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procps/proc/readproc.c
Jaromir Capik ae9676a337 library: skip replacement of trailing '\0' in read_unvectored() 
Under some circumstances the ksh shell doesn't fork new processes
when executing scripts and the script is interpreted by the
parent process. That makes the execution faster, but it means
ksh needs to reuse the /proc/PID/cmdline for the new script name
and arguments while the file length needs to stay untouched.
The fork is skipped only when the new cmdline is shorter than
the parent's cmdline and the rest of the file is filled
with '\0'. This is perfectly ok until we try to read the cmdline
of such process. As the read_unvectored() function replaces
all zeros with chosen separator, these trailing zeros are replaced
with spaces in case of the ps tool. Consequently it appends
multiple spaces at the end of the arguments string even when these
zeros do not represent any separators and therefore shouldn't
be replaced.
With this commit the read_unvectored() function skips the
replacement of trailing zeros and separates valid content only.

Reference: https://bugzilla.redhat.com/show_bug.cgi?id=1057600
2014-01-24 18:32:20 +01:00

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/*
* New Interface to Process Table -- PROCTAB Stream (a la Directory streams)
* Copyright (C) 1996 Charles L. Blake.
* Copyright (C) 1998 Michael K. Johnson
* Copyright 1998-2003 Albert Cahalan
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "version.h"
#include "readproc.h"
#include "alloc.h"
#include "escape.h"
#include "pwcache.h"
#include "devname.h"
#include "procps.h"
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <stdarg.h>
#include <string.h>
#include <unistd.h>
#include <signal.h>
#include <fcntl.h>
#include <sys/dir.h>
#include <sys/types.h>
#include <sys/stat.h>
// sometimes it's easier to do this manually, w/o gcc helping
#ifdef PROF
extern void __cyg_profile_func_enter(void*,void*);
#define ENTER(x) __cyg_profile_func_enter((void*)x,(void*)x)
#define LEAVE(x) __cyg_profile_func_exit((void*)x,(void*)x)
#else
#define ENTER(x)
#define LEAVE(x)
#endif
#ifdef QUICK_THREADS
// used when multi-threaded and some memory must not be freed
#define MK_THREAD(q) q->pad_1 = '\xee'
#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
// dynamic 'utility' buffer support for file2str() calls
struct utlbuf_s {
char *buf; // dynamically grown buffer
int siz; // current len of the above
} utlbuf_s;
#ifndef SIGNAL_STRING
// convert hex string to unsigned long long
static unsigned long long unhex(const char *restrict cp){
unsigned long long ull = 0;
for(;;){
char c = *cp++;
if(unlikely(c<0x30)) break;
ull = (ull<<4) | (c - (c>0x57) ? 0x57 : 0x30) ;
}
return ull;
}
#endif
static int task_dir_missing;
// free any additional dynamically acquired storage associated with a proc_t
// ( and if it's to be reused, refresh it otherwise destroy it )
static inline void free_acquired (proc_t *p, int reuse) {
#ifdef QUICK_THREADS
if (!IS_THREAD(p)) {
#endif
if (p->environ) free((void*)*p->environ);
if (p->cmdline) free((void*)*p->cmdline);
if (p->cgroup) free((void*)*p->cgroup);
if (p->supgid) free(p->supgid);
if (p->supgrp) free(p->supgrp);
#ifdef QUICK_THREADS
}
#endif
memset(p, reuse ? '\0' : '\xff', sizeof(*p));
}
///////////////////////////////////////////////////////////////////////////
typedef struct status_table_struct {
unsigned char name[7]; // /proc/*/status field name
unsigned char len; // name length
#ifdef LABEL_OFFSET
long offset; // jump address offset
#else
void *addr;
#endif
} status_table_struct;
#ifdef LABEL_OFFSET
#define F(x) {#x, sizeof(#x)-1, (long)(&&case_##x-&&base)},
#else
#define F(x) {#x, sizeof(#x)-1, &&case_##x},
#endif
#define NUL {"", 0, 0},
// Derived from:
// gperf -7 --language=ANSI-C --key-positions=1,3,4 -C -n -c <if-not-piped>
//
// Suggested method:
// Grep this file for "case_", then strip those down to the name.
// Eliminate duplicates (due to #ifs), the ' case_' prefix and
// any c comments. Leave the colon and newline so that "Pid:\n",
// "Threads:\n", etc. would be lines, but no quote, no escape, etc.
//
// After a pipe through gperf, insert the resulting 'asso_values'
// into our 'asso' array. Then convert the gperf 'wordlist' array
// into our 'table' array by wrapping the string literals within
// the F macro and replacing empty strings with the NUL define.
//
// In the status_table_struct watch out for name size (grrr, expanding)
// and the number of entries (we mask with 63 for now). The table
// must be padded out to 64 entries, maybe 128 in the future.
