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Mon, 08 Aug 2022 15:09:18 +0200 From: Helge Deller To: linux-s390@vger.kernel.org, Josh Triplett , x86@kernel.org, linux-snps-arc@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH v3 2/4] lib/dump_stack: Add dump_stack_print_cmdline() and wire up in dump_stack_print_info() Date: Mon, 8 Aug 2022 15:09:15 +0200 Message-Id: <20220808130917.30760-3-deller@gmx.de> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220808130917.30760-1-deller@gmx.de> References: <20220808130917.30760-1-deller@gmx.de> MIME-Version: 1.0 X-Provags-ID: V03:K1:dyv38+4Ugz+oNJYhEqwA1WGPLQMQCHxH7gYA9DzhxE1ZyTHPUeX lgD4MbyXnzij2je0A21JveizFDJ0RysmHlBxi1vdTStYEm+RmHzoUuMstEW+hD9FO33SxJr oP2WdouS9nQ1WcoKEklsuUfDBg9/nB9mx5tSBtp94vcEnDi6cGYPDjwHjZ/7PA8qYfqxH+H F9wPqtQXlYJ80YG68DQag== X-UI-Out-Filterresults: notjunk:1;V03:K0:RpW0RFU0Z6E=:vHBeUsc70DYciJo0r3uauF MGJOW+2JX5iPyl7bzACYuZzcsgE0KOuDtO1K2Bppk4muzBADa/0UwkNWZnhnxq9gctbdzfM2F CjYlu/8hoQK8Rp2oi6uDjx0cvEw7fMo5WqUcUNzy/eq+XjoGQFk9oFfC6s4hJjWMIRGQtNjNM QcPSX8jSs3qP0DmNaFDGPankZ4Q+5EQr/+5SXjaSpwz59qzcyhuXKBV56vrYGFvdclmephBIq B7oxtrb2uaCWI+kvsoNLs/zrQv1fWspOyVBYQASk4fWO7nDttW8eUVv+FGqWNewFLKdxYj1Cx 17xFxjhqi6jg4+258yvMd3QGes7U/5INRI5An1vrAxJH5fzxnwNa5zPcFWDdXr6824deE2ODO OnIvUA2lLkfbK+8WKDyeLKZvsnoifbZDBBXzHpy94LePbuI+4LeFGkvBQAXgWh89djmnICx+I bklL2SCdn6+Dj4mOle7BQzRhIdtZGFKKjmcbGFkOQ9mhbF/AEA0+p6vxkBh3l+Sg7YCaET3rX Cvn6uoFNHsLPmIGhUZ9naF1Tg1Utleqnayp70ND3Y/8G6eYDBwrdmJ09KCKMJLksREGa9gCLw QGLTi8C+auExK41IXHRYB1YmxVCytlyQkZpRSoEB0K4iKVRvdBlP1PMJMsR2YfYUG807KDgnx vytnyNGsCYDOSI8kcQLPdUWHRcUehw5OAt9bVZBM09KlvsDZOafd89xsjR8n+hQLQDgQXIv79 EVl4Fwge064DHAD7FCCY1/yuzwgRafYs3caT3EgYOx0FP9ExsGBPef5/Xjz4gUcxhQ7xEAvEG 1Yq4ZjOoSQ+WCbrKx2ftLQmfGPZLqor0mdgKBg/sfVEHQs6h0Qs8QYWVvlhaQIbWLavN+/5uV 5FQmjRtWTcUL1tqvnWnOjjYl+4E41TpDG/r1W4ZyXt6usjTpUUKxzAbU1plRO4KLbMjfe6iGo OAVHd7w4z5xUq0GYnj0ApSE32SJ0q2AEhGU1eprIAN5I2PHSYdUvVzglD8DT1HnByn9qhqba9 GfWGIRaNOFib7OQV8Uetfbqt4SniAEFZaEgLv2Vtvka4Z3i1FSZNu7FnWZKiSg3tCWc1Z0Rw1 twVCPi6Gum3G2ewQ5/3id79oC2uC0VmtWK+w4iwrz3W4P9YWwp/BHym5w== X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220808_060929_732247_9DCC399E X-CRM114-Status: GOOD ( 17.69 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Add the function dump_stack_print_cmdline() which can be used by arch code to print the command line of the current processs. This function is useful in arch code when dumping information for a faulting process. Wire this function up in the dump_stack_print_info() function to include the dumping of the command line for architectures which use dump_stack_print_info(). As an example, with this patch a failing glibc testcase (which uses ld.so.1 as starting program) up to now reported just "ld.so.1" failing: do_page_fault() command='ld.so.1' type=15 address=0x565921d8 in libc.so[f7339000+1bb000] trap #15: Data TLB miss fault, vm_start = 0x0001a000, vm_end = 0x0001b000 and now it