Fix devctl generation for core files.

We have a problem with vn_fullpath_global when the file exists. Work
around it by printing the full path if the core file name starts with /,
or current working directory followed by the filename if not.

Sponsored by: Netflix
Differential Review: https://reviews.freebsd.org/D16026
This commit is contained in:
imp 2018-06-27 04:11:09 +00:00
parent 494f812e46
commit dc94188c95

View File

@ -3431,24 +3431,6 @@ corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td,
return (0);
}
static int
coredump_sanitise_path(const char *path)
{
size_t i;
/*
* Only send a subset of ASCII to devd(8) because it
* might pass these strings to sh -c.
*/
for (i = 0; path[i]; i++)
if (!(isalpha(path[i]) || isdigit(path[i])) &&
path[i] != '/' && path[i] != '.' &&
path[i] != '-')
return (0);
return (1);
}
/*
* Dump a process' core. The main routine does some
* policy checking, and creates the name of the coredump;
@ -3469,11 +3451,8 @@ coredump(struct thread *td)
char *name; /* name of corefile */
void *rl_cookie;
off_t limit;
char *data = NULL;
char *fullpath, *freepath = NULL;
size_t len;
static const char comm_name[] = "comm=";
static const char core_name[] = "core=";
struct sbuf *sb;
PROC_LOCK_ASSERT(p, MA_OWNED);
MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td);
@ -3556,23 +3535,35 @@ coredump(struct thread *td)
*/
if (error != 0 || coredump_devctl == 0)
goto out;
len = MAXPATHLEN * 2 + sizeof(comm_name) - 1 +
sizeof(' ') + sizeof(core_name) - 1;
data = malloc(len, M_TEMP, M_WAITOK);
sb = sbuf_new_auto();
if (vn_fullpath_global(td, p->p_textvp, &fullpath, &freepath) != 0)
goto out;
if (!coredump_sanitise_path(fullpath))
goto out;
snprintf(data, len, "%s%s ", comm_name, fullpath);
goto out2;
sbuf_printf(sb, "comm=\"");
devctl_safe_quote_sb(sb, fullpath);
free(freepath, M_TEMP);
freepath = NULL;
if (vn_fullpath_global(td, vp, &fullpath, &freepath) != 0)
goto out;
if (!coredump_sanitise_path(fullpath))
goto out;
strlcat(data, core_name, len);
strlcat(data, fullpath, len);
devctl_notify("kernel", "signal", "coredump", data);
sbuf_printf(sb, "\" core=\"");
/*
* We can't lookup core file vp directly. When we're replacing a core, and
* other random times, we flush the name cache, so it will fail. Instead,
* if the path of the core is relative, add the current dir in front if it.
*/
if (name[0] != '/') {
fullpath = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
if (kern___getcwd(td, fullpath, UIO_SYSSPACE, MAXPATHLEN, MAXPATHLEN) != 0) {
free(fullpath, M_TEMP);
goto out2;
}
devctl_safe_quote_sb(sb, fullpath);
free(fullpath, M_TEMP);
sbuf_putc(sb, '/');
}
devctl_safe_quote_sb(sb, name);
sbuf_printf(sb, "\"");
if (sbuf_finish(sb) == 0)
devctl_notify("kernel", "signal", "coredump", sbuf_data(sb));
out2:
sbuf_delete(sb);
out:
error1 = vn_close(vp, FWRITE, cred, td);
if (error == 0)
@ -3580,8 +3571,6 @@ coredump(struct thread *td)
#ifdef AUDIT
audit_proc_coredump(td, name, error);
#endif
free(freepath, M_TEMP);
free(data, M_TEMP);
free(name, M_TEMP);
return (error);
}