Add compat mode for systems without openat(2)

This commit is contained in:
Christian Göttsche 2020-11-20 17:50:34 +01:00 committed by BenBE
parent 638207a2ff
commit 2ff2859c23
5 changed files with 111 additions and 42 deletions

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@ -13,6 +13,11 @@ jobs:
run: ./autogen.sh
- name: Configure
run: ./configure --enable-werror --enable-linux-affinity --disable-unicode --disable-sensors
- name: Enable compatibility modes
run: |
sed -i 's/#define HAVE_FSTATAT 1/#undef HAVE_FSTATAT/g' config.h
sed -i 's/#define HAVE_OPENAT 1/#undef HAVE_OPENAT/g' config.h
sed -i 's/#define HAVE_READLINKAT 1/#undef HAVE_READLINKAT/g' config.h
- name: Build
run: make -k
- name: Distcheck

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@ -80,6 +80,20 @@ int Compat_fstatat(int dirfd,
#endif
}
#ifndef HAVE_OPENAT
int Compat_openat(const char* dirpath,
const char* pathname,
int flags) {
char path[4096];
xSnprintf(path, sizeof(path), "%s/%s", dirpath, pathname);
return open(path, flags);
}
#endif /* !HAVE_OPENAT */
int Compat_readlinkat(int dirfd,
const char* dirpath,
const char* pathname,

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@ -7,7 +7,11 @@ Released under the GNU GPLv2, see the COPYING file
in the source distribution for its full text.
*/
#include "config.h" // IWYU pragma: keep
#include <fcntl.h>
#include <stddef.h>
#include <unistd.h>
#include <sys/stat.h>
@ -22,6 +26,30 @@ int Compat_fstatat(int dirfd,
struct stat* statbuf,
int flags);
#ifdef HAVE_OPENAT
typedef int openat_arg_t;
static inline void Compat_openatArgClose(openat_arg_t dirfd) {
close(dirfd);
}
static inline int Compat_openat(openat_arg_t dirfd, const char* pathname, int flags) {
return openat(dirfd, pathname, flags);
}
#else /* HAVE_OPENAT */
typedef const char* openat_arg_t;
static inline void Compat_openatArgClose(openat_arg_t dirpath) {
(void)dirpath;
}
int Compat_openat(openat_arg_t dirpath, const char* pathname, int flags);
#endif /* HAVE_OPENAT */
int Compat_readlinkat(int dirfd,
const char* dirpath,
const char* pathname,

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@ -92,7 +92,7 @@ AC_TYPE_UINT64_T
# ----------------------------------------------------------------------
AC_FUNC_CLOSEDIR_VOID
AC_FUNC_STAT
AC_CHECK_FUNCS([faccessat fstatat memmove readlinkat strdup strncasecmp strstr])
AC_CHECK_FUNCS([faccessat fstatat memmove openat readlinkat strdup strncasecmp strstr])
AC_SEARCH_LIBS([dlopen], [dl dld])

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@ -38,8 +38,8 @@ in the source distribution for its full text.