reports in addition: ld.so.1[1151] cmdline: /home/gnu/glibc/objdir/elf/ld.so.1 --library-path /home/gnu/glibc/objdir:/home/gnu/glibc/objdir/math:/home/gnu/ /home/gnu/glibc/objdir/malloc/tst-safe-linking-malloc-hugetlb1 Josh Triplett noted that dumping such command line parameters into syslog may theoretically lead to information disclosure. That's why this patch checks the value of the kptr_restrict sysctl variable and will not print any information if kptr_restrict==2, and will not show the program parameters if kptr_restrict==1. Signed-off-by: Helge Deller --- include/linux/printk.h | 5 +++++ lib/dump_stack.c | 34 ++++++++++++++++++++++++++++++++++ 2 files changed, 39 insertions(+) -- 2.37.1 diff --git a/include/linux/printk.h b/include/linux/printk.h index cf7d666ab1f8..5290a32a197d 100644 --- a/include/linux/printk.h +++ b/include/linux/printk.h @@ -191,6 +191,7 @@ u32 log_buf_len_get(void); void log_buf_vmcoreinfo_setup(void); void __init setup_log_buf(int early); __printf(1, 2) void dump_stack_set_arch_desc(const char *fmt, ...); +void dump_stack_print_cmdline(const char *log_lvl); void dump_stack_print_info(const char *log_lvl); void show_regs_print_info(const char *log_lvl); extern asmlinkage void dump_stack_lvl(const char *log_lvl) __cold; @@ -262,6 +263,10 @@ static inline __printf(1, 2) void dump_stack_set_arch_desc(const char *fmt, ...) { } +static inline void dump_stack_print_cmdline(const char *log_lvl) +{ +} + static inline void dump_stack_print_info(const char *log_lvl) { } diff --git a/lib/dump_stack.c b/lib/dump_stack.c index 83471e81501a..38ef1067c7eb 100644 --- a/lib/dump_stack.c +++ b/lib/dump_stack.c @@ -14,6 +14,7 @@ #include #include #include +#include static char dump_stack_arch_desc_str[128]; @@ -45,6 +46,37 @@ void __init dump_stack_set_arch_desc(const char *fmt, ...) #define BUILD_ID_VAL "" #endif +/** + * dump_stack_print_cmdline - print the command line of current process + * @log_lvl: log level + */ +void dump_stack_print_cmdline(const char *log_lvl) +{ + char cmdline[256]; + + if (kptr_restrict >= 2) + return; /* never show command line */ + + /* get command line */ + get_task_cmdline_kernel(current, cmdline, sizeof(cmdline)); + + if (kptr_restrict == 1) { + char *p; + + /* if restricted show program path only */ + p = strchr(cmdline, ' '); + if (p) { + *p = 0; + strlcat(cmdline, + " ... [parameters hidden due to kptr_restrict]", + sizeof(cmdline)); + } + } + + printk("%s%s[%d] cmdline: %s\n", log_lvl, current->comm, + current->pid, cmdline); +} + /** * dump_stack_print_info - print generic debug info for dump_stack() * @log_lvl: log level @@ -62,6 +94,8 @@ void dump_stack_print_info(const char *log_lvl) (int)strcspn(init_utsname()->version, " "), init_utsname()->version, BUILD_ID_VAL); + dump_stack_print_cmdline(log_lvl); + if (dump_stack_arch_desc_str[0] != '\0') printk("%sHardware name: %s\n", log_lvl, dump_stack_arch_desc_str);