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| | /*
* Copyright (C) mwrap hackers <mwrap-perl@80x24.org>
* License: GPL-3.0+ <https://www.gnu.org/licenses/gpl-3.0.txt>
* Disclaimer: I don't really know my way around XS or Perl internals well
*/
#define _LGPL_SOURCE /* allows URCU to inline some stuff */
#ifndef _GNU_SOURCE
# define _GNU_SOURCE
#endif
#include "mymalloc.h" /* includes dlmalloc_c.h */
#ifndef MWRAP_PERL
# define MWRAP_PERL 0
#endif
#ifndef MWRAP_RUBY
# define MWRAP_RUBY 0
#endif
/* set a sensible max to avoid stack overflows */
#ifndef MWRAP_BT_MAX
# define MWRAP_BT_MAX 32
#endif
#include <execinfo.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <pthread.h>
#include <signal.h>
#include <urcu-bp.h>
#include <urcu/rculfhash.h>
#include <urcu/rculist.h>
#include <limits.h>
#if MWRAP_PERL
# include "EXTERN.h"
# include "perl.h"
# include "XSUB.h"
# include "embed.h"
# include "ppport.h"
#endif
/*
* XXH3 (truncated to 32-bits) seems to provide a ~2% speedup.
* XXH32 doesn't show improvements over jhash despite rculfhash
* only supporting 32-bit hash values.
*/
#if defined(HAVE_XXHASH)
# define XXH_INLINE_ALL
# include <xxhash.h>
# if !defined(XXH3_64bits)
# warning XXH3_64bits not defined
# endif
#endif
#if !defined(XXH3_64bits)
# include "jhash.h"
#endif
#define U24_MAX (1U << 24)
/*
* Perl doesn't have a GC the same way (C) Ruby does, so no GC count.
* Instead, the relative age of an object is the number of total bytes
* allocated (and we don't care about overflow on 32-bit since
* hardly anybody still uses it).
*/
static size_t total_bytes_inc, total_bytes_dec, nr_file, nr_src_loc;
static uint32_t bt_req_depth;
#if MWRAP_PERL
extern pthread_key_t __attribute__((weak)) PL_thr_key;
extern const char __attribute__((weak)) PL_memory_wrap[]; /* needed for -O0 */
# if !defined(PERL_IMPLICIT_CONTEXT)
static size_t *root_locating; /* determines if PL_curcop is our thread */
# endif
#endif /* MWRAP_PERL */
#if MWRAP_RUBY
static void mw_ruby_set_generation(size_t *, size_t);
# define SET_GENERATION(gen, size) mw_ruby_set_generation(gen, size)
static size_t last_gc_count; /* for httpd which runs in a non-GVL thread */
#endif /* MWRAP_RUBY */
#ifndef SET_GENERATION /* C-only builds w/o Perl|Ruby */
# define SET_GENERATION(gen, size) \
*gen = uatomic_add_return(&total_bytes_inc, size)
#endif /* !SET_GENERATION */
/* generic stuff: */
static MWRAP_TSD size_t locating;
static struct cds_lfht *files, *totals;
union padded_mutex {
pthread_mutex_t mtx;
char pad[64]; /* cache alignment for common CPUs */
};
/* a pool of mutexes for all "struct src_loc" */
#define MUTEX_NR (1 << 6)
#define MUTEX_MASK (MUTEX_NR - 1)
static union padded_mutex mutexes[MUTEX_NR] = {
[0 ... (MUTEX_NR-1)].mtx = PTHREAD_MUTEX_INITIALIZER
};
#ifdef static_assert
/* we only use uint32_t for pathname storage for struct alignment */
static_assert(UINT32_MAX > PATH_MAX, "UINT32_MAX > PATH_MAX");
#endif