#include <netlink/genl/ctrl.h>
#endif
#include "CRT.h"
#include "Compat.h"
#include "CRT.h"
#include "LinuxProcess.h"
#include "Macros.h"
#include "Object.h"
@ -81,10 +81,10 @@ static ssize_t xread(int fd, void* buf, size_t count) {
}
}
static FILE* fopenat(int dirfd, const char* pathname, const char* mode) {
static FILE* fopenat(openat_arg_t openatArg, const char* pathname, const char* mode) {
assert(String_eq(mode, "r")); /* only currently supported mode */
int fd = openat(dirfd, pathname, O_RDONLY);
int fd = Compat_openat(openatArg, pathname, O_RDONLY);
if (fd < 0)
return NULL;
@ -321,11 +321,11 @@ static inline unsigned long long LinuxProcess_adjustTime(unsigned long long t) {
return t * 100 / jiffy;
}
static bool LinuxProcessList_readStatFile(Process* process, int procFd, char* command, int* commLen) {
static bool LinuxProcessList_readStatFile(Process* process, openat_arg_t procFd, char* command, int* commLen) {
LinuxProcess* lp = (LinuxProcess*) process;
const int commLenIn = *commLen;
*commLen = 0;
int fd = openat(procFd, "stat", O_RDONLY);
int fd = Compat_openat(procFd, "stat", O_RDONLY);
if (fd == -1)
return false;
@ -411,17 +411,21 @@ static bool LinuxProcessList_readStatFile(Process* process, int procFd, char* co
}
static bool LinuxProcessList_statProcessDir(Process* process, int procFd) {
static bool LinuxProcessList_statProcessDir(Process* process, openat_arg_t procFd) {
struct stat sstat;
#ifdef HAVE_OPENAT
int statok = fstat(procFd, &sstat);
#else
int statok = stat(procFd, &sstat);
#endif
if (statok == -1)
return false;
process->st_uid = sstat.st_uid;
return true;
}
static void LinuxProcessList_readIoFile(LinuxProcess* process, int procFd, unsigned long long now) {
int fd = openat(procFd, "io", O_RDONLY);
static void LinuxProcessList_readIoFile(LinuxProcess* process, openat_arg_t procFd, unsigned long long now) {
int fd = Compat_openat(procFd, "io", O_RDONLY);
if (fd == -1) {
process->io_rate_read_bps = NAN;
process->io_rate_write_bps = NAN;
@ -547,7 +551,7 @@ static void LinuxProcessList_calcLibSize_helper(ATTR_UNUSED hkey_t key, void* va
*d += v->size;
}
static uint64_t LinuxProcessList_calcLibSize(int procFd) {
static uint64_t LinuxProcessList_calcLibSize(openat_arg_t procFd) {
FILE* mapsfile = fopenat(procFd, "maps", "r");
if (!mapsfile)
return 0;
@ -625,7 +629,7 @@ static uint64_t LinuxProcessList_calcLibSize(int procFd) {
return total_size / CRT_pageSize;
}
static bool LinuxProcessList_readStatmFile(LinuxProcess* process, int procFd, bool performLookup, unsigned long long now) {
static bool LinuxProcessList_readStatmFile(LinuxProcess* process, openat_arg_t procFd, bool performLookup, unsigned long long now) {
FILE* statmfile = fopenat(procFd, "statm", "r");
if (!statmfile)
return false;
@ -662,7 +666,7 @@ static bool LinuxProcessList_readStatmFile(LinuxProcess* process, int procFd, bo
return r == 7;
}
static bool LinuxProcessList_readSmapsFile(LinuxProcess* process, int procFd, bool haveSmapsRollup) {
static bool LinuxProcessList_readSmapsFile(LinuxProcess* process, openat_arg_t procFd, bool haveSmapsRollup) {
//http://elixir.free-electrons.com/linux/v4.10/source/fs/proc/task_mmu.c#L719
//kernel will return data in chunks of size PAGE_SIZE or less.
FILE* f = fopenat(procFd, haveSmapsRollup ? "smaps_rollup" : "smaps", "r");
@ -700,7 +704,7 @@ static bool LinuxProcessList_readSmapsFile(LinuxProcess* process, int procFd, bo
#ifdef HAVE_OPENVZ
static void LinuxProcessList_readOpenVZData(LinuxProcess* process, int procFd) {
static void LinuxProcessList_readOpenVZData(LinuxProcess* process, openat_arg_t procFd) {