static void status2proc(char *S, proc_t *restrict P, int is_proc){
long Threads = 0;
long Tgid = 0;
long Pid = 0;
// 128 entries because we trust the kernel to use ASCII names
static const unsigned char asso[] =
{
64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
64, 64, 64, 64, 64, 64, 64, 64, 28, 64,
64, 64, 64, 64, 64, 64, 8, 25, 23, 25,
6, 25, 0, 3, 64, 64, 3, 64, 25, 64,
20, 1, 1, 5, 0, 30, 0, 0, 64, 64,
64, 64, 64, 64, 64, 64, 64, 3, 64, 0,
0, 18, 64, 10, 64, 10, 64, 64, 64, 20,
64, 20, 0, 64, 25, 64, 3, 15, 64, 0,
30, 64, 64, 64, 64, 64, 64, 64
};
static const status_table_struct table[] = {
F(VmHWM)
NUL NUL
F(VmLck)
NUL
F(VmSwap)
F(VmRSS)
NUL
F(VmStk)
NUL
F(Tgid)
F(State)
NUL
F(VmLib)
NUL
F(VmSize)
F(SigQ)
NUL
F(SigIgn)
NUL
F(VmPTE)
F(FDSize)
NUL
F(SigBlk)
NUL
F(ShdPnd)
F(VmData)
NUL
F(CapInh)
NUL
F(PPid)
NUL NUL
F(CapBnd)
NUL
F(SigPnd)
NUL NUL
F(VmPeak)
NUL
F(SigCgt)
NUL NUL
F(Threads)
NUL
F(CapPrm)
NUL NUL
F(Pid)
NUL
F(CapEff)
NUL NUL
F(Gid)
NUL
F(VmExe)
NUL NUL
F(Uid)
NUL
F(Groups)
NUL NUL
F(Name)
};
#undef F
#undef NUL
ENTER(0x220);
goto base;
for(;;){
char *colon;
status_table_struct entry;
// advance to next line
S = strchr(S, '\n');
if(unlikely(!S)) break; // if no newline
S++;
// examine a field name (hash and compare)
base:
if(unlikely(!*S)) break;
entry = table[63 & (asso[(int)S[3]] + asso[(int)S[2]] + asso[(int)S[0]])];
colon = strchr(S, ':');
if(unlikely(!colon)) break;
if(unlikely(colon[1]!='\t')) break;
if(unlikely(colon-S != entry.len)) continue;
if(unlikely(memcmp(entry.name,S,colon-S))) continue;
S = colon+2; // past the '\t'
#ifdef LABEL_OFFSET
goto *(&&base + entry.offset);
#else
goto *entry.addr;
#endif
case_Name:
{ unsigned u = 0;
while(u < sizeof P->cmd - 1u){
int c = *S++;
if(unlikely(c=='\n')) break;
if(unlikely(c=='\0')) break; // should never happen
if(unlikely(c=='\\')){
c = *S++;
if(c=='\n') break; // should never happen
if(!c) break; // should never happen
if(c=='n') c='\n'; // else we assume it is '\\'
}
P->cmd[u++] = c;
}
P->cmd[u] = '\0';
S--; // put back the '\n' or '\0'
continue;
}
#ifdef SIGNAL_STRING
case_ShdPnd:
memcpy(P->signal, S, 16);
P->signal[16] = '\0';
continue;
case_SigBlk:
memcpy(P->blocked, S, 16);
P->blocked[16] = '\0';
continue;
case_SigCgt:
memcpy(P->sigcatch, S, 16);
P->sigcatch[16] = '\0';
continue;
case_SigIgn:
memcpy(P->sigignore, S, 16);
P->sigignore[16] = '\0';
continue;
case_SigPnd:
memcpy(P->_sigpnd, S, 16);
P->_sigpnd[16] = '\0';
continue;
#else
case_ShdPnd:
P->signal = unhex(S);
continue;
case_SigBlk:
P->blocked = unhex(S);
continue;
case_SigCgt:
P->sigcatch = unhex(S);
continue;
case_SigIgn:
P->sigignore = unhex(S);
continue;
case_SigPnd:
P->_sigpnd = unhex(S);
continue;
#endif
case_State:
P->state = *S;
continue;
case_Tgid:
Tgid = strtol(S,&S,10);
continue;
case_Pid:
Pid = strtol(S,&S,10);
continue;
case_PPid:
P->ppid = strtol(S,&S,10);
continue;
case_Threads:
Threads = strtol(S,&S,10);
continue;
case_Uid:
P->ruid = strtol(S,&S,10);
P->euid = strtol(S,&S,10);
P->suid = strtol(S,&S,10);
P->fuid = strtol(S,&S,10);
continue;
case_Gid:
P->rgid = strtol(S,&S,10);
P->egid = strtol(S,&S,10);
P->sgid = strtol(S,&S,10);
P->fgid = strtol(S,&S,10);
continue;
case_VmData:
P->vm_data = strtol(S,&S,10);
continue;
case_VmExe:
P->vm_exe = strtol(S,&S,10);
continue;
case_VmLck:
P->vm_lock = strtol(S,&S,10);
continue;
case_VmLib:
P->vm_lib = strtol(S,&S,10);
continue;
case_VmRSS:
P->vm_rss = strtol(S,&S,10);
continue;
case_VmSize:
P->vm_size = strtol(S,&S,10);
continue;
case_VmStk:
P->vm_stack = strtol(S,&S,10);
continue;
case_VmSwap: // Linux 2.6.34
P->vm_swap = strtol(S,&S,10);
continue;
case_Groups:
{ char *nl = strchr(S, '\n');
int j = nl ? (nl - S) : strlen(S);
if (j) {
P->supgid = xmalloc(j+1); // +1 in case space disappears
memcpy(P->supgid, S, j);
if (unlikely(' ' != P->supgid[--j])) ++j;
P->supgid[j] = '\0'; // whack the space or the newline
for ( ; j; j--)
if (' ' == P->supgid[j])
P->supgid[j] = ',';
}
continue;
}
case_CapBnd:
case_CapEff:
case_CapInh:
case_CapPrm:
case_FDSize:
case_SigQ:
case_VmHWM: // 2005, peak VmRSS unless VmRSS is bigger
case_VmPTE:
case_VmPeak: // 2005, peak VmSize unless VmSize is bigger
continue;
}
#if 0
// recent kernels supply per-tgid pending signals
if(is_proc && *ShdPnd){
memcpy(P->signal, ShdPnd, 16);
P->signal[16] = '\0';
}
#endif
// recent kernels supply per-tgid pending signals
#ifdef SIGNAL_STRING
if(!is_proc || !P->signal[0]){
memcpy(P->signal, P->_sigpnd, 16);
P->signal[16] = '\0';
}
#else
if(!is_proc){
P->signal = P->_sigpnd;
}
#endif
// Linux 2.4.13-pre1 to max 2.4.xx have a useless "Tgid"
// that is not initialized for built-in kernel tasks.
