/x86/kernel/unwind_orc.c | 3 +++ include/asm-generic/vmlinux.lds.h | 3 +++ scripts/mod/modpost.c | 5 +++++ scripts/orc_hash.sh | 16 ++++++++++++++++ 7 files changed, 59 insertions(+) create mode 100644 arch/x86/include/asm/orc_header.h create mode 100644 scripts/orc_hash.sh (limited to 'scripts/mod/modpost.c') diff --git a/arch/x86/Makefile b/arch/x86/Makefile index b39975977c03..fdc2e3abd615 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -305,6 +305,18 @@ ifeq ($(RETPOLINE_CFLAGS),) endif endif +ifdef CONFIG_UNWINDER_ORC +orc_hash_h := arch/$(SRCARCH)/include/generated/asm/orc_hash.h +orc_hash_sh := $(srctree)/scripts/orc_hash.sh +targets += $(orc_hash_h) +quiet_cmd_orc_hash = GEN $@ + cmd_orc_hash = mkdir -p $(dir $@); \ + $(CONFIG_SHELL) $(orc_hash_sh) < $< > $@ +$(orc_hash_h): $(srctree)/arch/x86/include/asm/orc_types.h $(orc_hash_sh) FORCE + $(call if_changed,orc_hash) +archprepare: $(orc_hash_h) +endif + archclean: $(Q)rm -rf $(objtree)/arch/i386 $(Q)rm -rf $(objtree)/arch/x86_64 diff --git a/arch/x86/include/asm/Kbuild b/arch/x86/include/asm/Kbuild index 1e51650b79d7..4f1ce5fc4e19 100644 --- a/arch/x86/include/asm/Kbuild +++ b/arch/x86/include/asm/Kbuild @@ -1,6 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 +generated-y += orc_hash.h generated-y += syscalls_32.h generated-y += syscalls_64.h generated-y += syscalls_x32.h diff --git a/arch/x86/include/asm/orc_header.h b/arch/x86/include/asm/orc_header.h new file mode 100644 index 000000000000..07bacf3e160e --- /dev/null +++ b/arch/x86/include/asm/orc_header.h @@ -0,0 +1,19 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* Copyright (c) Meta Platforms, Inc. and affiliates. */ + +#ifndef _ORC_HEADER_H +#define _ORC_HEADER_H + +#include +#include +#include + +/* + * The header is currently a 20-byte hash of the ORC entry definition; see + * scripts/orc_hash.sh. + */ +#define ORC_HEADER \ + __used __section(".orc_header") __aligned(4) \ + static const u8 orc_header[] = { ORC_HASH } + +#endif /* _ORC_HEADER_H */ diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c index 3ac50b7298d1..4d8e518365f4 100644 --- a/arch/x86/kernel/unwind_orc.c +++ b/arch/x86/kernel/unwind_orc.c @@ -7,6 +7,9 @@ #include #include #include +#include + +ORC_HEADER; #define orc_warn(fmt, ...) \ printk_deferred_once(KERN_WARNING "WARNING: " fmt, ##__VA_ARGS__) diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index cebdf1ca415d..da9e5629ea43 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -839,6 +839,9 @@ #ifdef CONFIG_UNWINDER_ORC #define ORC_UNWIND_TABLE \ + .orc_header : AT(ADDR(.orc_header) - LOAD_OFFSET) { \ + BOUNDED_SECTION_BY(.orc_header, _orc_header) \ + } \ . = ALIGN(4); \ .orc_unwind_ip : AT(ADDR(.orc_unwind_ip) - LOAD_OFFSET) { \ BOUNDED_SECTION_BY(.orc_unwind_ip, _orc_unwind_ip) \ diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index d4531d09984d..c12150f96b88 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -1979,6 +1979,11 @@ static void add_header(struct buffer *b, struct module *mod) buf_printf(b, "#include \n"); buf_printf(b, "#include \n"); buf_printf(b, "\n"); + buf_printf(b, "#ifdef CONFIG_UNWINDER_ORC\n"); + buf_printf(b, "#include \n"); + buf_printf(b, "ORC_HEADER;\n"); + buf_printf(b, "#endif\n"); + buf_printf(b, "\n"); buf_printf(b, "BUILD_SALT;\n"); buf_printf(b, "BUILD_LTO_INFO;\n"); buf_printf(b, "\n"); diff --git a/scripts/orc_hash.sh b/scripts/orc_hash.sh new file mode 100644 index 000000000000..466611aa0053 --- /dev/null +++ b/scripts/orc_hash.sh @@ -0,0 +1,16 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0-or-later +# Copyright (c) Meta Platforms, Inc. and affiliates. + +set -e + +printf '%s' '#define ORC_HASH ' + +awk ' +/^#define ORC_(REG|TYPE)_/ { print } +/^struct orc_entry {$/ { p=1 } +p { print } +/^}/ { p=0 }' | + sha1sum | + cut -d " " -f 1 | + sed 's/\([0-9a-f]\{2\}\)/0x\1,/g' -- cgit