library: make sure that the proc_t is now fixed length

The former variable length structure created potential
problems for library users like that referenced below.

We will now parallel the same approach newlib uses for
the configure options --enable-oomem & --with-systemd.
Thus, the --enable-oomem and OOMEM_ENABLE #define have
been eliminated and the --with-systemd option (#define
WITH_SYSTEMD) will hereafter impact one function only.

The proc_t struct itself will now *never* be impacted.

Reference(s):
https://gitlab.com/procps-ng/procps/issues/31

Signed-off-by: Jim Warner <james.warner@comcast.net>

diff --git a/configure.ac b/configure.ac
index 80863ecd4d9217cf1d998df7917b2748c735bf54..32d0f728efccf39ecda9f6236c5ac0f9ad7817ab 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -182,14 +182,6 @@ AC_ARG_ENABLE([examples],
 )
 AM_CONDITIONAL(EXAMPLE_FILES, test "x$enable_examples" = xyes)
 
-AC_ARG_ENABLE([oomem],
-  AS_HELP_STRING([--enable-oomem], [add out-of-memory fields to the library and top]),
-  [], [enable_oomem=no]
-)
-if test "x$enable_oomem" = xyes; then
-  AC_DEFINE(OOMEM_ENABLE, 1, [add out-of-memory fields to the library and top])
-fi
-
 AC_ARG_ENABLE([sigwinch],
   AS_HELP_STRING([--enable-sigwinch], [reduce impact of x-windows resize operations on top]),
   [], [enable_sigwinch=no]

diff --git a/proc/readproc.c b/proc/readproc.c
index e06bd0ff8918cc22e3505fc3bd28d6c1c374bb85..f28a062d8669fb8ddb254e91b1712a90bf13668a 100644 (file)
--- a/proc/readproc.c
+++ b/proc/readproc.c
@@ -95,7 +95,6 @@ static inline void free_acquired (proc_t *p, int reuse) {
         if (p->cgroup)   free((void*)*p->cgroup);
         if (p->supgid)   free(p->supgid);
         if (p->supgrp)   free(p->supgrp);
-#ifdef WITH_SYSTEMD
         if (p->sd_mach)  free(p->sd_mach);
         if (p->sd_ouid)  free(p->sd_ouid);
         if (p->sd_seat)  free(p->sd_seat);
@@ -103,7 +102,6 @@ static inline void free_acquired (proc_t *p, int reuse) {
         if (p->sd_slice) free(p->sd_slice);
         if (p->sd_unit)  free(p->sd_unit);
         if (p->sd_uunit) free(p->sd_uunit);
-#endif
 #ifdef QUICK_THREADS
     }
 #endif
@@ -467,7 +465,6 @@ static void supgrps_from_supgids (proc_t *p) {
 }
 
 ///////////////////////////////////////////////////////////////////////
-#ifdef OOMEM_ENABLE
 static void oomscore2proc(const char* S, proc_t *restrict P)
 {
     sscanf(S, "%d", &P->oom_score);
@@ -477,7 +474,6 @@ static void oomadj2proc(const char* S, proc_t *restrict P)
 {
     sscanf(S, "%d", &P->oom_adj);
 }
-#endif
 ///////////////////////////////////////////////////////////////////////
 
 static const char *ns_names[] = {
@@ -520,8 +516,8 @@ static void ns2proc(const char *directory, proc_t *restrict p) {
     }
 }
 
-#ifdef WITH_SYSTEMD
 static void sd2proc(proc_t *restrict p) {
+#ifdef WITH_SYSTEMD
     char buf[64];
     uid_t uid;
 
