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Thu, 21 Apr 2022 04:16:04 +0000 (GMT) Received: from epsmgms1p2.samsung.com (unknown [182.195.42.42]) by epsmtrp2.samsung.com (KnoxPortal) with ESMTP id 20220421041604epsmtrp279afb081ee7b7024bdd255f635e8562c~nzkB9GmeS0572705727epsmtrp28; Thu, 21 Apr 2022 04:16:04 +0000 (GMT) X-AuditID: b6c32a4b-4b5ff700000226e0-eb-6260da99e803 Received: from epsmtip1.samsung.com ( [182.195.34.30]) by epsmgms1p2.samsung.com (Symantec Messaging Gateway) with SMTP id 85.C3.03370.48AD0626; Thu, 21 Apr 2022 13:16:04 +0900 (KST) Received: from localhost.localdomain (unknown [107.109.224.44]) by epsmtip1.samsung.com (KnoxPortal) with ESMTPA id 20220421041601epsmtip12ab9193fefba212f272bbabd8c0cd14e~nzj-FNF4X0994209942epsmtip1H; Thu, 21 Apr 2022 04:16:01 +0000 (GMT) From: Maninder Singh 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.or, linux-kernel@vger.kernel.org, linux-modules@vger.kernel.org, avimalin@gmail.com, atomlin@redhat.com, onkarnath.1@samsung.com, Maninder Singh Subject: [PATCH modules-next 1/1] kallsyms: enhance %pS/s/b printing when KALLSYSMS is disabled Date: Thu, 21 Apr 2022 09:45:42 +0530 Message-Id: <20220421041542.9195-1-maninder1.s@samsung.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrEKsWRmVeSWpSXmKPExsWy7bCmpu7MWwlJBlt/81nMWb+GzaK3aTqT xZH5a1gtHhy8zm5xedccNouG2d9ZLR7PmsdmcXh+G4vFjQlPGS1mfgEqWdHzgdXi/+OvrBb7 Oh4wWezeuIjN4vidp0wWh07OZbRo/Hyf0UHQY3bDRRaPnbPusnu07LsFJI68ZfX4cv08o8em VZ1sHidm/GbxmHcy0ONCV7bH+31X2Tz6tqxi9Fi/5SqLx+dNcgG8UVw2Kak5mWWpRfp2CVwZ NzfMYS1oTai42L6YvYFxt38XIyeHhICJRP+fuWxdjFwcQgK7GSWu/nvHDOF8YpQ4uO8jE4Tz mVGi6+IBdpiWC73/2CESuxglJs08DdX/hVFiwvGzrCBVbAJ6Eqt27WEBSYgIXGCUuHJrD9hg ZoE3jBJ3PzaCVQkLJEp8mf+YDcRmEVCVeL7nKAuIzStgLTFrYj8LxD55iZmXvrNDxAUlTs58 AhZnBoo3b53NDFFzgkNi/28rCNtFonP2HSYIW1ji1fEtUHdLSXx+txdoFweQXS6xdUI9yD0S Ai2MEvvnTGGDqLGXeHJxIStIDbOApsT6XfoQYVmJqafWMUGs5ZPo/f0EajyvxI55MLaqRMvN DawQtrTE548foc73kGj68wisRkggVuLglPOMExjlZyH5ZhaSb2YhbF7AyLyKUTK1oDg3PbXY tMA4L7Vcrzgxt7g0L10vOT93EyM4GWp572B89OCD3iFGJg7GQ4wSHMxKIryhM+OThHhTEiur Uovy44tKc1KLDzFKc7AoifOeSt+QKCSQnliSmp2aWpBaBJNl4uCUamBS2LCx3miVmIfsIVbJ jX8uJe5frvaszyDSZLG9eaqk+PWVsZ5b7sqX3XFyWzHh75Ubm8N5vc31b82+ZODlHbBSi/vh JM4T5l8vpN8XvXst37Xji+atFV6KQtoXdC+sys85m69pmfIx4XPF9uOM/0I6e6+42a+oXMZ8 1LXA3MtX4X2uJuuXBRFRPJKTFgs7+y1Y3uXBqamsvOphmfS5jEKLZEkpNQ7Znc1rny9/ffrf uuV7nm9Y8dKrqLcv2mFPhnQDe9BZcfV5G6Ue1IQvm5Ixy9/j9gL7R0lhx/L6WXYe6he0S50a 967i85RJ0rXPlf4IfJD33H7p/bpJbO5H9KYdn2hbtvzp4+wLK0UdpxoosRRnJBpqMRcVJwIA V0CqjvUDAAA= X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFmpnkeLIzCtJLcpLzFFi42LZdlhJTrflVkKSQfN6XYs569ewWfQ2TWey ODJ/DavFg4PX2S0u75rDZtEw+zurxeNZ89gsDs9vY7G4MeEpo8XML0AlK3o+sFr8f/yV1WJf xwMmi90bF7FZHL/zlMni0Mm5jBaNn+8zOgh6zG64yOKxc9Zddo+WfbeAxJG3rB5frp9n9Ni0 qpPN48SM3ywe804GelzoyvZ4v+8qm0ffllWMHuu3XGXx+LxJLoA3issmJTUnsyy1SN8ugSvj 5oY5rAWtCRUX2xezNzDu9u9i5OSQEDCRuND7jx3EFhLYwSjx+2gSRFxa4ue/9ywQtrDEyn/P gWq4gGo+MUrc7ZsJ1sAmoCexatceFpCEiMANRonFCzuZQRLMAt8YJfa054PYwgLxEvc+dYI1 sAioSjzfcxRsKq+AtcSsif1QG+QlZl76zg4RF5Q4OfMJC8QceYnmrbOZJzDyzUKSmoUktYCR aRWjZGpBcW56brFhgVFearlecWJucWleul5yfu4mRnBcaWntYNyz6oPeIUYmDsZDjBIczEoi vKEz45OEeFMSK6tSi/Lji0pzUosPMUpzsCiJ817oOhkvJJCeWJKanZpakFoEk2Xi4JRqYDoe tT/mtp61KWfGn38LFvfsap2nvJ1TsNzsuVuFg1z74uZTz5zur1jEvvNUa09f7RSvU9v4dxXt WPl106ujfiFv7Blj1udwHZk9Z9n+51VsB9RO579m9Nti+YZf5+9eodzHjOK+Bvb5nsnCj+UY