// Only 2.6.0 and above have "Threads" (nlwp) info.
if(Threads){
P->nlwp = Threads;
P->tgid = Tgid; // the POSIX PID value
P->tid = Pid; // the thread ID
}else{
P->nlwp = 1;
P->tgid = Pid;
P->tid = Pid;
}
if (!P->supgid)
P->supgid = xstrdup("-");
LEAVE(0x220);
}
static void supgrps_from_supgids (proc_t *p) {
char *g, *s;
int t;
if (!p->supgid || '-' == *p->supgid) {
p->supgrp = xstrdup("-");
return;
}
s = p->supgid;
t = 0;
do {
if (',' == *s) ++s;
g = group_from_gid((uid_t)strtol(s, &s, 10));
p->supgrp = xrealloc(p->supgrp, P_G_SZ+t+2);
t += snprintf(p->supgrp+t, P_G_SZ+2, "%s%s", t ? "," : "", g);
} while (*s);
}
///////////////////////////////////////////////////////////////////////
#ifdef OOMEM_ENABLE
static void oomscore2proc(const char* S, proc_t *restrict P)
{
sscanf(S, "%d", &P->oom_score);
}
static void oomadj2proc(const char* S, proc_t *restrict P)
{
sscanf(S, "%d", &P->oom_adj);
}
#endif
///////////////////////////////////////////////////////////////////////
static const char *ns_names[] = {
[IPCNS] = "ipc",
[MNTNS] = "mnt",
[NETNS] = "net",
[PIDNS] = "pid",
[USERNS] = "user",
[UTSNS] = "uts",
};
const char *get_ns_name(int id) {
if (id >= NUM_NS)
return NULL;
return ns_names[id];
}
int get_ns_id(const char *name) {
int i;
for (i = 0; i < NUM_NS; i++)
if (!strcmp(ns_names[i], name))
return i;
return -1;
}
static void ns2proc(const char *directory, proc_t *restrict p) {
char path[PROCPATHLEN];
struct stat sb;
int i;
for (i = 0; i < NUM_NS; i++) {
snprintf(path, sizeof(path), "%s/ns/%s", directory, ns_names[i]);
if (0 == stat(path, &sb))
p->ns[i] = (long)sb.st_ino;
#if 0
else // this allows a caller to distinguish
p->ns[i] = -errno; // between the ENOENT or EACCES errors
#endif
}
}
///////////////////////////////////////////////////////////////////////
// Reads /proc/*/stat files, being careful not to trip over processes with
// names like ":-) 1 2 3 4 5 6".
static void stat2proc(const char* S, proc_t *restrict P) {
unsigned num;
char* tmp;
ENTER(0x160);
/* fill in default values for older kernels */
P->processor = 0;
P->rtprio = -1;
P->sched = -1;
P->nlwp = 0;
S = strchr(S, '(') + 1;
tmp = strrchr(S, ')');
num = tmp - S;
if(unlikely(num >= sizeof P->cmd)) num = sizeof P->cmd - 1;
memcpy(P->cmd, S, num);
P->cmd[num] = '\0';
S = tmp + 2; // skip ") "
num = sscanf(S,
"%c "
"%d %d %d %d %d "
"%lu %lu %lu %lu %lu "
"%Lu %Lu %Lu %Lu " /* utime stime cutime cstime */
"%ld %ld "
"%d "
"%ld "
"%Lu " /* start_time */
"%lu "
"%ld "
"%lu %"KLF"u %"KLF"u %"KLF"u %"KLF"u %"KLF"u "
"%*s %*s %*s %*s " /* discard, no RT signals & Linux 2.1 used hex */
"%"KLF"u %*u %*u "
"%d %d "
"%lu %lu",
&P->state,
&P->ppid, &P->pgrp, &P->session, &P->tty, &P->tpgid,
&P->flags, &P->min_flt, &P->cmin_flt, &P->maj_flt, &P->cmaj_flt,
&P->utime, &P->stime, &P->cutime, &P->cstime,
&P->priority, &P->nice,
&P->nlwp,
&P->alarm,
&P->start_time,
&P->vsize,
&P->rss,
&P->rss_rlim, &P->start_code, &P->end_code, &P->start_stack, &P->kstk_esp, &P->kstk_eip,
/* P->signal, P->blocked, P->sigignore, P->sigcatch, */ /* can't use */
&P->wchan, /* &P->nswap, &P->cnswap, */ /* nswap and cnswap dead for 2.4.xx and up */
/* -- Linux 2.0.35 ends here -- */
&P->exit_signal, &P->processor, /* 2.2.1 ends with "exit_signal" */
/* -- Linux 2.2.8 to 2.5.17 end here -- */
&P->rtprio, &P->sched /* both added to 2.5.18 */
);
if(!P->nlwp){
P->nlwp = 1;
}
LEAVE(0x160);
}
/////////////////////////////////////////////////////////////////////////
static void statm2proc(const char* s, proc_t *restrict P) {
int num;
num = sscanf(s, "%ld %ld %ld %ld %ld %ld %ld",
&P->size, &P->resident, &P->share,
&P->trs, &P->lrs, &P->drs, &P->dt);
/* fprintf(stderr, "statm2proc converted %d fields.\n",num); */
}
static int file2str(const char *directory, const char *what, struct utlbuf_s *ub) {
#define buffGRW 1024
char path[PROCPATHLEN];
int fd, num, tot_read = 0;
/* on first use we preallocate a buffer of minimum size to emulate
former 'local static' behavior -- even if this read fails, that
buffer will likely soon be used for another subdirectory anyway
( besides, with this xcalloc we will never need to use memcpy ) */
if (ub->buf) ub->buf[0] = '\0';
else ub->buf = xcalloc((ub->siz = buffGRW));
sprintf(path, "%s/%s", directory, what);
if (-1 == (fd = open(path, O_RDONLY, 0))) return -1;
while (0 < (num = read(fd, ub->buf + tot_read, ub->siz - tot_read))) {
tot_read += num;
if (tot_read < ub->siz) break;
ub->buf = xrealloc(ub->buf, (ub->siz += buffGRW));
};
ub->buf[tot_read] = '\0';
close(fd);
if (unlikely(tot_read < 1)) return -1;
return tot_read;
#undef buffGRW
}
static char** file2strvec(const char* directory, const char* what) {
char buf[2048]; /* read buf bytes at a time */
char *p, *rbuf = 0, *endbuf, **q, **ret;
int fd, tot = 0, n, c, end_of_file = 0;
int align;
sprintf(buf, "%s/%s", directory, what);
fd = open(buf, O_RDONLY, 0);
if(fd==-1) return NULL;
/* read whole file into a memory buffer, allocating as we go */
while ((n = read(fd, buf, sizeof buf - 1)) >= 0) {
