library: provide for huge cmdlines, like old libproc

The CodingStyle document suggests programs should allow for
cmdlines of at least 128k.  Only the ps program can display
such a cmdline, and only with multiple -w switches.

The library function file2strvec can essentially return
a cmdline of unlimited length.  However, the library function
fill_cmdline_cvt used an arbitrary upper limit of 2048 for
buffers automatically allocated on the stack.

This patch raises the fill_cmdline_cvt upper limit to 128k via
dymaically acquired utility buffers ensured by the openproc
function.

It also makes indentation consistent in the openproc function.
This commit is contained in:
Jim Warner 2011-12-02 03:47:19 -06:00 committed by Craig Small
parent 827334870d
commit ed59472307

View File

@ -42,6 +42,12 @@ extern void __cyg_profile_func_enter(void*,void*);
#define IS_THREAD(q) ( q->pad_1 == '\xee' )
#endif
// utility buffers of MAX_BUFSZ bytes each, available to
// any function following an openproc() call
static char *src_buffer,
*dst_buffer;
#define MAX_BUFSZ 1024*64*2
#ifndef SIGNAL_STRING
// convert hex string to unsigned long long
static unsigned long long unhex(const char *restrict cp){
@ -660,14 +666,13 @@ static void fill_cgroup_cvt (const char* directory, proc_t *restrict p) {
// and guarantees the caller a valid proc_t.cmdline pointer.
static void fill_cmdline_cvt (const char* directory, proc_t *restrict p) {
#define uFLG ( ESC_BRACKETS | ESC_DEFUNCT )
char sbuf[2048], dbuf[2048];
int whackable_int = sizeof(dbuf);
int whackable_int = MAX_BUFSZ;
if (read_unvectored(sbuf, sizeof(sbuf), directory, "cmdline", ' '))
escape_str(dbuf, sbuf, sizeof(dbuf), &whackable_int);
if (read_unvectored(src_buffer, MAX_BUFSZ, directory, "cmdline", ' '))
escape_str(dst_buffer, src_buffer, MAX_BUFSZ, &whackable_int);
else
escape_command(dbuf, p, sizeof(dbuf), &whackable_int, uFLG);
p->cmdline = vectorize_this_str(dbuf);
escape_command(dst_buffer, p, MAX_BUFSZ, &whackable_int, uFLG);
p->cmdline = vectorize_this_str(dst_buffer);
#undef uFLG
}
@ -1155,15 +1160,19 @@ PROCTAB* openproc(int flags, ...) {
}
PT->flags = flags;
va_start(ap, flags); /* Init args list */
va_start(ap, flags);
if (flags & PROC_PID)
PT->pids = va_arg(ap, pid_t*);
else if (flags & PROC_UID){
PT->uids = va_arg(ap, uid_t*);
PT->nuid = va_arg(ap, int);
}
va_end(ap); /* Clean up args list */
va_end(ap);
if (!src_buffer){
src_buffer = xmalloc(MAX_BUFSZ);
dst_buffer = xmalloc(MAX_BUFSZ);
}
return PT;
}
@ -1365,3 +1374,4 @@ proc_t * get_proc_stats(pid_t pid, proc_t *p) {
#undef MK_THREAD
#undef IS_THREAD
#undef MAX_BUFSZ