if ( (access(PROCDIR "/vz", R_OK) != 0)) {
free(process->ctid);
process->ctid = NULL;
@ -792,7 +796,7 @@ static void LinuxProcessList_readOpenVZData(LinuxProcess* process, int procFd) {
#endif
static void LinuxProcessList_readCGroupFile(LinuxProcess* process, int procFd) {
static void LinuxProcessList_readCGroupFile(LinuxProcess* process, openat_arg_t procFd) {
FILE* file = fopenat(procFd, "cgroup", "r");
if (!file) {
if (process->cgroup) {
@ -830,7 +834,7 @@ static void LinuxProcessList_readCGroupFile(LinuxProcess* process, int procFd) {
#ifdef HAVE_VSERVER
static void LinuxProcessList_readVServerData(LinuxProcess* process, int procFd) {
static void LinuxProcessList_readVServerData(LinuxProcess* process, openat_arg_t procFd) {
FILE* file = fopenat(procFd, "status", "r");
if (!file)
return;
@ -860,7 +864,7 @@ static void LinuxProcessList_readVServerData(LinuxProcess* process, int procFd)
#endif
static void LinuxProcessList_readOomData(LinuxProcess* process, int procFd) {
static void LinuxProcessList_readOomData(LinuxProcess* process, openat_arg_t procFd) {
FILE* file = fopenat(procFd, "oom_score", "r");
if (!file)
return;
@ -876,7 +880,7 @@ static void LinuxProcessList_readOomData(LinuxProcess* process, int procFd) {
fclose(file);
}
static void LinuxProcessList_readCtxtData(LinuxProcess* process, int procFd) {
static void LinuxProcessList_readCtxtData(LinuxProcess* process, openat_arg_t procFd) {
FILE* file = fopenat(procFd, "status", "r");
if (!file)
return;
@ -903,7 +907,7 @@ static void LinuxProcessList_readCtxtData(LinuxProcess* process, int procFd) {
process->ctxt_total = ctxt;
}
static void LinuxProcessList_readSecattrData(LinuxProcess* process, int procFd) {
static void LinuxProcessList_readSecattrData(LinuxProcess* process, openat_arg_t procFd) {
FILE* file = fopenat(procFd, "attr/current", "r");
if (!file) {
free(process->secattr);
@ -1010,9 +1014,9 @@ static void setCommand(Process* process, const char* command, int len) {
process->commLen = len;
}
static bool LinuxProcessList_readCmdlineFile(Process* process, int procFd) {
static bool LinuxProcessList_readCmdlineFile(Process* process, openat_arg_t procFd) {
LinuxProcess *lp = (LinuxProcess *)process;
int fd = openat(procFd, "cmdline", O_RDONLY);
int fd = Compat_openat(procFd, "cmdline", O_RDONLY);
if (fd == -1)
return false;
@ -1153,7 +1157,7 @@ static bool LinuxProcessList_readCmdlineFile(Process* process, int procFd) {
}
/* /proc/[pid]/comm could change, so should be updated */
if ((fd = openat(procFd, "comm", O_RDONLY)) != -1 &&
if ((fd = Compat_openat(procFd, "comm", O_RDONLY)) != -1 &&
(amtRead = xread(fd, command, sizeof(command) - 1)) > 0) {
command[amtRead - 1] = 0;
lp->mergedCommand.maxLen += amtRead - 1; /* accommodate comm */
@ -1174,7 +1178,14 @@ static bool LinuxProcessList_readCmdlineFile(Process* process, int procFd) {
char filename[MAX_NAME + 1];
/* execve could change /proc/[pid]/exe, so procExe should be updated */
if ((amtRead = readlinkat(procFd, "exe", filename, sizeof(filename) - 1)) > 0) {
#if defined(HAVE_READLINKAT) && defined(HAVE_OPENAT)
amtRead = readlinkat(procFd, "exe", filename, sizeof(filename) - 1);
#else
char path[4096];
xSnprintf(path, sizeof(path), "%s/exe", procFd);
amtRead = readlink(path, filename, sizeof(filename) - 1);
#endif
if (amtRead > 0) {
filename[amtRead] = 0;
lp->mergedCommand.maxLen += amtRead; /* accommodate exe */
if (!lp->procExe || strcmp(filename, lp->procExe)) {
@ -1261,14 +1272,23 @@ static char* LinuxProcessList_updateTtyDevice(TtyDriver* ttyDrivers, unsigned in