if (n < (int)(sizeof buf - 1))
end_of_file = 1;
if (n == 0 && rbuf == 0) {
close(fd);
return NULL; /* process died between our open and read */
}
if (n < 0) {
if (rbuf)
free(rbuf);
close(fd);
return NULL; /* read error */
}
if (end_of_file && (n == 0 || buf[n-1]))/* last read char not null */
buf[n++] = '\0'; /* so append null-terminator */
rbuf = xrealloc(rbuf, tot + n); /* allocate more memory */
memcpy(rbuf + tot, buf, n); /* copy buffer into it */
tot += n; /* increment total byte ctr */
if (end_of_file)
break;
}
close(fd);
if (n <= 0 && !end_of_file) {
if (rbuf) free(rbuf);
return NULL; /* read error */
}
endbuf = rbuf + tot; /* count space for pointers */
align = (sizeof(char*)-1) - ((tot + sizeof(char*)-1) & (sizeof(char*)-1));
for (c = 0, p = rbuf; p < endbuf; p++) {
if (!*p || *p == '\n')
c += sizeof(char*);
if (*p == '\n')
*p = 0;
}
c += sizeof(char*); /* one extra for NULL term */
rbuf = xrealloc(rbuf, tot + c + align); /* make room for ptrs AT END */
endbuf = rbuf + tot; /* addr just past data buf */
q = ret = (char**) (endbuf+align); /* ==> free(*ret) to dealloc */
*q++ = p = rbuf; /* point ptrs to the strings */
endbuf--; /* do not traverse final NUL */
while (++p < endbuf)
if (!*p) /* NUL char implies that */
*q++ = p+1; /* next string -> next char */
*q = 0; /* null ptr list terminator */
return ret;
}
// this is the former under utilized 'read_cmdline', which has been
// generalized in support of these new libproc flags:
// PROC_EDITCGRPCVT, PROC_EDITCMDLCVT and PROC_EDITENVRCVT
static int read_unvectored(char *restrict const dst, unsigned sz, const char* whom, const char *what, char sep) {
char path[PROCPATHLEN];
int fd;
unsigned n = 0;
snprintf(path, sizeof(path), "%s/%s", whom, what);
fd = open(path, O_RDONLY);
if(fd==-1) return 0;
for(;;){
ssize_t r = read(fd,dst+n,sz-n);
if(r==-1){
if(errno==EINTR) continue;
break;
}
n += r;
if(n==sz) { // filled the buffer
--n; // make room for '\0'
break;
}
if(r==0) break; // EOF
}
close(fd);
if(n){
int i=n;
while(i && dst[i-1]=='\0') --i; // skip trailing zeroes
while(i--)
if(dst[i]=='\n' || dst[i]=='\0') dst[i]=sep;
if(dst[n-1]==' ') dst[n-1]='\0';
}
dst[n] = '\0';
return n;
}
static char** vectorize_this_str (const char* src) {
#define pSZ (sizeof(char*))
char *cpy, **vec;
int adj, tot;
tot = strlen(src) + 1; // prep for our vectors
adj = (pSZ-1) - ((tot + pSZ-1) & (pSZ-1)); // calc alignment bytes
cpy = xcalloc(tot + adj + (2 * pSZ)); // get new larger buffer
snprintf(cpy, tot, "%s", src); // duplicate their string
vec = (char**)(cpy + tot + adj); // prep pointer to pointers
*vec = cpy; // point 1st vector to string
*(vec+1) = NULL; // null ptr 'list' delimit
return vec; // ==> free(*vec) to dealloc
#undef pSZ
}
// This routine reads a 'cgroup' for the designated proc_t.
// It is similar to file2strvec except we filter and concatenate
// the data into a single string represented as a single vector.
static void fill_cgroup_cvt (const char* directory, proc_t *restrict p) {
#define vMAX ( MAX_BUFSZ - (int)(dst - dst_buffer) )
char *src, *dst, *grp, *eob;
int tot, x, whackable_int = MAX_BUFSZ;
*(dst = dst_buffer) = '\0'; // empty destination
tot = read_unvectored(src_buffer, MAX_BUFSZ, directory, "cgroup", '\0');
for (src = src_buffer, eob = src_buffer + tot; src < eob; src += x) {
x = 1; // loop assist
if (!*src) continue;
x = strlen((grp = src));
if ('/' == grp[x - 1]) continue; // skip empty root cgroups
#if 0
grp += strspn(grp, "0123456789:"); // jump past group number
#endif
dst += snprintf(dst, vMAX, "%s", (dst > dst_buffer) ? "," : "");
dst += escape_str(dst, grp, vMAX, &whackable_int);
}
p->cgroup = vectorize_this_str(dst_buffer[0] ? dst_buffer : "-");
#undef vMAX
}
// This routine reads a 'cmdline' for the designated proc_t, "escapes"
// the result into a single string represented as a single vector
// 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 )
int whackable_int = MAX_BUFSZ;
if (read_unvectored(src_buffer, MAX_BUFSZ, directory, "cmdline", ' '))
escape_str(dst_buffer, src_buffer, MAX_BUFSZ, &whackable_int);
else
escape_command(dst_buffer, p, MAX_BUFSZ, &whackable_int, uFLG);
p->cmdline = vectorize_this_str(dst_buffer);
#undef uFLG
}
// This routine reads an 'environ' for the designated proc_t and
// guarantees the caller a valid proc_t.environ pointer.
static void fill_environ_cvt (const char* directory, proc_t *restrict p) {
int whackable_int = MAX_BUFSZ;
dst_buffer[0] = '\0';
if (read_unvectored(src_buffer, MAX_BUFSZ, directory, "environ", ' '))
escape_str(dst_buffer, src_buffer, MAX_BUFSZ, &whackable_int);
p->environ = vectorize_this_str(dst_buffer[0] ? dst_buffer : "-");
}
// warning: interface may change
int read_cmdline(char *restrict const dst, unsigned sz, unsigned pid) {
char path[PROCPATHLEN];
snprintf(path, sizeof(path), "/proc/%u", pid);
return read_unvectored(dst, sz, path, "cmdline", ' ');
}
/* These are some nice GNU C expression subscope "inline" functions.