@@ -534,7 +530,6 @@ static void sd2proc(proc_t *restrict p) {
         snprintf(buf, sizeof(buf), "%d", (int)uid);
         p->sd_ouid = strdup(buf);
     }
-
     if (0 > sd_pid_get_session(p->tid, &p->sd_sess)) {
         p->sd_sess = strdup("-");
         p->sd_seat = strdup("-");
@@ -542,17 +537,22 @@ static void sd2proc(proc_t *restrict p) {
         if (0 > sd_session_get_seat(p->sd_sess, &p->sd_seat))
             p->sd_seat = strdup("-");
     }
-
     if (0 > sd_pid_get_slice(p->tid, &p->sd_slice))
         p->sd_slice = strdup("-");
-
     if (0 > sd_pid_get_unit(p->tid, &p->sd_unit))
         p->sd_unit = strdup("-");
-
     if (0 > sd_pid_get_user_unit(p->tid, &p->sd_uunit))
         p->sd_uunit = strdup("-");
-}
+#else
+    p->sd_mach  = strdup("?");
+    p->sd_ouid  = strdup("?");
+    p->sd_seat  = strdup("?");
+    p->sd_sess  = strdup("?");
+    p->sd_slice = strdup("?");
+    p->sd_unit  = strdup("?");
+    p->sd_uunit = strdup("?");
 #endif
+}
 ///////////////////////////////////////////////////////////////////////
 
 
@@ -992,22 +992,18 @@ static proc_t* simple_readproc(PROCTAB *restrict const PT, proc_t *restrict cons
     } 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);
 
-#ifdef WITH_SYSTEMD
     if (unlikely(flags & PROC_FILLSYSTEMD))     // get sd-login.h stuff
         sd2proc(p);
-#endif
 
     if (unlikely(flags & PROC_FILL_LXC))        // value the lxc name
         p->lxcname = lxc_containers(path);
@@ -1115,10 +1111,8 @@ static proc_t* simple_readtask(PROCTAB *restrict const PT, const proc_t *restric
         } else
             t->cgroup = NULL;
 
-#ifdef WITH_SYSTEMD
         if (unlikely(flags & PROC_FILLSYSTEMD))         // get sd-login.h stuff
             sd2proc(t);
-#endif
 
         if (unlikely(flags & PROC_FILL_LXC))            // value the lxc name
             t->lxcname = lxc_containers(path);
@@ -1138,7 +1132,6 @@ static proc_t* simple_readtask(PROCTAB *restrict const PT, const proc_t *restric
         if (t->supgid) free(t->supgid);
         t->supgid   = p->supgid;
         t->supgrp   = p->supgrp;
-#ifdef WITH_SYSTEMD
         t->sd_mach  = p->sd_mach;
         t->sd_ouid  = p->sd_ouid;
         t->sd_seat  = p->sd_seat;
@@ -1146,20 +1139,17 @@ static proc_t* simple_readtask(PROCTAB *restrict const PT, const proc_t *restric
         t->sd_slice = p->sd_slice;
         t->sd_unit  = p->sd_unit;
         t->sd_uunit = p->sd_uunit;
-#endif
         t->lxcname = p->lxcname;
         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);

diff --git a/proc/readproc.h b/proc/readproc.h
index f87b0e9f841d0a61165216ae4b05819779a80605..ee7f5ca55f64a04b882d4e78d4c5c3e04fa7f891 100644 (file)
--- a/proc/readproc.h
+++ b/proc/readproc.h
@@ -167,14 +167,11 @@ typedef struct proc_t {
        tpgid,          // stat            terminal process group id
        exit_signal,    // stat            might not be SIGCHLD
        processor;      // stat            current (or most recent?) CPU
-#ifdef OOMEM_ENABLE
     int
         oom_score,      // oom_score       (badness for OOM killer)
         oom_adj;        // oom_adj         (adjustment to OOM score)
-#endif
     long
         ns[NUM_NS];     // (ns subdir)     inode number of namespaces
-#ifdef WITH_SYSTEMD
     char
         *sd_mach,       // n/a             systemd vm/container name
         *sd_ouid,       // n/a             systemd session owner uid
@@ -183,7 +180,6 @@ typedef struct proc_t {
         *sd_slice,      // n/a             systemd slice unit
         *sd_unit,       // n/a             systemd system unit id
         *sd_uunit;      // n/a             systemd user unit id
-#endif
     const char
         *lxcname;       // n/a             lxc container name
 } proc_t;