static struct cds_lfht *lfht_new(size_t size)
{
return cds_lfht_new(size, 1, 0, CDS_LFHT_AUTO_RESIZE, 0);
}
static void reset_mutexes(void)
{
size_t i;
for (i = 0; i < MUTEX_NR; i++)
CHECK(int, 0, pthread_mutex_init(&mutexes[i].mtx, 0));
}
#ifndef HAVE_MEMPCPY
static void *my_mempcpy(void *dest, const void *src, size_t n)
{
return (char *)memcpy(dest, src, n) + n;
}
#define mempcpy(dst,src,n) my_mempcpy(dst,src,n)
#endif
/* stolen from glibc: */
#define RETURN_ADDRESS(nr) \
__builtin_extract_return_addr(__builtin_return_address(nr))
#define SRC_LOC_BT(bt) union stk_bt bt; do { \
uint32_t depth = locating ? 1 : CMM_LOAD_SHARED(bt_req_depth); \
switch (depth) { \
case 0: \
case 1: bt.sl.bt_len = 1; bt.sl.bt[0] = RETURN_ADDRESS(0); break; \
default: /* skip 1st level of BT since thats our function */ \
mwrap_assert(depth <= MWRAP_BT_MAX); \
++locating; \
long n = (long)backtrace(bt_dst(&bt), depth); \
--locating; \
bt.sl.bt_len = n <= 1 ? 0 : (uint32_t)n - 1; \
if (n > 1) mwrap_assert(bt.sl.bt[0] == RETURN_ADDRESS(0)); \
} \
} while (0)
/*
* only for interpreted sources (Perl/Ruby/etc), not backtrace_symbols* files
* Allocated via real_malloc / real_free
*/
struct src_file {
struct cds_lfht_node nd; /* <=> files table */
uint32_t fn_hash;
uint32_t fn_len; /* < PATH_MAX */
char fn[]; /* NUL-terminated */
};
/* allocated via real_malloc, immortal for safety reasons */
struct src_loc {
size_t total;
size_t freed_bytes;
size_t allocations;
size_t frees;
size_t age_total; /* (age_total / frees) => mean age at free */
size_t max_lifespan;
struct cds_lfht_node hnode; /* <=> totals table */
struct cds_list_head allocs; /* <=> alloc_hdr.node */
uint32_t loc_hash;
uint8_t bt_len;
/* next 3 fields contiguous for hash_src_loc(): */
unsigned lineno:24; /* nobody should have >=16.7 LoC in one file */
struct src_file *f;
void *bt[];
} __attribute__((packed,aligned(8)));
/* sizeof() doesn't work on bitfields */
#define SIZEOF_LINENO (size_t)(24 / 8)
/*
* Every allocation has this in the header, maintain alignment with malloc
* Do not expose this to Perl code because of use-after-free concerns.
*/
struct alloc_hdr {
struct cds_list_head anode; /* <=> src_loc.allocs */
union {
struct {
size_t gen; /* global age || rb_gc_count() */
struct src_loc *loc;
} live;
struct rcu_head dead;
} as;
void *real; /* what to call real_free on (exists for *memalign) */
size_t size;
};
/* on-stack structures */
union stk_sf {
struct src_file sf;
char buf_[sizeof(struct src_file) + PATH_MAX];
};
union stk_bt {
struct src_loc sl;
/* we subtract one level from MWRAP_BT_MAX since we discard one
* level of backtrace(3) (see below for why) */
char buf_[sizeof(struct src_loc) + sizeof(void *) * (MWRAP_BT_MAX-1)];
};
/*
* we discard the 1st-level of the backtrace(3) since it's our *alloc
* function (and therefore uninteresting), so we want backtrace(3) to
* write to bt->sl.bt[-1] so that bt->sl.bt[0] is the first interesting
* thing.