* The can be used with arbitrary types and evaluate their arguments
* exactly once.
*/
/* Test if item X of type T is present in the 0 terminated list L */
# define XinL(T, X, L) ( { \
T x = (X), *l = (L); \
while (*l && *l != x) l++; \
*l == x; \
} )
/* Test if item X of type T is present in the list L of length N */
# define XinLN(T, X, L, N) ( { \
T x = (X), *l = (L); \
int i = 0, n = (N); \
while (i < n && l[i] != x) i++; \
i < n && l[i] == x; \
} )
//////////////////////////////////////////////////////////////////////////////////
// This reads process info from /proc in the traditional way, for one process.
// The pid (tgid? tid?) is already in p, and a path to it in path, with some
// room to spare.
static proc_t* simple_readproc(PROCTAB *restrict const PT, proc_t *restrict const p) {
static struct utlbuf_s ub = { NULL, 0 }; // buf for stat,statm,status
static struct stat sb; // stat() buffer
char *restrict const path = PT->path;
unsigned flags = PT->flags;
if (unlikely(stat(path, &sb) == -1)) /* no such dirent (anymore) */
goto next_proc;
if ((flags & PROC_UID) && !XinLN(uid_t, sb.st_uid, PT->uids, PT->nuid))
goto next_proc; /* not one of the requested uids */
p->euid = sb.st_uid; /* need a way to get real uid */
p->egid = sb.st_gid; /* need a way to get real gid */
if (flags & PROC_FILLSTAT) { // read /proc/#/stat
if (unlikely(file2str(path, "stat", &ub) == -1))
goto next_proc;
stat2proc(ub.buf, p);
}
if (flags & PROC_FILLMEM) { // read /proc/#/statm
if (likely(file2str(path, "statm", &ub) != -1))
statm2proc(ub.buf, p);
}
if (flags & PROC_FILLSTATUS) { // read /proc/#/status
if (likely(file2str(path, "status", &ub) != -1)){
status2proc(ub.buf, p, 1);
if (flags & PROC_FILLSUPGRP)
supgrps_from_supgids(p);
}
}
// if multithreaded, some values are crap
if(p->nlwp > 1){
p->wchan = (KLONG)~0ull;
}
/* some number->text resolving which is time consuming */
if (flags & PROC_FILLUSR){
memcpy(p->euser, user_from_uid(p->euid), sizeof p->euser);
if(flags & PROC_FILLSTATUS) {
memcpy(p->ruser, user_from_uid(p->ruid), sizeof p->ruser);
memcpy(p->suser, user_from_uid(p->suid), sizeof p->suser);
memcpy(p->fuser, user_from_uid(p->fuid), sizeof p->fuser);
}
}
/* some number->text resolving which is time consuming */
if (flags & PROC_FILLGRP){
memcpy(p->egroup, group_from_gid(p->egid), sizeof p->egroup);
if(flags & PROC_FILLSTATUS) {
memcpy(p->rgroup, group_from_gid(p->rgid), sizeof p->rgroup);
memcpy(p->sgroup, group_from_gid(p->sgid), sizeof p->sgroup);
memcpy(p->fgroup, group_from_gid(p->fgid), sizeof p->fgroup);
}
}
if (unlikely(flags & PROC_FILLENV)) { // read /proc/#/environ
if (flags & PROC_EDITENVRCVT)
fill_environ_cvt(path, p);
else
p->environ = file2strvec(path, "environ");
} else
p->environ = NULL;
if (flags & (PROC_FILLCOM|PROC_FILLARG)) { // read /proc/#/cmdline
if (flags & PROC_EDITCMDLCVT)
fill_cmdline_cvt(path, p);
else
p->cmdline = file2strvec(path, "cmdline");
} else
p->cmdline = NULL;
if ((flags & PROC_FILLCGROUP)) { // read /proc/#/cgroup
if (flags & PROC_EDITCGRPCVT)
fill_cgroup_cvt(path, p);
else
p->cgroup = file2strvec(path, "cgroup");
} else
p->cgroup = NULL;
#ifdef OOMEM_ENABLE
if (unlikely(flags & PROC_FILLOOM)) {
if (likely(file2str(path, "oom_score", &ub) != -1))
oomscore2proc(ub.buf, p);
if (likely(file2str(path, "oom_adj", &ub) != -1))
oomadj2proc(ub.buf, p);
}
#endif
if (unlikely(flags & PROC_FILLNS)) // read /proc/#/ns/*
ns2proc(path, p);
return p;
next_proc:
return NULL;
}
//////////////////////////////////////////////////////////////////////////////////
// This reads /proc/*/task/* data, for one task.
#ifdef QUICK_THREADS
// p is the POSIX process (task group summary) & source for some copies if !NULL
#else
// p is the POSIX process (task group summary) (not needed by THIS implementation)
#endif
// t is the POSIX thread (task group member, generally not the leader)
// path is a path to the task, with some room to spare.
