From 57cc083ad9e1bfeeb4a0ee831e7bb008c8865bf0 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Thu, 26 May 2011 16:25:46 -0700 Subject: [PATCH] coredump: add support for exe_file in core name Now, exe_file is not proc FS dependent, so we can use it to name core file. So we add %E pattern for core file name cration which extract path from mm_struct->exe_file. Then it converts slashes to exclamation marks and pastes the result to the core file name itself. This is useful for environments where binary names are longer than 16 character (the current->comm limitation). Also where there are binaries with same name but in a different path. Further in case the binery itself changes its current->comm after exec. So by doing (s/$/#/ -- # is treated as git comment): $ sysctl kernel.core_pattern='core.%p.%e.%E' $ ln /bin/cat cat45678901234567890 $ ./cat45678901234567890 ^Z $ rm cat45678901234567890 $ fg ^\Quit (core dumped) $ ls core* we now get: core.2434.cat456789012345.!root!cat45678901234567890 (deleted) Signed-off-by: Jiri Slaby Cc: Al Viro Cc: Alan Cox Reviewed-by: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/sysctl/kernel.txt | 3 ++- fs/exec.c | 38 +++++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+), 1 deletion(-) diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index 36f007514db3..5e7cb39ad195 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -161,7 +161,8 @@ core_pattern is used to specify a core dumpfile pattern name. %s signal number %t UNIX time of dump %h hostname - %e executable filename + %e executable filename (may be shortened) + %E executable path % both are dropped . If the first character of the pattern is a '|', the kernel will treat the rest of the pattern as a command to run. The core dump will be diff --git a/fs/exec.c b/fs/exec.c index 88a16c572282..ea5f748906a8 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1623,6 +1623,41 @@ expand_fail: return ret; } +static int cn_print_exe_file(struct core_name *cn) +{ + struct file *exe_file; + char *pathbuf, *path, *p; + int ret; + + exe_file = get_mm_exe_file(current->mm); + if (!exe_file) + return cn_printf(cn, "(unknown)"); + + pathbuf = kmalloc(PATH_MAX, GFP_TEMPORARY); + if (!pathbuf) { + ret = -ENOMEM; + goto put_exe_file; + } + + path = d_path(&exe_file->f_path, pathbuf, PATH_MAX); + if (IS_ERR(path)) { + ret = PTR_ERR(path); + goto free_buf; + } + + for (p = path; *p; p++) + if (*p == '/') + *p = '!'; + + ret = cn_printf(cn, "%s", path); + +free_buf: + kfree(pathbuf); +put_exe_file: + fput(exe_file); + return ret; +} + /* format_corename will inspect the pattern parameter, and output a * name into corename, which must have space for at least * CORENAME_MAX_SIZE bytes plus one byte for the zero terminator. @@ -1694,6 +1729,9 @@ static int format_corename(struct core_name *cn, long signr) case 'e': err = cn_printf(cn, "%s", current->comm); break; + case 'E': + err = cn_print_exe_file(cn); + break; /* core limit size */ case 'c': err = cn_printf(cn, "%lu", -- 2.20.1