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-rw-r--r--fs/coredump.c121
1 files changed, 59 insertions, 62 deletions
diff --git a/fs/coredump.c b/fs/coredump.c
index dafafbafa731..72f816d6cad9 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -45,69 +45,79 @@
#include <trace/events/sched.h>
int core_uses_pid;
-char core_pattern[CORENAME_MAX_SIZE] = "core";
unsigned int core_pipe_limit;
+char core_pattern[CORENAME_MAX_SIZE] = "core";
+static int core_name_size = CORENAME_MAX_SIZE;
struct core_name {
char *corename;
int used, size;
};
-static atomic_t call_count = ATOMIC_INIT(1);
/* The maximal length of core_pattern is also specified in sysctl.c */
-static int expand_corename(struct core_name *cn)
+static int expand_corename(struct core_name *cn, int size)
{
- char *old_corename = cn->corename;
-
- cn->size = CORENAME_MAX_SIZE * atomic_inc_return(&call_count);
- cn->corename = krealloc(old_corename, cn->size, GFP_KERNEL);
+ char *corename = krealloc(cn->corename, size, GFP_KERNEL);
- if (!cn->corename) {
- kfree(old_corename);
+ if (!corename)
return -ENOMEM;
- }
+ if (size > core_name_size) /* racy but harmless */
+ core_name_size = size;
+
+ cn->size = ksize(corename);
+ cn->corename = corename;
return 0;
}
+static int cn_vprintf(struct core_name *cn, const char *fmt, va_list arg)
+{
+ int free, need;
+
+again:
+ free = cn->size - cn->used;
+ need = vsnprintf(cn->corename + cn->used, free, fmt, arg);
+ if (need < free) {
+ cn->used += need;
+ return 0;
+ }
+
+ if (!expand_corename(cn, cn->size + need - free + 1))
+ goto again;
+
+ return -ENOMEM;
+}
+
static int cn_printf(struct core_name *cn, const char *fmt, ...)
{
- char *cur;
- int need;
- int ret;
va_list arg;
+ int ret;
va_start(arg, fmt);
- need = vsnprintf(NULL, 0, fmt, arg);
+ ret = cn_vprintf(cn, fmt, arg);
va_end(arg);
- if (likely(need < cn->size - cn->used - 1))
- goto out_printf;
+ return ret;
+}
- ret = expand_corename(cn);
- if (ret)
- goto expand_fail;
+static int cn_esc_printf(struct core_name *cn, const char *fmt, ...)
+{
+ int cur = cn->used;
+ va_list arg;
+ int ret;
-out_printf:
- cur = cn->corename + cn->used;
va_start(arg, fmt);
- vsnprintf(cur, need + 1, fmt, arg);
+ ret = cn_vprintf(cn, fmt, arg);
va_end(arg);
- cn->used += need;
- return 0;
-expand_fail:
+ for (; cur < cn->used; ++cur) {
+ if (cn->corename[cur] == '/')
+ cn->corename[cur] = '!';
+ }
return ret;
}
-static void cn_escape(char *str)
-{
- for (; *str; str++)
- if (*str == '/')
- *str = '!';
-}
-
static int cn_print_exe_file(struct core_name *cn)
{
struct file *exe_file;
@@ -115,12 +125,8 @@ static int cn_print_exe_file(struct core_name *cn)
int ret;
exe_file = get_mm_exe_file(current->mm);
- if (!exe_file) {
- char *commstart = cn->corename + cn->used;
- ret = cn_printf(cn, "%s (path unknown)", current->comm);
- cn_escape(commstart);
- return ret;
- }
+ if (!exe_file)
+ return cn_esc_printf(cn, "%s (path unknown)", current->comm);
pathbuf = kmalloc(PATH_MAX, GFP_TEMPORARY);
if (!pathbuf) {
@@ -134,9 +140,7 @@ static int cn_print_exe_file(struct core_name *cn)
goto free_buf;
}
- cn_escape(path);
-
- ret = cn_printf(cn, "%s", path);
+ ret = cn_esc_printf(cn, "%s", path);
free_buf:
kfree(pathbuf);
@@ -157,19 +161,19 @@ static int format_corename(struct core_name *cn, struct coredump_params *cprm)
int pid_in_pattern = 0;
int err = 0;
- cn->size = CORENAME_MAX_SIZE * atomic_read(&call_count);
- cn->corename = kmalloc(cn->size, GFP_KERNEL);
cn->used = 0;
-
- if (!cn->corename)
+ cn->corename = NULL;
+ if (expand_corename(cn, core_name_size))
return -ENOMEM;
+ cn->corename[0] = '\0';
+
+ if (ispipe)
+ ++pat_ptr;
/* Repeat as long as we have more pattern to process and more output
space */
while (*pat_ptr) {
if (*pat_ptr != '%') {
- if (*pat_ptr == 0)
- goto out;
err = cn_printf(cn, "%c", *pat_ptr++);
} else {
switch (*++pat_ptr) {
@@ -210,22 +214,16 @@ static int format_corename(struct core_name *cn, struct coredump_params *cprm)
break;
}
/* hostname */
- case 'h': {
- char *namestart = cn->corename + cn->used;
+ case 'h':
down_read(&uts_sem);
- err = cn_printf(cn, "%s",
+ err = cn_esc_printf(cn, "%s",
utsname()->nodename);
up_read(&uts_sem);
- cn_escape(namestart);
break;
- }
/* executable */
- case 'e': {
- char *commstart = cn->corename + cn->used;
- err = cn_printf(cn, "%s", current->comm);
- cn_escape(commstart);
+ case 'e':
+ err = cn_esc_printf(cn, "%s", current->comm);
break;
- }
case 'E':
err = cn_print_exe_file(cn);
break;
@@ -244,6 +242,7 @@ static int format_corename(struct core_name *cn, struct coredump_params *cprm)
return err;
}
+out:
/* Backward compatibility with core_uses_pid:
*
* If core_pattern does not include a %p (as is the default)
@@ -254,7 +253,6 @@ static int format_corename(struct core_name *cn, struct coredump_params *cprm)
if (err)
return err;
}
-out:
return ispipe;
}
@@ -549,7 +547,7 @@ void do_coredump(siginfo_t *siginfo)
if (ispipe < 0) {
printk(KERN_WARNING "format_corename failed\n");
printk(KERN_WARNING "Aborting core\n");
- goto fail_corename;
+ goto fail_unlock;
}
if (cprm.limit == 1) {
@@ -584,7 +582,7 @@ void do_coredump(siginfo_t *siginfo)
goto fail_dropcount;
}
- helper_argv = argv_split(GFP_KERNEL, cn.corename+1, NULL);
+ helper_argv = argv_split(GFP_KERNEL, cn.corename, NULL);
if (!helper_argv) {
printk(KERN_WARNING "%s failed to allocate memory\n",
__func__);
@@ -601,7 +599,7 @@ void do_coredump(siginfo_t *siginfo)
argv_free(helper_argv);
if (retval) {
- printk(KERN_INFO "Core dump to %s pipe failed\n",
+ printk(KERN_INFO "Core dump to |%s pipe failed\n",
cn.corename);
goto close_fail;
}
@@ -669,7 +667,6 @@ fail_dropcount:
atomic_dec(&core_dump_count);
fail_unlock:
kfree(cn.corename);
-fail_corename:
coredump_finish(mm, core_dumped);
revert_creds(old_cred);
fail_creds:
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