diff options
author | William Roberts | 2014-02-11 10:11:59 -0800 |
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committer | Eric Paris | 2014-03-07 11:52:45 -0500 |
commit | a90902531a06a030a252a07fbff7f45a189a64fe (patch) | |
tree | 676cd6bd7530f5187af569baf93a138d085737c0 /mm | |
parent | 147d2601d8fabf9451364f2d58098530a37eb3c9 (diff) |
mm: Create utility function for accessing a tasks commandline value
introduce get_cmdline() for retreiving the value of a processes
proc/self/cmdline value.
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: William Roberts <wroberts@tresys.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/util.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/mm/util.c b/mm/util.c index 808f375648e7..43b44199c5e3 100644 --- a/mm/util.c +++ b/mm/util.c @@ -413,6 +413,54 @@ unsigned long vm_commit_limit(void) * sysctl_overcommit_ratio / 100) + total_swap_pages; } +/** + * get_cmdline() - copy the cmdline value to a buffer. + * @task: the task whose cmdline value to copy. + * @buffer: the buffer to copy to. + * @buflen: the length of the buffer. Larger cmdline values are truncated + * to this length. + * Returns the size of the cmdline field copied. Note that the copy does + * not guarantee an ending NULL byte. + */ +int get_cmdline(struct task_struct *task, char *buffer, int buflen) +{ + int res = 0; + unsigned int len; + struct mm_struct *mm = get_task_mm(task); + if (!mm) + goto out; + if (!mm->arg_end) + goto out_mm; /* Shh! No looking before we're done */ + + len = mm->arg_end - mm->arg_start; + + if (len > buflen) + len = buflen; + + res = access_process_vm(task, mm->arg_start, buffer, len, 0); + + /* + * If the nul at the end of args has been overwritten, then + * assume application is using setproctitle(3). + */ + if (res > 0 && buffer[res-1] != '\0' && len < buflen) { + len = strnlen(buffer, res); + if (len < res) { + res = len; + } else { + len = mm->env_end - mm->env_start; + if (len > buflen - res) + len = buflen - res; + res += access_process_vm(task, mm->env_start, + buffer+res, len, 0); + res = strnlen(buffer, res); + } + } +out_mm: + mmput(mm); +out: + return res; +} /* Tracepoints definitions. */ EXPORT_TRACEPOINT_SYMBOL(kmalloc); |