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library: correct a flawed approach for PROCPS_FILL_UID

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Gosh, just because nobody uses some newlib provision I
guess, since it is being offered, it ought to actually
be tested at some point. Well, that point just arrived
and guess what? A surprise: some bugs were discovered.

The procps_pids_select function established a for loop
wherein readproc is called until the passed 'maxthese'
limit. Unfortunately this was incorrect for 2 reasons:

1. For PROCPS_FILL_PID results are limited by what the
oldlib finds, having established the pid list at open.
Total found already cannot exceed a passed 'maxthese';

2. With PROCPS_FILL_UID, returned results could exceed
a 'maxthese' thus making the for loop incorrect again.

[ plus yours truly neglected to forward the required ]
[ UIDs total to our old library, another oops biggie ]

In summary: the loop should have been forever, exiting
only when all those identified procs had been located.

So, while addressing those bugs, I've consolidated all
the retrieval code (initialize, iterate, summarize) in
a single helper function which will now serve both the
procps_pids_reap and select functions. And as a result
those guys were reduced to quite trivial housekeeping.

This patch, hopefully, completes the normalization for
reap/select (fill), which began with references shown.

Reference(s):
commit 0c953eccc5
commit 747dfc5987

Signed-off-by: Jim Warner <james.warner@comcast.net>
This commit is contained in:
Jim Warner 2015-10-08 00:00:00 -05:00 committed by Craig Small
parent 99a657b365
commit bc616b3615
1 changed files with 99 additions and 92 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