return out;
}
static bool LinuxProcessList_recurseProcTree(LinuxProcessList* this, int dirFd, const Process* parent, double period, unsigned long long now) {
static bool LinuxProcessList_recurseProcTree(LinuxProcessList* this, openat_arg_t parentFd, const char* dirname, const Process* parent, double period, unsigned long long now) {
ProcessList* pl = (ProcessList*) this;
const struct dirent* entry;
const Settings* settings = pl->settings;
#ifdef HAVE_OPENAT
int dirFd = openat(parentFd, dirname, O_RDONLY | O_DIRECTORY | O_NOFOLLOW);
if (dirFd < 0)
return false;
DIR* dir = fdopendir(dirFd);
#else
char dirFd[4096];
xSnprintf(dirFd, sizeof(dirFd), "%s/%s", parentFd, dirname);
DIR* dir = opendir(dirFd);
#endif
if (!dir) {
close(dirFd);
Compat_openatArgClose(dirFd);
return false;
}
@ -1277,7 +1297,6 @@ static bool LinuxProcessList_recurseProcTree(LinuxProcessList* this, int dirFd,
bool hideUserlandThreads = settings->hideUserlandThreads;
while ((entry = readdir(dir)) != NULL) {
const char* name = entry->d_name;
int procFd = -1;
// Ignore all non-directories
if (entry->d_type != DT_DIR && entry->d_type != DT_UNKNOWN) {
@ -1310,15 +1329,16 @@ static bool LinuxProcessList_recurseProcTree(LinuxProcessList* this, int dirFd,
proc->tgid = parent ? parent->pid : pid;
procFd = openat(dirFd, name, O_PATH | O_DIRECTORY | O_NOFOLLOW);
#ifdef HAVE_OPENAT
int procFd = openat(dirFd, name, O_PATH | O_DIRECTORY | O_NOFOLLOW);
if (procFd < 0)
goto errorReadingProcess;
#else
char procFd[4096];
xSnprintf(procFd, sizeof(procFd), "%s/%s", dirFd, name);
#endif
int taskDirFd = openat(procFd, "task", O_RDONLY | O_DIRECTORY | O_NOFOLLOW);
if (taskDirFd >= 0) {
/* LinuxProcessList_recurseProcTree() closes taskDirFd */
LinuxProcessList_recurseProcTree(this, taskDirFd, proc, period, now);
}
LinuxProcessList_recurseProcTree(this, procFd, "task", proc, period, now);
/*
* These conditions will not trigger on first occurrence, cause we need to
@ -1331,7 +1351,7 @@ static bool LinuxProcessList_recurseProcTree(LinuxProcessList* this, int dirFd,
proc->show = false;
pl->kernelThreads++;
pl->totalTasks++;
close(procFd);
Compat_openatArgClose(procFd);
continue;
}
if (preExisting && hideUserlandThreads && Process_isUserlandThread(proc)) {
@ -1339,7 +1359,7 @@ static bool LinuxProcessList_recurseProcTree(LinuxProcessList* this, int dirFd,
proc->show = false;
pl->userlandThreads++;
pl->totalTasks++;
close(procFd);
Compat_openatArgClose(procFd);
continue;
}
@ -1473,17 +1493,17 @@ static bool LinuxProcessList_recurseProcTree(LinuxProcessList* this, int dirFd,
if (proc->state == 'R')
pl->runningTasks++;
proc->updated = true;
close(procFd);
Compat_openatArgClose(procFd);
continue;
// Exception handler.
errorReadingProcess:
{
#ifdef HAVE_OPENAT
if (procFd >= 0)
close(procFd);
#endif
if (preExisting) {
ProcessList_remove(pl, proc);
@ -1935,11 +1955,13 @@ void ProcessList_goThroughEntries(ProcessList* super, bool pauseProcessUpdate) {
gettimeofday(&tv, NULL);
unsigned long long now = tv.tv_sec * 1000ULL + tv.tv_usec / 1000ULL;
int procDirfd = open(PROCDIR, O_RDONLY | O_DIRECTORY | O_NOFOLLOW);
if (procDirfd < 0) {
CRT_fatalError("Can not open the root process directory " PROCDIR);
}
/* PROCDIR is an absolute path */
assert(PROCDIR[0] == '/');
#ifdef HAVE_OPENAT
openat_arg_t rootFd = AT_FDCWD;
#else
openat_arg_t rootFd = "";
#endif
/* LinuxProcessList_recurseProcTree() closes procDirfd */
LinuxProcessList_recurseProcTree(this, procDirfd, NULL, period, now);
LinuxProcessList_recurseProcTree(this, rootFd, PROCDIR, NULL, period, now);
}