static proc_t* simple_readtask(PROCTAB *restrict const PT, const proc_t *restrict const p, proc_t *restrict const t, char *restrict const path) {
static struct utlbuf_s ub = { NULL, 0 }; // buf for stat,statm,status
static struct stat sb; // stat() buffer
unsigned flags = PT->flags;
if (unlikely(stat(path, &sb) == -1)) /* no such dirent (anymore) */
goto next_task;
// if ((flags & PROC_UID) && !XinLN(uid_t, sb.st_uid, PT->uids, PT->nuid))
// goto next_task; /* not one of the requested uids */
t->euid = sb.st_uid; /* need a way to get real uid */
t->egid = sb.st_gid; /* need a way to get real gid */
if (flags & PROC_FILLSTAT) { // read /proc/#/task/#/stat
if (unlikely(file2str(path, "stat", &ub) == -1))
goto next_task;
stat2proc(ub.buf, t);
}
#ifndef QUICK_THREADS
if (flags & PROC_FILLMEM) // read /proc/#/task/#statm
if (likely(file2str(path, "statm", &ub) != -1))
statm2proc(ub.buf, t);
#endif
if (flags & PROC_FILLSTATUS) { // read /proc/#/task/#/status
if (likely(file2str(path, "status", &ub) != -1)) {
status2proc(ub.buf, t, 0);
#ifndef QUICK_THREADS
if (flags & PROC_FILLSUPGRP)
supgrps_from_supgids(t);
#endif
}
}
/* some number->text resolving which is time consuming */
if (flags & PROC_FILLUSR){
memcpy(t->euser, user_from_uid(t->euid), sizeof t->euser);
if(flags & PROC_FILLSTATUS) {
memcpy(t->ruser, user_from_uid(t->ruid), sizeof t->ruser);
memcpy(t->suser, user_from_uid(t->suid), sizeof t->suser);
memcpy(t->fuser, user_from_uid(t->fuid), sizeof t->fuser);
}
}
/* some number->text resolving which is time consuming */
if (flags & PROC_FILLGRP){
memcpy(t->egroup, group_from_gid(t->egid), sizeof t->egroup);
if(flags & PROC_FILLSTATUS) {
memcpy(t->rgroup, group_from_gid(t->rgid), sizeof t->rgroup);
memcpy(t->sgroup, group_from_gid(t->sgid), sizeof t->sgroup);
memcpy(t->fgroup, group_from_gid(t->fgid), sizeof t->fgroup);
}
}
#ifdef QUICK_THREADS
if (!p) {
if (flags & PROC_FILLMEM)
if (likely(file2str(path, "statm", &ub) != -1))
statm2proc(ub.buf, t);
if (flags & PROC_FILLSUPGRP)
supgrps_from_supgids(t);
#endif
if (unlikely(flags & PROC_FILLENV)) { // read /proc/#/task/#/environ
if (flags & PROC_EDITENVRCVT)
fill_environ_cvt(path, t);
else
t->environ = file2strvec(path, "environ");
} else
t->environ = NULL;
if (flags & (PROC_FILLCOM|PROC_FILLARG)) { // read /proc/#/task/#/cmdline
if (flags & PROC_EDITCMDLCVT)
fill_cmdline_cvt(path, t);
else
t->cmdline = file2strvec(path, "cmdline");
} else
t->cmdline = NULL;
if ((flags & PROC_FILLCGROUP)) { // read /proc/#/task/#/cgroup
if (flags & PROC_EDITCGRPCVT)
fill_cgroup_cvt(path, t);
else
t->cgroup = file2strvec(path, "cgroup");
} else
t->cgroup = NULL;
#ifdef QUICK_THREADS
} else {
t->size = p->size;
t->resident = p->resident;
t->share = p->share;
t->trs = p->trs;
t->lrs = p->lrs;
t->drs = p->drs;
t->dt = p->dt;
t->cmdline = p->cmdline; // better not free these until done with all threads!
t->environ = p->environ;
t->cgroup = p->cgroup;
if (t->supgid) free(t->supgid);
t->supgid = p->supgid;
t->supgrp = p->supgrp;
MK_THREAD(t);
}
#endif
#ifdef OOMEM_ENABLE
if (unlikely(flags & PROC_FILLOOM)) {
if (likely(file2str(path, "oom_score", &ub) != -1))
oomscore2proc(ub.buf, t);
if (likely(file2str(path, "oom_adj", &ub) != -1))
oomadj2proc(ub.buf, t);
}
#endif
if (unlikely(flags & PROC_FILLNS)) // read /proc/#/task/#/ns/*
ns2proc(path, t);
return t;
next_task:
return NULL;
#ifndef QUICK_THREADS
(void)p;
#endif
}
//////////////////////////////////////////////////////////////////////////////////
// This finds processes in /proc in the traditional way.
// Return non-zero on success.
static int simple_nextpid(PROCTAB *restrict const PT, proc_t *restrict const p) {
static struct direct *ent; /* dirent handle */
char *restrict const path = PT->path;
for (;;) {
ent = readdir(PT->procfs);
if(unlikely(unlikely(!ent) || unlikely(!ent->d_name))) return 0;
if(likely(likely(*ent->d_name > '0') && likely(*ent->d_name <= '9'))) break;
}
p->tgid = strtoul(ent->d_name, NULL, 10);
p->tid = p->tgid;
memcpy(path, "/proc/", 6);
strcpy(path+6, ent->d_name); // trust /proc to not contain evil top-level entries
return 1;
}
//////////////////////////////////////////////////////////////////////////////////
// This finds tasks in /proc/*/task/ in the traditional way.
// Return non-zero on success.
static int simple_nexttid(PROCTAB *restrict const PT, const proc_t *restrict const p, proc_t *restrict const t, char *restrict const path) {
static struct direct *ent; /* dirent handle */
if(PT->taskdir_user != p->tgid){
if(PT->taskdir){
closedir(PT->taskdir);
}
// use "path" as some tmp space
snprintf(path, PROCPATHLEN, "/proc/%d/task", p->tgid);
PT->taskdir = opendir(path);
if(!PT->taskdir) return 0;
PT->taskdir_user = p->tgid;
}
for (;;) {
ent = readdir(PT->taskdir);
if(unlikely(unlikely(!ent) || unlikely(!ent->d_name))) return 0;
if(likely(likely(*ent->d_name > '0') && likely(*ent->d_name <= '9'))) break;
}
t->tid = strtoul(ent->d_name, NULL, 10);
t->tgid = p->tgid;
//t->ppid = p->ppid; // cover for kernel behavior? we want both actually...?
snprintf(path, PROCPATHLEN, "/proc/%d/task/%s", p->tgid, ent->d_name);
return 1;
}
//////////////////////////////////////////////////////////////////////////////////
// This "finds" processes in a list that was given to openproc().