191
proc/pids.c
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@ -63,16 +63,23 @@ struct stacks_extent {
struct stacks_extent *next;
};
struct fetch_support {
struct pids_stack **anchor; // reapable/fillable (consolidated extents)
int n_alloc; // number of above pointers allocated
int n_inuse; // number of above pointers occupied
int n_alloc_save; // last known summary.stacks allocation
struct pids_reap summary; // counts + stacks for return to caller
};
struct procps_pidsinfo {
int refcount;
int maxitems; // includes 'physical_end' delimiter
int curitems; // includes 'logical_end' delimiter
enum pids_item *items; // includes 'phy/log_end' delimiters
struct pids_stack **anchor; // reapable stacks (consolidated extents)
int alloc_total; // number of above pointers allocated
int inuse_total; // number of above pointers occupied
struct stacks_extent *extents; // anchor for all resettable extents
struct stacks_extent *otherexts; // anchor for single stack invariant extents
struct fetch_support reap; // support for procps_pids_reap
struct fetch_support select; // support for procps_pids_select
int history_yes; // need historical data
struct history_info *hist; // pointer to historical support data
int dirty_stacks; // extents need dynamic storage clean
@ -81,10 +88,6 @@ struct procps_pidsinfo {
unsigned pgs2k_shift; // to convert some proc vaules
unsigned flags; // the old library PROC_FILL flagss
PROCTAB *PT; // the old library essential interface
int select_maxthese; // largest last known user maxthese
struct stacks_extent *select; // select anchor, subset of 'extents' above
struct pids_reap filled; // counts + stacks for 'procps_pids_select'
struct pids_reap reaped; // counts + stacks for 'procps_pids_reap'
unsigned long hertz; // for TIME_ALL & TIME_ELAPSED calculations
unsigned long long boot_seconds; // for TIME_ELAPSED calculation
};
@ -884,16 +887,20 @@ static inline int oldproc_open (
unsigned supp_flgs,
...)
{
va_list vl;
int *ids;
int num = 0;
if (info->PT == NULL) {
va_start(vl, supp_flgs);
ids = va_arg(vl, int*);
if (info->flags | PROC_UID) num = va_arg(vl, int);
va_end(vl);
if (NULL == (info->PT = openproc(info->flags | supp_flgs, ids)))
if (NULL == (info->PT = openproc(info->flags | supp_flgs, ids, num)))
return 0;
}
return 1;
} // end: oldproc_open
@ -981,7 +988,9 @@ static void validate_stacks (
#endif
// ___ Former Public Functions ||||||||||||||||||||||||||||||||||||||||||||||||
// ___ Special Temporary Section |||||||||||||||||||||||||||||||||||||||||||||
// [ contains former public functions and other dependent routine(s) while we ]
// [ resist using forward declarations yet still maintain an alphabetic order ]
/*
* alloc_stacks():
@ -1048,6 +1057,7 @@ static struct stacks_extent *alloc_stacks (
} // end: alloc_stacks
#if 0 // --------------------------- not (currently) needed
static int dealloc_stacks (
struct procps_pidsinfo *info,
struct stacks_extent **these)
@ -1065,6 +1075,60 @@ static int dealloc_stacks (
*these = NULL;
return rc;
} // end: dealloc_stacks
#endif // -------------------------- not (currently) needed
static int fetch_helper (
struct procps_pidsinfo *info,
struct fetch_support *this)
{
#define n_alloc this->n_alloc
#define n_inuse this->n_inuse
static proc_t task; // static for initial zeroes + later dynamic free(s)
struct stacks_extent *ext;
if (info == NULL || this == NULL)
return -1;
// initialize stuff -----------------------------------
if (!this->anchor) {
if ((!(this->anchor = calloc(sizeof(void *), MEMORY_INCR)))
|| (!(this->summary.stacks = calloc(sizeof(void *), MEMORY_INCR)))
|| (!(ext = alloc_stacks(info, MEMORY_INCR))))
return -1;
memcpy(this->anchor, ext->stacks, sizeof(void *) * MEMORY_INCR);
n_alloc = MEMORY_INCR;
}
if (info->dirty_stacks)
cleanup_stacks_all(info);
toggle_history(info);
memset(&this->summary.counts, 0, sizeof(struct pids_counts));
// iterate stuff --------------------------------------
n_inuse = 0;
while (info->read_something(info->PT, &task)) {
if (!(n_inuse < n_alloc)) {
n_alloc += MEMORY_INCR;
if ((!(this->anchor = realloc(this->anchor, sizeof(void *) * n_alloc)))
|| (!(ext = alloc_stacks(info, MEMORY_INCR))))
return -1;
memcpy(this->anchor + n_inuse, ext->stacks, sizeof(void *) * MEMORY_INCR);
}
if (!tally_proc(info, &this->summary.counts, &task))
return -1;
assign_results(info, this->anchor[n_inuse++], &task);
}
// finalize stuff -------------------------------------
if (this->n_alloc_save != n_alloc
&& !(this->summary.stacks = realloc(this->summary.stacks, sizeof(void *) * n_alloc)))
return -1;
memcpy(this->summary.stacks, this->anchor, sizeof(void *) * n_alloc);
this->n_alloc_save = n_alloc;
return n_inuse; // callers beware, this might be zero !
#undef n_alloc
#undef n_inuse