*/
#ifdef static_assert
static_assert(offsetof(struct src_loc, f) + sizeof(void *) ==
offsetof(struct src_loc, bt),
"bt lineno is is bt[-1]");
#endif
static void **bt_dst(union stk_bt *bt)
{
return (void **)&bt->sl.f;
}
static struct alloc_hdr *ptr2hdr(void *p)
{
return (struct alloc_hdr *)((uintptr_t)p - sizeof(struct alloc_hdr));
}
static void *hdr2ptr(struct alloc_hdr *h)
{
return (void *)((uintptr_t)h + sizeof(struct alloc_hdr));
}
static int loc_is_addr(const struct src_loc *l)
{
return l->f == NULL;
}
static size_t bt_bytelen(const struct src_loc *l)
{
return sizeof(l->bt[0]) * l->bt_len;
}
static size_t src_loc_hash_len(const struct src_loc *l)
{
return sizeof(l->f) + SIZEOF_LINENO + bt_bytelen(l);
}
static void *src_loc_hash_tip(const struct src_loc *l)
{
return (void *)((uintptr_t)&l->bt_len + sizeof(l->bt_len));
}
static int loc_eq(struct cds_lfht_node *node, const void *key)
{
const struct src_loc *existing;
const struct src_loc *k = key;
existing = caa_container_of(node, struct src_loc, hnode);
return (k->bt_len == existing->bt_len &&
!memcmp(src_loc_hash_tip(k), src_loc_hash_tip(existing),
src_loc_hash_len(k)));
}
static int fn_eq(struct cds_lfht_node *node, const void *key)
{
const struct src_file *existing;
const struct src_file *k = key;
existing = caa_container_of(node, struct src_file, nd);
return (k->fn_len == existing->fn_len &&
!memcmp(k->fn, existing->fn, k->fn_len));
}
static struct src_loc *src_loc_get(struct cds_lfht *t, const struct src_loc *k)
{
struct cds_lfht_iter iter;
struct cds_lfht_node *cur;
mwrap_assert(rcu_read_ongoing());
cds_lfht_lookup(t, k->loc_hash, loc_eq, k, &iter);
cur = cds_lfht_iter_get_node(&iter);
return cur ? caa_container_of(cur, struct src_loc, hnode) : NULL;
}
static struct src_loc *totals_add_rcu(const struct src_loc *k)
{
struct src_loc *l;
struct cds_lfht *t = CMM_LOAD_SHARED(totals);
if (!t) return NULL;
again:
l = src_loc_get(t, k);
if (l) {
uatomic_add(&l->total, k->total);
uatomic_inc(&l->allocations);
} else {
size_t n = bt_bytelen(k) + sizeof(*k);
struct cds_lfht_node *cur;
l = real_malloc(n);
if (!l) return l;
memcpy(l, k, n);
l->freed_bytes = 0;
l->age_total = 0;
l->max_lifespan = 0;
l->freed_bytes = 0;
l->frees = 0;
l->allocations = 1;
CDS_INIT_LIST_HEAD(&l->allocs);
cur = cds_lfht_add_unique(t, l->loc_hash, loc_eq, l, &l->hnode);
if (cur == &l->hnode) {
uatomic_inc(&nr_src_loc);
} else { /* lost race */
rcu_read_unlock();
real_free(l);
rcu_read_lock();
goto again;
}
}
return l;
}
static uint32_t do_hash(const void *p, size_t len)
{
#if defined(XXH3_64bits)
union {
XXH64_hash_t u64;
uint32_t u32[2];
} u;
u.u64 = XXH3_64bits(p, len);
return u.u32[1];
#else
return jhash(p, len, 0xdeadbeef);
#endif
}
static void hash_src_loc(struct src_loc *l)
{
l->loc_hash = do_hash(src_loc_hash_tip(l), src_loc_hash_len(l));
}
static struct src_file *src_file_get(struct cds_lfht *t, struct src_file *k,
const char *fn, size_t fn_len)
{
struct cds_lfht_iter iter;
struct cds_lfht_node *cur;
mwrap_assert(t); /* caller should've bailed if missing */
if (fn_len >= PATH_MAX)
return NULL;
k->fn_len = (uint32_t)fn_len;
memcpy(k->fn, fn, fn_len);
k->fn[fn_len] = 0;
k->fn_hash = do_hash(k->fn, fn_len);
mwrap_assert(rcu_read_ongoing());
cds_lfht_lookup(t, k->fn_hash, fn_eq, k, &iter);
cur = cds_lfht_iter_get_node(&iter);