// Return non-zero on success. (tgid was handy)
static int listed_nextpid(PROCTAB *restrict const PT, proc_t *restrict const p) {
char *restrict const path = PT->path;
pid_t tgid = *(PT->pids)++;
if(likely(tgid)){
snprintf(path, PROCPATHLEN, "/proc/%d", tgid);
p->tgid = tgid;
p->tid = tgid; // they match for leaders
}
return tgid;
}
//////////////////////////////////////////////////////////////////////////////////
/* readproc: return a pointer to a proc_t filled with requested info about the
* next process available matching the restriction set. If no more such
* processes are available, return a null pointer (boolean false). Use the
* passed buffer instead of allocating space if it is non-NULL. */
/* This is optimized so that if a PID list is given, only those files are
* searched for in /proc. If other lists are given in addition to the PID list,
* the same logic can follow through as for the no-PID list case. This is
* fairly complex, but it does try to not to do any unnecessary work.
*/
proc_t* readproc(PROCTAB *restrict const PT, proc_t *restrict p) {
proc_t *ret;
proc_t *saved_p;
PT->did_fake=0;
// if (PT->taskdir) {
// closedir(PT->taskdir);
// PT->taskdir = NULL;
// PT->taskdir_user = -1;
// }
saved_p = p;
if(!p) p = xcalloc(sizeof *p);
else free_acquired(p, 1);
for(;;){
// fills in the path, plus p->tid and p->tgid
if (unlikely(!PT->finder(PT,p))) goto out;
// go read the process data
ret = PT->reader(PT,p);
if(ret) return ret;
}
out:
if(!saved_p) free(p);
// FIXME: maybe set tid to -1 here, for "-" in display?
return NULL;
}
//////////////////////////////////////////////////////////////////////////////////
// readtask: return a pointer to a proc_t filled with requested info about the
// next task available. If no more such tasks are available, return a null
// pointer (boolean false). Use the passed buffer instead of allocating
// space if it is non-NULL.
proc_t* readtask(PROCTAB *restrict const PT, const proc_t *restrict const p, proc_t *restrict t) {
char path[PROCPATHLEN]; // must hold /proc/2000222000/task/2000222000/cmdline
proc_t *ret;
proc_t *saved_t;
saved_t = t;
if(!t) t = xcalloc(sizeof *t);
else free_acquired(t, 1);
// 1. got to fake a thread for old kernels
#ifdef QUICK_THREADS
// 2. for single-threaded processes, this is faster (but must patch up stuff that differs!)
if(task_dir_missing || p->nlwp < 2){
#else
if(task_dir_missing){
#endif
if(PT->did_fake) goto out;
PT->did_fake=1;
memcpy(t,p,sizeof(proc_t));
// use the per-task pending, not per-tgid pending
#ifdef SIGNAL_STRING
memcpy(&t->signal, &t->_sigpnd, sizeof t->signal);
#else
t->signal = t->_sigpnd;
#endif
#ifdef QUICK_THREADS
MK_THREAD(t);
#else
t->environ = NULL;
t->cmdline = vectorize_this_str("n/a");
t->cgroup = NULL;
t->supgid = NULL;
t->supgrp = NULL;
#endif
return t;
}
for(;;){
// fills in the path, plus t->tid and t->tgid
if (unlikely(!PT->taskfinder(PT,p,t,path))) goto out; // simple_nexttid
// go read the task data
ret = PT->taskreader(PT,p,t,path); // simple_readtask
if(ret) return ret;
}
out:
if(!saved_t) free(t);
return NULL;
}
//////////////////////////////////////////////////////////////////////////////////
// readeither: return a pointer to a proc_t filled with requested info about
// the next unique process or task available. If no more are available,
// return a null pointer (boolean false). Use the passed buffer instead
// of allocating space if it is non-NULL.
proc_t* readeither (PROCTAB *restrict const PT, proc_t *restrict x) {
static proc_t skel_p; // skeleton proc_t, only uses tid + tgid
static proc_t *new_p; // for process/task transitions
char path[PROCPATHLEN];
proc_t *saved_x, *ret;
saved_x = x;
if (!x) x = xcalloc(sizeof(*x));
else free_acquired(x,1);
if (new_p) goto next_task;
next_proc:
new_p = NULL;
for (;;) {
// fills in the PT->path, plus skel_p.tid and skel_p.tgid
if (!PT->finder(PT,&skel_p)) goto end_procs; // simple_nextpid
if (!task_dir_missing) break;
if ((ret = PT->reader(PT,x))) return ret; // simple_readproc
}
next_task:
// fills in our path, plus x->tid and x->tgid
if ((!(PT->taskfinder(PT,&skel_p,x,path))) // simple_nexttid
|| (!(ret = PT->taskreader(PT,new_p,x,path)))) { // simple_readtask
goto next_proc;
}
if (!new_p) new_p = ret;
return ret;
end_procs:
if (!saved_x) free(x);
return NULL;
}
//////////////////////////////////////////////////////////////////////////////////
// initiate a process table scan
PROCTAB* openproc(int flags, ...) {
va_list ap;
struct stat sbuf;
static int did_stat;
PROCTAB* PT = xmalloc(sizeof(PROCTAB));
if (!did_stat){
task_dir_missing = stat("/proc/self/task", &sbuf);
did_stat = 1;
}
PT->taskdir = NULL;
PT->taskdir_user = -1;
PT->taskfinder = simple_nexttid;
PT->taskreader = simple_readtask;
PT->reader = simple_readproc;
if (flags & PROC_PID){
PT->procfs = NULL;
PT->finder = listed_nextpid;
}else{
PT->procfs = opendir("/proc");
if (!PT->procfs) { free(PT); return NULL; }
PT->finder = simple_nextpid;
}
PT->flags = flags;
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);
if (!src_buffer){
src_buffer = xmalloc(MAX_BUFSZ);
dst_buffer = xmalloc(MAX_BUFSZ);
}
return PT;
}
// terminate a process table scan
void closeproc(PROCTAB* PT) {
if (PT){
if (PT->procfs) closedir(PT->procfs);
if (PT->taskdir) closedir(PT->taskdir);
memset(PT,'#',sizeof(PROCTAB));
free(PT);
}
}
// deallocate space allocated by readproc
void freeproc(proc_t* p) {
if (p) {
free_acquired(p, 0);
free(p);
}
}
//////////////////////////////////////////////////////////////////////////////////
void look_up_our_self(proc_t *p) {
struct utlbuf_s ub = { NULL, 0 };
if(file2str("/proc/self", "stat", &ub) == -1){
fprintf(stderr, "Error, do this: mount -t proc proc /proc\n");
_exit(47);
}
stat2proc(ub.buf, p); // parse /proc/self/stat
free(ub.buf);
}
HIDDEN_ALIAS(readproc);
HIDDEN_ALIAS(readtask);
HIDDEN_ALIAS(readeither);
/* Convenient wrapper around openproc and readproc to slurp in the whole process
* table subset satisfying the constraints of flags and the optional PID list.
