[v3] kallsyms: enhance %pS/s/b printing when KALLSYSMS is disabled

Message ID	20220315155100.516107-1-maninder1.s@samsung.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-modules-owner@kernel.org> From: Maninder Singh <maninder1.s@samsung.com> To: mcgrof@kernel.org, pmladek@suse.com, rostedt@goodmis.org, senozhatsky@chromium.org, andriy.shevchenko@linux.intel.com, linux@rasmusvillemoes.dk, akpm@linux-foundation.org, wangkefeng.wang@huawei.com Cc: v.narang@samsung.com, swboyd@chromium.org, ojeda@kernel.org, linux-kernel@vger.kernel.org, linux-modules@vger.kernel.org, avimalin@gmail.com, atomlin@redhat.com, Maninder Singh <maninder1.s@samsung.com> Subject: [PATCH v3] kallsyms: enhance %pS/s/b printing when KALLSYSMS is disabled Date: Tue, 15 Mar 2022 21:21:00 +0530 Message-Id: <20220315155100.516107-1-maninder1.s@samsung.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="utf-8" CMS-TYPE: 105P References: <CGME20220315155109epcas5p249963f50d68ee368edb569b1a9e7d63c@epcas5p2.samsung.com> Precedence: bulk
Series	[v3] kallsyms: enhance %pS/s/b printing when KALLSYSMS is disabled \| expand [v3] kallsyms: enhance %pS/s/b printing when KALLSYSMS is disabled

diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h index e5ad6e31697d..c24fa627ab6e 100644 --- a/include/linux/kallsyms.h +++ b/include/linux/kallsyms.h @@ -89,6 +89,8 @@ extern int sprint_symbol_build_id(char *buffer, unsigned long address); extern int sprint_symbol_no_offset(char *buffer, unsigned long address); extern int sprint_backtrace(char *buffer, unsigned long address); extern int sprint_backtrace_build_id(char *buffer, unsigned long address); +extern int sprint_kallsym_common(char *buffer, unsigned long address, int build_id, + int backtrace, int symbol); int lookup_symbol_name(unsigned long addr, char *symname); int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name); diff --git a/include/linux/module.h b/include/linux/module.h index 1e135fd5c076..b154fa822f77 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -678,6 +678,20 @@ static inline bool is_livepatch_module(struct module *mod) bool is_module_sig_enforced(void); void set_module_sig_enforced(void); +static inline int fill_name_build_id(char *buffer, char *modname, + int add_buildid, const unsigned char *buildid, + int len) +{ + len += sprintf(buffer + len, " [%s", modname); +#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID) + if (add_buildid && buildid) { + /* build ID should match length of sprintf */ + static_assert(sizeof(typeof_member(struct module, build_id)) == 20); + len += sprintf(buffer + len, " %20phN", buildid); + } +#endif + return len + sprintf(buffer + len, "]"); +} #else /* !CONFIG_MODULES... */ static inline struct module *__module_address(unsigned long addr) @@ -818,6 +832,12 @@ void *dereference_module_function_descriptor(struct module *mod, void *ptr) return ptr; } +static inline int fill_name_build_id(char *buffer, char *modname, + int add_buildid, const unsigned char *buildid, + int len) +{ + return 0; +} #endif /* CONFIG_MODULES */ #ifdef CONFIG_SYSFS diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index 57213e1d2349..7762efadf166 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -479,19 +479,8 @@ static int __sprint_symbol(char *buffer, unsigned long address, if (add_offset) len += sprintf(buffer + len, "+%#lx/%#lx", offset, size); - if (modname) { - len += sprintf(buffer + len, " [%s", modname); -#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID) - if (add_buildid && buildid) { - /* build ID should match length of sprintf */ -#if IS_ENABLED(CONFIG_MODULES) - static_assert(sizeof(typeof_member(struct module, build_id)) == 20); -#endif - len += sprintf(buffer + len, " %20phN", buildid); - } -#endif - len += sprintf(buffer + len, "]"); - } + if (modname) + len += fill_name_build_id(buffer, modname, add_buildid, buildid, len); return len; } @@ -586,6 +575,18 @@ int sprint_backtrace_build_id(char *buffer, unsigned long address) return __sprint_symbol(buffer, address, -1, 1, 1); } +int sprint_kallsym_common(char *buffer, unsigned long address, int build_id, + int backtrace, int symbol) +{ + if (backtrace) + return __sprint_symbol(buffer, address, -1, 1, build_id); + + if (symbol) + return __sprint_symbol(buffer, address, 0, 1, build_id); + + return __sprint_symbol(buffer, address, 0, 0, 0); +} + /* To avoid using get_symbol_offset for every symbol, we carry prefix along. */ struct kallsym_iter { loff_t pos; diff --git a/kernel/module.c b/kernel/module.c index 6cea788fd965..5756d31a024b 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1465,12 +1465,10 @@ resolve_symbol_wait(struct module *mod, return ksym; } -#ifdef CONFIG_KALLSYMS static inline bool sect_empty(const Elf_Shdr *sect) { return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0; } -#endif /* * /sys/module/foo/sections stuff @@ -2799,7 +2797,7 @@ static void add_kallsyms(struct module *mod, const struct load_info *info) } #endif /* CONFIG_KALLSYMS */ -#if IS_ENABLED(CONFIG_KALLSYMS) && IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID) +#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID) static void init_build_id(struct module *mod, const struct load_info *info) { const Elf_Shdr *sechdr; diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 7adb8fd4d804..86f7d24af73c 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -1000,33 +1000,92 @@ char *bdev_name(char *buf, char *end, struct block_device *bdev, } #endif +#if !defined(CONFIG_KALLSYMS) && defined(CONFIG_MODULES) +static int sprint_module_info(char *buf, unsigned long value, + int modbuildid, int backtrace, int symbol) +{ + struct module *mod; + unsigned long offset; + void *base; + char *modname; + int len; + const unsigned char *buildid = NULL; + bool add_offset; + + if (is_ksym_addr(value)) + return 0; + + if (backtrace || symbol) + add_offset = true; + else + add_offset = false; + + preempt_disable(); + mod = __module_address(value); + if (mod) { + modname = mod->name; +#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID) + if (modbuildid) + buildid = mod->build_id; +#endif + if (add_offset) { + base = mod->core_layout.base; + offset = value - (unsigned long)base; + } + } + preempt_enable(); + if (!mod) + return 0; + + /* address belongs to module */ + if (add_offset) + len = sprintf(buf, "0x%p+0x%lx", base, offset); + else + len = sprintf(buf, "0x%lx", value); + + return len + fill_name_build_id(buf, modname, modbuildid, buildid, len); +} +#else +static inline int sprint_module_info(char *buf, unsigned long value, + int modbuildid, int backtrace, int symbol) +{ + return 0; +} +#endif + static noinline_for_stack char *symbol_string(char *buf, char *end, void *ptr, struct printf_spec spec, const char *fmt) { unsigned long value; -#ifdef CONFIG_KALLSYMS char sym[KSYM_SYMBOL_LEN]; -#endif + int backtrace = 0, symbol = 0, build_id = 0; if (fmt[1] == 'R') ptr = __builtin_extract_return_addr(ptr); value = (unsigned long)ptr; -#ifdef CONFIG_KALLSYMS - if (*fmt == 'B' && fmt[1] == 'b') - sprint_backtrace_build_id(sym, value); - else if (*fmt == 'B') - sprint_backtrace(sym, value); - else if (*fmt == 'S' && (fmt[1] == 'b' || (fmt[1] == 'R' && fmt[2] == 'b'))) - sprint_symbol_build_id(sym, value); - else if (*fmt != 's') - sprint_symbol(sym, value); - else - sprint_symbol_no_offset(sym, value); + if (fmt[0] == 'B' && fmt[1] == 'b') { + backtrace = 1; + build_id = 1; + } else if (fmt[0] == 'B') + backtrace = 1; + else if (fmt[0] == 'S' && (fmt[1] == 'b' || (fmt[1] == 'R' && fmt[2] == 'b'))) { + symbol = 1; + build_id = 1; + } else if (fmt[0] != 's') + symbol = 1; + else { + /* Do Nothing, no offset */ + } +#ifdef CONFIG_KALLSYMS + sprint_kallsym_common(sym, value, build_id, backtrace, symbol); return string_nocheck(buf, end, sym, spec); #else + if (sprint_module_info(sym, value, build_id, backtrace, symbol)) + return string_nocheck(buf, end, sym, spec); + return special_hex_number(buf, end, value, sizeof(void *)); #endif }

[v3] kallsyms: enhance %pS/s/b printing when KALLSYSMS is disabled

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