return cur ? caa_container_of(cur, struct src_file, nd) : NULL;
}
#if MWRAP_PERL
static const COP *mwp_curcop(void)
{
if (&PL_thr_key) { /* are we even in a Perl process? */
# ifdef PERL_IMPLICIT_CONTEXT
if (aTHX) return PL_curcop;
# else /* !PERL_IMPLICIT_CONTEXT */
if (&locating == root_locating) return PL_curcop;
# endif /* PERL_IMPLICIT_CONTEXT */
}
return NULL;
}
static const char *mw_perl_src_file_cstr(unsigned *lineno)
{
const COP *cop = mwp_curcop();
*lineno = cop ? CopLINE(cop) : 0;
return cop ? CopFILE(cop) : NULL;
}
# define SRC_FILE_CSTR(lineno) mw_perl_src_file_cstr(lineno)
#endif /* MWRAP_PERL */
#if MWRAP_RUBY
static const char *mw_ruby_src_file_cstr(unsigned *lineno);
# define SRC_FILE_CSTR(lineno) mw_ruby_src_file_cstr(lineno)
#endif /* MWRAP_RUBY */
#ifndef SRC_FILE_CSTR /* for C-only compilation */
# define SRC_FILE_CSTR(lineno) (NULL)
#endif /* !SRC_FILE_CSTR */
static struct src_loc *assign_line(size_t size, struct src_loc *sl,
const char *fn, unsigned lineno)
{
struct src_file *f;
union stk_sf sf;
struct cds_lfht_node *cur;
struct cds_lfht *t = CMM_LOAD_SHARED(files);
mwrap_assert(t);
size_t len = strlen(fn);
if (len >= PATH_MAX)
len = PATH_MAX - 1;
if (lineno == UINT_MAX) { /* NOLINE in Perl is UINT_MAX */
lineno = U24_MAX;
} else if (lineno > U24_MAX) {
fprintf(stderr,
"%s:%u line number exceeds limit (%u), capped\n",
fn, lineno, U24_MAX);
lineno = U24_MAX;
}
again:
f = src_file_get(t, &sf.sf, fn, len);
if (!f) { /* doesn't exist, add a new one */
f = real_malloc(sizeof(*f) + len + 1);
if (!f) return NULL;
memcpy(f, &sf.sf, sizeof(*f) + len + 1);
cur = cds_lfht_add_unique(t, f->fn_hash, fn_eq, f, &f->nd);
if (cur == &f->nd) {
uatomic_inc(&nr_file);
} else { /* lost race */
rcu_read_unlock();
real_free(f);
rcu_read_lock();
goto again;
}
}
sl->total = size;
sl->f = f;
sl->lineno = lineno;
if (f && !bt_req_depth)
sl->bt_len = 0;
hash_src_loc(sl);
return totals_add_rcu(sl);
}
static struct src_loc *
update_stats_rcu_lock(size_t *gen, size_t size, struct src_loc *sl)
{
struct cds_lfht *t = CMM_LOAD_SHARED(totals);
struct src_loc *ret = NULL;
if (caa_unlikely(!t)) return 0; /* not initialized */
if (locating++) goto out; /* do not recurse into another *alloc */
SET_GENERATION(gen, size);
unsigned lineno;
const char *fn = SRC_FILE_CSTR(&lineno);
rcu_read_lock();
if (fn)
ret = assign_line(size, sl, fn, lineno);
if (!ret) { /* no associated Perl|Ruby code, just C/C++ */
sl->total = size;
sl->f = NULL;
sl->lineno = 0;
hash_src_loc(sl);
ret = totals_add_rcu(sl);
}
out:
--locating;
return ret;
}
size_t malloc_usable_size(void *p)
{
return ptr2hdr(p)->size;
}
static void free_hdr_rcu(struct rcu_head *dead)
{
struct alloc_hdr *h = caa_container_of(dead, struct alloc_hdr, as.dead);
real_free(h->real);
}
static pthread_mutex_t *src_loc_mutex_lock(const struct src_loc *l)
{
pthread_mutex_t *mtx = &mutexes[l->loc_hash & MUTEX_MASK].mtx;
CHECK(int, 0, pthread_mutex_lock(mtx));
return mtx;
}
void free(void *p)
{
if (p) {
struct alloc_hdr *h = ptr2hdr(p);
struct src_loc *l = h->as.live.loc;
if (l) {
size_t current_bytes = uatomic_read(&total_bytes_inc);
size_t age = current_bytes - h->as.live.gen;
uatomic_add(&total_bytes_dec, h->size);
uatomic_add(&l->freed_bytes, h->size);
uatomic_set(&h->size, 0);
uatomic_inc(&l->frees);
uatomic_add(&l->age_total, age);
pthread_mutex_t *mtx = src_loc_mutex_lock(l);