* Free allocated memory with exit(). Access via tab[N]->member. The pointer
* list is NULL terminated.
*/
proc_t** readproctab(int flags, ...) {
PROCTAB* PT = NULL;
proc_t** tab = NULL;
int n = 0;
va_list ap;
va_start(ap, flags); /* pass through args to openproc */
if (flags & PROC_UID) {
/* temporary variables to ensure that va_arg() instances
* are called in the right order
*/
uid_t* u;
int i;
u = va_arg(ap, uid_t*);
i = va_arg(ap, int);
PT = openproc(flags, u, i);
}
else if (flags & PROC_PID)
PT = openproc(flags, va_arg(ap, void*)); /* assume ptr sizes same */
else
PT = openproc(flags);
va_end(ap);
if (!PT)
return 0;
do { /* read table: */
tab = xrealloc(tab, (n+1)*sizeof(proc_t*));/* realloc as we go, using */
tab[n] = readproc_direct(PT, NULL); /* final null to terminate */
} while (tab[n++]); /* stop when NULL reached */
closeproc(PT);
return tab;
}
// Try again, this time with threads and selection.
proc_data_t *readproctab2(int(*want_proc)(proc_t *buf), int(*want_task)(proc_t *buf), PROCTAB *restrict const PT) {
static proc_data_t pd;
proc_t** ptab = NULL;
unsigned n_proc_alloc = 0;
unsigned n_proc = 0;
proc_t** ttab = NULL;
unsigned n_task_alloc = 0;
unsigned n_task = 0;
proc_t* data = NULL;
unsigned n_alloc = 0;
unsigned long n_used = 0;
for(;;){
proc_t *tmp;
if(n_alloc == n_used){
//proc_t *old = data;
n_alloc = n_alloc*5/4+30; // grow by over 25%
data = xrealloc(data,sizeof(proc_t)*n_alloc);
memset(data+n_used, 0, sizeof(proc_t)*(n_alloc-n_used));
}
if(n_proc_alloc == n_proc){
//proc_t **old = ptab;
n_proc_alloc = n_proc_alloc*5/4+30; // grow by over 25%
ptab = xrealloc(ptab,sizeof(proc_t*)*n_proc_alloc);
}
tmp = readproc_direct(PT, data+n_used);
if(!tmp) break;
if(!want_proc(tmp)) continue;
ptab[n_proc++] = (proc_t*)(n_used++);
if(!( PT->flags & PROC_LOOSE_TASKS )) continue;
for(;;){
proc_t *t;
if(n_alloc == n_used){
proc_t *old = data;
n_alloc = n_alloc*5/4+30; // grow by over 25%
data = xrealloc(data,sizeof(proc_t)*n_alloc);
// have to move tmp too
tmp = data+(tmp-old);
memset(data+n_used+1, 0, sizeof(proc_t)*(n_alloc-(n_used+1)));
}
if(n_task_alloc == n_task){
//proc_t **old = ttab;
n_task_alloc = n_task_alloc*5/4+1; // grow by over 25%
ttab = xrealloc(ttab,sizeof(proc_t*)*n_task_alloc);
}
t = readtask_direct(PT, tmp, data+n_used);
if(!t) break;
if(!want_task(t)) continue;
ttab[n_task++] = (proc_t*)(n_used++);
}
}
pd.proc = ptab;
pd.task = ttab;
pd.nproc = n_proc;
pd.ntask = n_task;
if(PT->flags & PROC_LOOSE_TASKS){
pd.tab = ttab;
pd.n = n_task;
}else{
pd.tab = ptab;
pd.n = n_proc;
}
// change array indexes to pointers
while(n_proc--) ptab[n_proc] = data+(long)(ptab[n_proc]);
while(n_task--) ttab[n_task] = data+(long)(ttab[n_task]);
return &pd;
}
// Try try yet again, this time treating processes and threads the same...
proc_data_t *readproctab3 (int(*want_task)(proc_t *buf), PROCTAB *restrict const PT) {
static proc_data_t pd;
proc_t **tab = NULL;
unsigned n_alloc = 0;
unsigned n_used = 0;
proc_t *p = NULL;
for (;;) {
if (n_alloc == n_used) {
n_alloc = n_alloc*5/4+30; // grow by over 25%
tab = xrealloc(tab,sizeof(proc_t*)*n_alloc);
}
// let this next guy allocate the necessary proc_t storage
// (or recycle it) since he can't tolerate realloc relocations
if (!(p = readeither_direct(PT,p))) break;
if (want_task(p)) {
tab[n_used++] = p;
p = NULL;
}
}
pd.tab = tab;
pd.n = n_used;
return &pd;
}
/*
* get_proc_stats - lookup a single tasks information and fill out a proc_t
*
* On failure, returns NULL. On success, returns 'p' and 'p' is a valid
* and filled out proc_t structure.
*/
proc_t * get_proc_stats(pid_t pid, proc_t *p) {
struct utlbuf_s ub = { NULL, 0 };
static char path[32];
struct stat statbuf;
sprintf(path, "/proc/%d", pid);
if (stat(path, &statbuf)) {
perror("stat");
return NULL;
}
if (file2str(path, "stat", &ub) >= 0)
stat2proc(ub.buf, p);
if (file2str(path, "statm", &ub) >= 0)
statm2proc(ub.buf, p);
if (file2str(path, "status", &ub) >= 0)
status2proc(ub.buf, p, 0);
free(ub.buf);
return p;
}
#undef MK_THREAD
#undef IS_THREAD
#undef MAX_BUFSZ
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