Z0m3R6wXZjinX/JdLsP79JfWVW3flXOLvlb2dwXy3Not5/7kfF/QhoiIZIObwSt+nrh445Pv hvt1h6zZmSZxSsspV4TU+U38Jf7iy6aW2KN2DdOWOkas9DHvmNHhlR7avJjv4fcSw7mu9gsX BDaV79qxZuKS+6cyHN/4rHX9ZttUdnghm7//7CWNgVvbrNgUteZznBK4pX3IL7hpz4YWCSWW 4oxEQy3mouJEAPi2BUIaAwAA X-CMS-MailID: 20220421041604epcas5p414cf2e851d1bd828a151dc6b2b004680 X-Msg-Generator: CA X-Sendblock-Type: REQ_APPROVE CMS-TYPE: 105P X-CMS-RootMailID: 20220421041604epcas5p414cf2e851d1bd828a151dc6b2b004680 References: Precedence: bulk List-ID: print module information when KALLSYMS is disabled. init_build_id() function is moved to module/main.c as it can be independent of kallsyms. No change for %pB, as it needs to know symbol name to adjust address value which can't be done without KALLSYMS. (A) original output with KALLSYMS: [8.842129] ps function_1 [crash] [8.842735] pS function_1+0x4/0x2c [crash] [8.842890] pSb function_1+0x4/0x2c [crash b367e79021b9f3b0172f9a36d4261c1f528ca1b3] [8.843175] pB function_1+0x4/0x2c [crash] [8.843362] pBb function_1+0x4/0x2c [crash b367e79021b9f3b0172f9a36d4261c1f528ca1b3] (B) original output without KALLSYMS: [12.487424] ps 0xffff800000eb008c [12.487598] pS 0xffff800000eb008c [12.487723] pSb 0xffff800000eb008c [12.487850] pB 0xffff800000eb008c [12.487967] pBb 0xffff800000eb008c (C) With patched kernel with KALLYSMS: [41.974576] ps function_1 [crash] [41.975173] pS function_1+0x4/0x2c [crash] [41.975386] pSb function_1+0x4/0x2c [crash a8b20caaec9635b316cf4812f6b55598fe2b7cee] [41.975879] pB function_1+0x4/0x2c [crash] [41.976076] pBb function_1+0x4/0x2c [crash a8b20caaec9635b316cf4812f6b55598fe2b7cee] without KALLSYMS: [9.624152] ps 0xffff800001bd008c [crash] // similar to original, no changes [9.624548] pS 0x(____ptrval____)+0x8c [crash] // base address hashed and offset is without hash [9.624847] pSb 0x(____ptrval____)+0x8c [crash a8b20caaec9635b316cf4812f6b55598fe2b7cee] [9.625388] pB 0x(____ptrval____)+0x8c [crash] [9.625594] pBb 0x(____ptrval____)+0x8c [crash a8b20caaec9635b316cf4812f6b55598fe2b7cee] with disable hashing: [8.563916] ps 0xffff800000f2008c [crash] [8.564574] pS 0xffff800000f20000+0x8c [crash] [8.564749] pSb 0xffff800000f20000+0x8c [crash 3423a8993a7033fb79e5add14bf9d8d6b56330ca] [8.565008] pB 0xffff800000f20000+0x8c [crash] [8.565154] pBb 0xffff800000f20000+0x8c [crash 3423a8993a7033fb79e5add14bf9d8d6b56330ca] Suggested-by: Petr Mladek Co-developed-by: Vaneet Narang Signed-off-by: Vaneet Narang Signed-off-by: Maninder Singh Reviewed-by: Petr Mladek Tested-by: Petr Mladek --- include/linux/kallsyms.h | 2 + include/linux/module.h | 20 ++++++++++ kernel/kallsyms.c | 27 +++++++------ kernel/module/internal.h | 11 +++--- kernel/module/kallsyms.c | 20 ---------- kernel/module/main.c | 20 ++++++++++ lib/vsprintf.c | 85 ++++++++++++++++++++++++++++++++++------ 7 files changed, 133 insertions(+), 52 deletions(-) diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h index ce1bd2fbf23e..72bd24e80545 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 46d4d5f2516e..66f4491249c5 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -682,6 +682,20 @@ static inline bool is_livepatch_module(struct module *mod) 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 79f2eb617a62..e6e96b2e0257 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -465,19 +465,8 @@ 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; } @@ -572,6 +561,18 @@ 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/internal.h b/kernel/module/internal.h index 3e23bef5884d..cfff130f7c5f 100644 --- a/kernel/module/internal.h +++ b/kernel/module/internal.h @@ -206,21 +206,20 @@ static inline void kmemleak_load_module(const struct module *mod, #endif /* CONFIG_DEBUG_KMEMLEAK */ #ifdef CONFIG_KALLSYMS -void init_build_id(struct module *mod, const struct load_info *info); void layout_symtab(struct module *mod, struct load_info *info); void add_kallsyms(struct module *mod, const struct load_info *info); unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name); -static inline bool sect_empty(const Elf_Shdr *sect) -{ - return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0; -} #else /* !CONFIG_KALLSYMS */ -static inline void init_build_id(struct module *mod, const struct load_info *info) { } static inline void layout_symtab(struct module *mod, struct load_info *info) { } static inline void add_kallsyms(struct module *mod, const struct load_info *info) { } #endif /* CONFIG_KALLSYMS */ +static inline bool sect_empty(const Elf_Shdr *sect) +{ + return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0; +} + #ifdef CONFIG_SYSFS int mod_sysfs_setup(struct module *mod, const struct load_info *info, struct kernel_param *kparam, unsigned int num_params); diff --git a/kernel/module/kallsyms.c b/kernel/module/kallsyms.c index 3e11523bc6f6..576a597615a7 100644 --- a/kernel/module/kallsyms.c +++ b/kernel/module/kallsyms.c @@ -209,26 +209,6 @@ void add_kallsyms(struct module *mod, const struct load_info *info) mod->core_kallsyms.num_symtab = ndst; } -#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID) -void init_build_id(struct module *mod, const struct load_info *info) -{ - const Elf_Shdr *sechdr; - unsigned int i; - - for (i = 0; i < info->hdr->e_shnum; i++) { - sechdr = &info->sechdrs[i]; - if (!sect_empty(sechdr) && sechdr->sh_type == SHT_NOTE && - !build_id_parse_buf((void *)sechdr->sh_addr, mod->build_id, - sechdr->sh_size)) - break; - } -} -#else -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. diff --git a/kernel/module/main.c b/kernel/module/main.c index 05a42d8fcd7a..d511a9c62b53 100644 --- a/kernel/module/main.c +++ b/kernel/module/main.c @@ -2657,6 +2657,26 @@ static int unknown_module_param_cb(char *param, char *val, const char *modname, static void cfi_init(struct module *mod); +#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID) +static void init_build_id(struct module *mod, const struct load_info *info) +{ + const Elf_Shdr *sechdr; + unsigned int i; + + for (i = 0; i < info->hdr->e_shnum; i++) { + sechdr = &info->sechdrs[i]; + if (!sect_empty(sechdr) && sechdr->sh_type == SHT_NOTE && + !build_id_parse_buf((void *)sechdr->sh_addr, mod->build_id, + sechdr->sh_size)) + break; + } +} +#else +static inline void init_build_id(struct module *mod, const struct load_info *info) +{ +} +#endif + /* * Allocate and load the module: note that size of section 0 is always * zero, and we rely on this for optional sections. diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 40d26a07a133..e0aba2c80b8e 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -999,33 +999,92 @@ 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 }