cds_list_del_rcu(&h->anode);
if (age > l->max_lifespan)
l->max_lifespan = age;
CHECK(int, 0, pthread_mutex_unlock(mtx));
call_rcu(&h->as.dead, free_hdr_rcu);
} else {
real_free(h->real);
}
}
}
static void
alloc_insert_rcu(struct src_loc *sl, struct alloc_hdr *h, size_t size,
void *real)
{
h->size = size;
h->real = real;
size_t gen = 0;
struct src_loc *l = update_stats_rcu_lock(&gen, size, sl);
h->as.live.loc = l;
h->as.live.gen = gen;
if (l) {
pthread_mutex_t *mtx = src_loc_mutex_lock(l);
cds_list_add_rcu(&h->anode, &l->allocs);
CHECK(int, 0, pthread_mutex_unlock(mtx));
rcu_read_unlock();
}
}
static bool ptr_is_aligned(void *ptr, size_t alignment)
{
return ((uintptr_t) ptr & (alignment - 1)) == 0;
}
static void *ptr_align(void *ptr, size_t alignment)
{
return (void *)(((uintptr_t) ptr + (alignment - 1)) & ~(alignment - 1));
}
static bool is_power_of_two(size_t n)
{
return (n & (n - 1)) == 0;
}
static int
mwrap_memalign(void **pp, size_t alignment, size_t size, struct src_loc *sl)
{
void *real;
size_t asize;
size_t d = alignment / sizeof(void*);
size_t r = alignment % sizeof(void*);
if (r != 0 || d == 0 || !is_power_of_two(d))
return EINVAL;
if (alignment <= MALLOC_ALIGNMENT) {
void *p = malloc(size);
if (!p) return ENOMEM;
*pp = p;
return 0;
}
for (; alignment < sizeof(struct alloc_hdr); alignment *= 2)
; /* double alignment until >= sizeof(struct alloc_hdr) */
if (__builtin_add_overflow(size, alignment, &asize) ||
__builtin_add_overflow(asize, sizeof(struct alloc_hdr), &asize))
return ENOMEM;
real = real_malloc(asize);
if (real) {
void *p = hdr2ptr(real);
if (!ptr_is_aligned(p, alignment))
p = ptr_align(p, alignment);
struct alloc_hdr *h = ptr2hdr(p);
alloc_insert_rcu(sl, h, size, real);
*pp = p;
}
return real ? 0 : ENOMEM;
}
static void *memalign_result(int err, void *p)
{
if (caa_unlikely(err))
errno = err;
return p;
}
void *memalign(size_t alignment, size_t size)
{
void *p = NULL;
SRC_LOC_BT(bt);
int err = mwrap_memalign(&p, alignment, size, &bt.sl);
return memalign_result(err, p);
}
int posix_memalign(void **p, size_t alignment, size_t size)
{
SRC_LOC_BT(bt);
return mwrap_memalign(p, alignment, size, &bt.sl);
}
/* these aliases aren't needed for glibc, not sure about other libcs... */
void *aligned_alloc(size_t, size_t) __attribute__((alias("memalign")));
void cfree(void *) __attribute__((__nothrow__))
__attribute__((__leaf__)) __attribute__((alias("free")));
void *valloc(size_t size)
{
ensure_initialization();
SRC_LOC_BT(bt);
void *p = NULL;
int err = mwrap_memalign(&p, mparams.page_size, size, &bt.sl);
return memalign_result(err, p);
}
#if __GNUC__ < 7
# define add_overflow_p(a,b) __extension__({ \
__typeof__(a) _c; \
__builtin_add_overflow(a,b,&_c); \
})
#else
# define add_overflow_p(a,b) \
__builtin_add_overflow_p((a),(b),(__typeof__(a+b))0)
#endif
static size_t size_align(size_t size, size_t alignment)
{
return ((size + (alignment - 1)) & ~(alignment - 1));
}
void *pvalloc(size_t size)
{
void *p = NULL;
ensure_initialization();
if (add_overflow_p(size, mparams.page_size)) {
errno = ENOMEM;
return 0;
}
size = size_align(size, mparams.page_size);
SRC_LOC_BT(bt);
int err = mwrap_memalign(&p, mparams.page_size, size, &bt.sl);
return memalign_result(err, p);
}
void *malloc(size_t size)
{
size_t asize;
if (__builtin_add_overflow(size, sizeof(struct alloc_hdr), &asize))
goto enomem;