} // end: fetch_helper
// ___ Public Functions |||||||||||||||||||||||||||||||||||||||||||||||||||||||
@ -1212,12 +1276,7 @@ PROCPS_EXPORT struct pids_reap *procps_pids_reap (
struct procps_pidsinfo *info,
enum pids_reap_type which)
{
#define n_alloc info->alloc_total
#define n_inuse info->inuse_total
static proc_t task; // static for initial zeroes + later dynamic free(s)
proc_t*(*reap_something)(PROCTAB*, proc_t*);
struct stacks_extent *ext;
int n_save;
int rc;
if (info == NULL || READS_BEGUN)
return NULL;
@ -1225,50 +1284,16 @@ PROCPS_EXPORT struct pids_reap *procps_pids_reap (
return NULL;
if (which != PROCPS_REAP_TASKS_ONLY && which != PROCPS_REAP_THREADS_TOO)
return NULL;
n_save = n_alloc;
if (!info->anchor) {
if ((!(info->anchor = calloc(sizeof(void *), MEMORY_INCR)))
|| (!(info->reaped.stacks = calloc(sizeof(void *), MEMORY_INCR)))
|| (!(ext = alloc_stacks(info, MEMORY_INCR))))
return NULL;
memcpy(info->anchor, ext->stacks, sizeof(void *) * MEMORY_INCR);
n_save = info->alloc_total = MEMORY_INCR;
}
if (info->dirty_stacks)
cleanup_stacks_all(info);
memset(&info->reaped.counts, 0, sizeof(struct pids_counts));
if (!oldproc_open(info, 0))
return NULL;
toggle_history(info);
reap_something = which ? readeither : readproc;
info->read_something = which ? readeither : readproc;
for (n_inuse = 0; ; n_inuse++) {
if (n_inuse == n_alloc) {
n_alloc += MEMORY_INCR;
if ((!(info->anchor = realloc(info->anchor, sizeof(void *) * n_alloc)))
|| (!(ext = alloc_stacks(info, MEMORY_INCR))))
return NULL;
memcpy(info->anchor + n_inuse, ext->stacks, sizeof(void *) * MEMORY_INCR);
}
if (NULL == reap_something(info->PT, &task))
break;
if (!tally_proc(info, &info->reaped.counts, &task)) {
oldproc_close(info);
return NULL;
}
assign_results(info, info->anchor[n_inuse], &task);
}
rc = fetch_helper(info, &info->reap);
oldproc_close(info);
if (n_save != n_alloc
&& !(info->reaped.stacks = realloc(info->reaped.stacks, sizeof(void *) * n_alloc)))
return NULL;
memcpy(info->reaped.stacks, info->anchor, sizeof(void *) * n_alloc);
return &info->reaped;
#undef n_alloc
#undef n_inuse
// we better have found at least 1 pid
return (rc > 0) ? &info->reap.summary : NULL;
} // end: procps_pids_reap
@ -1329,15 +1354,21 @@ PROCPS_EXPORT int procps_pids_reset (
} // end: procps_pids_reset
/* procps_pids_select():
*
* Harvest any processes matching the specified PID or UID and provide the
* result stacks along with a summary of the information gathered.
*
* Returns: pointer to a pids_reap struct on success, NULL on error.
*/
PROCPS_EXPORT struct pids_reap *procps_pids_select (
struct procps_pidsinfo *info,
unsigned *these,
int maxthese,
enum pids_fill_type which)
{
static proc_t task; // static for initial zeroes + later dynamic free(s)
unsigned ids[FILL_ID_MAX + 1];
int i;
int rc;
if (info == NULL || these == NULL || READS_BEGUN)
return NULL;
@ -1346,47 +1377,19 @@ PROCPS_EXPORT struct pids_reap *procps_pids_select (
if (which != PROCPS_FILL_PID && which != PROCPS_FILL_UID)
return NULL;
if (info->dirty_stacks)
cleanup_stacks_all(info);
if (maxthese > info->select_maxthese && info->select)
dealloc_stacks(info, &info->select);
if(!info->select) {
if (!(info->select = alloc_stacks(info, maxthese)))
return NULL;
info->select_maxthese = maxthese;
}
memset(&info->filled, 0, sizeof(struct pids_reap));
// this zero delimiter is really only needed with PROCPS_FILL_PID
memcpy(ids, these, sizeof(unsigned) * maxthese);
ids[maxthese] = 0;
if (!oldproc_open(info, which, ids, maxthese)) {
dealloc_stacks(info, &info->select);
if (!oldproc_open(info, which, ids, maxthese))
return NULL;
}
toggle_history(info);
info->read_something = readproc;
for (i = 0; i < maxthese; i++) {
if (info->select->stacks[i] == NULL)
break;
if (!readproc(info->PT, &task))
break;
if (!tally_proc(info, &info->filled.counts, &task)) {
oldproc_close(info);
dealloc_stacks(info, &info->select);
return NULL;
}
assign_results(info, info->select->stacks[i], &task);
}
rc = fetch_helper(info, &info->select);
oldproc_close(info);
#ifdef FPRINT_STACKS
validate_stacks(info->select, __func__);
#endif
info->filled.stacks = info->select->stacks;
return &info->filled;
// no guarantee any pids/uids were found
return (rc > -1) ? &info->select.summary : NULL;
} // end: procps_pids_select
@ -1469,10 +1472,14 @@ PROCPS_EXPORT int procps_pids_unref (
ext = nextext;
};
}
if ((*info)->reaped.stacks)
free((*info)->reaped.stacks);
if ((*info)->anchor)
free((*info)->anchor);
if ((*info)->reap.anchor)
free((*info)->reap.anchor);
if ((*info)->reap.summary.stacks)
free((*info)->reap.summary.stacks);
if ((*info)->select.anchor)
free((*info)->select.anchor);
if ((*info)->select.summary.stacks)
free((*info)->select.summary.stacks);
if ((*info)->items)
free((*info)->items);
if ((*info)->hist) {