void *p = real_malloc(asize);
if (p) {
SRC_LOC_BT(bt);
struct alloc_hdr *h = p;
alloc_insert_rcu(&bt.sl, h, size, h);
return hdr2ptr(h);
}
enomem:
errno = ENOMEM;
return 0;
}
void *calloc(size_t nmemb, size_t size)
{
size_t asize;
if (__builtin_mul_overflow(size, nmemb, &size))
goto enomem;
if (__builtin_add_overflow(size, sizeof(struct alloc_hdr), &asize))
goto enomem;
void *p = real_malloc(asize);
if (p) {
struct alloc_hdr *h = p;
SRC_LOC_BT(bt);
alloc_insert_rcu(&bt.sl, h, size, h);
return memset(hdr2ptr(h), 0, size);
}
enomem:
errno = ENOMEM;
return 0;
}
void *realloc(void *ptr, size_t size)
{
size_t asize;
if (!size) {
free(ptr);
return 0;
}
if (__builtin_add_overflow(size, sizeof(struct alloc_hdr), &asize))
goto enomem;
void *p = real_malloc(asize);
if (p) {
struct alloc_hdr *h = p;
SRC_LOC_BT(bt);
alloc_insert_rcu(&bt.sl, h, size, h);
p = hdr2ptr(h);
if (ptr) {
struct alloc_hdr *old = ptr2hdr(ptr);
memcpy(p, ptr, old->size < size ? old->size : size);
free(ptr);
}
return p;
}
enomem:
errno = ENOMEM;
return 0;
}
struct dump_arg {
FILE *fp;
size_t min;
bool dump_csv;
};
char **bt_syms(void * const *addrlist, uint32_t size)
{
mwrap_assert(size < INT_MAX);
#if defined(__GLIBC__)
char **s = backtrace_symbols(addrlist, size);
#else /* make FreeBSD look like glibc output: */
char **s = backtrace_symbols_fmt(addrlist, size, "%f(%n%D) [%a]");
#endif
if (!s) perror("backtrace_symbols");
return s;
}
/* supported by modern gcc + clang */
#define AUTO_FREE __attribute__((__cleanup__(cleanup_free)))
static void cleanup_free(void *any)
{
void **p = any;
free(*p);
}
static void *write_csv(FILE *, size_t min, const char *sort, size_t sort_len);
static void *dump_to_file(struct dump_arg *a)
{
struct cds_lfht_iter iter;
struct src_loc *l;
struct cds_lfht *t;
if (a->dump_csv)
return write_csv(a->fp, a->min, NULL, 0);
++locating;
rcu_read_lock();
t = CMM_LOAD_SHARED(totals);
if (!t)
goto out_unlock;
cds_lfht_for_each_entry(t, &iter, l, hnode) {
if (l->total <= a->min) continue;
if (loc_is_addr(l)) {
AUTO_FREE char **s = bt_syms(l->bt, 1);
if (s)
fprintf(a->fp, "%16zu %12zu %s\n",
l->total, l->allocations, s[0]);
} else {
fprintf(a->fp, "%16zu %12zu %s:%u\n",
l->total, l->allocations, l->f->fn, l->lineno);
}
}
out_unlock:
rcu_read_unlock();
--locating;
return 0;
}
/* str = "/path/to/foo.so(+0x123) [0xdeadbeefcafe]" (see bt_syms()) */
static int extract_addr(const char *str, size_t len, void **p)
{
unsigned long x;
char *e;
const char *end = str + len;
const char *c = memrchr(str, '[', len);
if (c && (c + 2) < end && c[1] == '0' && c[2] == 'x') {
errno = 0;
x = strtoul(c + 3, &e, 16);
if (!errno && *e == ']') {
*p = (void *)x;
return 1;
}
}
return 0;
}
/* str is $PATHNAME:$LINENO, len is strlen(str) */
static struct src_loc *src_loc_lookup(const char *str, size_t len)
{
char *c = memrchr(str, ':', len);
const char *end = str + len;
unsigned lineno;
struct src_loc *l = NULL;
struct cds_lfht *t = CMM_LOAD_SHARED(files);
union stk_sf sf;
if (!c || c == end || !t)
return NULL;
size_t fn_len = c - str;
c++;
if (*c == '-') {
lineno = U24_MAX;
} else {
lineno = 0;
for (; c < end; c++) {
if (*c < '0' || *c > '9')
return NULL;
lineno *= 10;
lineno += (*c - '0');
}
if (lineno > U24_MAX)
return NULL;
}
rcu_read_lock();
struct src_file *f = src_file_get(t, &sf.sf, str, fn_len);
t = CMM_LOAD_SHARED(totals);
if (f && t) {
struct src_loc k;
k.f = f;
k.lineno = lineno;
k.bt_len = 0;
hash_src_loc(&k);
l = src_loc_get(t, &k);
}
rcu_read_unlock();
return l;
}
#ifndef O_CLOEXEC
# define O_CLOEXEC 0
#endif
static void h1d_atexit(void);
__attribute__ ((destructor)) static void mwrap_dtor(void)
{
const char *opt = getenv("MWRAP");
const char *modes[] = { "a", "a+", "w", "w+", "r+" };
struct dump_arg a = { .min = 0, .dump_csv = false };
size_t i;
int dump_fd;
char *dump_path;
char *s;
/* n.b. unsetenv("MWRAP") may be called, so run this unconditionally */
h1d_atexit();
if (!opt)
return;
++locating;
/* parse dump_csv:$PATHNAME */
if ((dump_path = strstr(opt, "dump_csv:"))) {
dump_path += sizeof("dump_csv");
if (!*dump_path)
dump_path = NULL;
else
a.dump_csv = true;
}
if (!dump_path) {
/* parse dump_path:$PATHNAME */
if ((dump_path = strstr(opt, "dump_path:"))) {
dump_path += sizeof("dump_path");
if (!*dump_path)
dump_path = NULL;
}
}
if (dump_path) {
char *end = strchr(dump_path, ',');
char buf[PATH_MAX];
AUTO_FREE char *pid_path = NULL;
if (end) {
mwrap_assert((end - dump_path) < (intptr_t)sizeof(buf));
end = mempcpy(buf, dump_path, end - dump_path);
*end = 0;
dump_path = buf;
}
/* %p => PID expansion (Linux core_pattern uses %p, too) */
if ((s = strchr(dump_path, '%')) && s[1] == 'p' &&
/* don't allow injecting extra formats: */
!strchr(s + 2, '%')) {
s[1] = 'd'; /* s/%p/%d/ to make asprintf happy */
int n = asprintf(&pid_path, dump_path, (int)getpid());
if (n < 0)
fprintf(stderr,
"asprintf failed: %m, dumping to %s\n",
dump_path);
else
dump_path = pid_path;
}
dump_fd = open(dump_path, O_CLOEXEC|O_WRONLY|O_APPEND|O_CREAT,
0666);
if (dump_fd < 0) {
fprintf(stderr, "open %s failed: %m\n", dump_path);
goto out;
}
} else {
s = strstr(opt, "dump_fd:");
if (!s)
goto out;
if (!sscanf(s, "dump_fd:%d", &dump_fd))
goto out;
}
/* allow dump_csv standalone for dump_fd */
if (!a.dump_csv && strstr(opt, "dump_csv"))
a.dump_csv = true;
if ((s = strstr(opt, "dump_min:")))
sscanf(s, "dump_min:%zu", &a.min);
switch (dump_fd) {
case 0: goto out;
case 1: a.fp = stdout; break;
case 2: a.fp = stderr; break;
default:
if (dump_fd < 0)
goto out;
a.fp = 0;
for (i = 0; !a.fp && i < 5; i++)
a.fp = fdopen(dump_fd, modes[i]);
if (!a.fp) {
fprintf(stderr, "failed to open fd=%d: %m\n", dump_fd);
goto out;
}
/* we'll leak some memory here, but this is a destructor */
}
dump_to_file(&a);
out:
--locating;
}
static void mwrap_reset(void)
{
struct cds_lfht *t;
struct cds_lfht_iter iter;
struct src_loc *l;
uatomic_set(&total_bytes_inc, 0);
uatomic_set(&total_bytes_dec, 0);
rcu_read_lock();
t = CMM_LOAD_SHARED(totals);
if (t)
cds_lfht_for_each_entry(t, &iter, l, hnode) {
uatomic_set(&l->total, 0);
uatomic_set(&l->allocations, 0);
uatomic_set(&l->frees, 0);
uatomic_set(&l->freed_bytes, 0);
uatomic_set(&l->age_total, 0);
uatomic_set(&l->max_lifespan, 0);
}
rcu_read_unlock();
}
static inline struct src_loc *mwrap_get(const char *str, size_t len)
{
void *p;
if (!extract_addr(str, len, &p))
return src_loc_lookup(str, len);
union stk_bt k;
struct cds_lfht *t = CMM_LOAD_SHARED(totals);
if (!t) return NULL;
k.sl.f = NULL;
k.sl.lineno = 0;
k.sl.bt[0] = p;
k.sl.bt_len = 1;
hash_src_loc(&k.sl);
rcu_read_lock();
struct src_loc *l = src_loc_get(t, &k.sl);
rcu_read_unlock();
return l;
}
static struct src_loc *mwrap_get_bin(const char *buf, size_t len)
{
static const size_t min_len = sizeof(struct src_file *) + SIZEOF_LINENO;
if (len >= min_len && ((len - min_len) % sizeof(void *)) == 0) {
struct cds_lfht *t = CMM_LOAD_SHARED(totals);
if (!t) return NULL;
union stk_bt k;
size_t bt_len = (len - min_len) / sizeof(void *);
if (bt_len > MWRAP_BT_MAX)
return NULL;
k.sl.bt_len = bt_len;
memcpy(src_loc_hash_tip(&k.sl), buf, len);
hash_src_loc(&k.sl);
rcu_read_lock();
struct src_loc *l = src_loc_get(t, &k.sl);
rcu_read_unlock();
return l;
}
return NULL;
}
static const char *mwrap_env;
#include "httpd.h"
__attribute__((constructor)) static void mwrap_ctor(void)
{
sigset_t set, old;
struct alloc_hdr *h;
mwrap_env = getenv("MWRAP");
++locating;
/* block signals */
CHECK(int, 0, sigfillset(&set));
CHECK(int, 0, pthread_sigmask(SIG_SETMASK, &set, &old));
ensure_initialization();
CHECK(int, 0, pthread_key_create(&tlskey, mstate_tsd_dtor));
/* initialize mutexes used by urcu-bp */
CMM_STORE_SHARED(files, lfht_new(256));
if (!CMM_LOAD_SHARED(files))
fprintf(stderr, "failed to allocate files table\n");
CMM_STORE_SHARED(totals, lfht_new(16384));
if (!CMM_LOAD_SHARED(totals))
fprintf(stderr, "failed to allocate totals table\n");
h = real_malloc(sizeof(struct alloc_hdr));
if (h) { /* force call_rcu to start background thread */
h->real = h;
call_rcu(&h->as.dead, free_hdr_rcu);
} else
perror("malloc");
h1d_start();
CHECK(int, 0, pthread_sigmask(SIG_SETMASK, &old, NULL));
CHECK(int, 0, pthread_atfork(atfork_prepare, atfork_parent,
atfork_child));
if (mwrap_env) {
const char *bt = strstr(mwrap_env, "bt:");
if (bt) {
bt += sizeof("bt");
errno = 0;
char *end;
unsigned long n = strtoul(bt, &end, 10);
if (n && !errno && (*end == ',' || *end == 0)) {
if (n > MWRAP_BT_MAX)
n = MWRAP_BT_MAX;
CMM_STORE_SHARED(bt_req_depth, (uint32_t)n);
}
}
}
--locating;
}
#if MWRAP_RUBY
# undef _GNU_SOURCE /* ruby.h redefines it */
# include <ruby.h> /* defines HAVE_RUBY_RACTOR_H on 3.0+ */
# include <ruby/thread.h>
# include <ruby/io.h>
# ifdef HAVE_RUBY_RACTOR_H /* Ruby 3.0+ */
extern MWRAP_TSD void * __attribute__((weak)) ruby_current_ec;
# else /* Ruby 2.6-2.7 */
extern void * __attribute__((weak)) ruby_current_execution_context_ptr;
# define ruby_current_ec ruby_current_execution_context_ptr
# endif /* HAVE_RUBY_RACTOR_H */
extern void * __attribute__((weak)) ruby_current_vm_ptr; /* for rb_gc_count */
extern size_t __attribute__((weak)) rb_gc_count(void);
int __attribute__((weak)) ruby_thread_has_gvl_p(void);
const char *rb_source_location_cstr(int *line); /* requires 2.6.0dev or later */
/*
* rb_source_location_cstr relies on GET_EC(), and it's possible
* to have a native thread but no EC during the early and late
* (teardown) phases of the Ruby process
*/
static int has_ec_p(void)
{
return ruby_thread_has_gvl_p && ruby_thread_has_gvl_p() &&
ruby_current_vm_ptr && ruby_current_ec;
}
static void mw_ruby_set_generation(size_t *gen, size_t size)
{
if (rb_gc_count) {
uatomic_add_return(&total_bytes_inc, size);
if (has_ec_p()) {
*gen = rb_gc_count();
uatomic_set(&last_gc_count, *gen);
}
} else {
*gen = uatomic_add_return(&total_bytes_inc, size);
}
}
static const char *mw_ruby_src_file_cstr(unsigned *lineno)
{
if (!has_ec_p()) return NULL;
int line;
const char *fn = rb_source_location_cstr(&line);
*lineno = line < 0 ? UINT_MAX : (unsigned)line;
return fn;
}
#endif /* !MWRAP_RUBY */
|