+++ /dev/null
-/*
- * SPDX-License-Identifier: LGPL-2.1-or-later
- *
- * Copyright (C) 2009 Pierre-Marc Fournier
- * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- */
-
-/*
- * Do _not_ define _LGPL_SOURCE because we don't want to create a
- * circular dependency loop between this malloc wrapper, liburcu and
- * libc.
- */
-#include <ust-dlfcn.h>
-#include <sys/types.h>
-#include <stdio.h>
-#include <assert.h>
-#include <malloc.h>
-
-#include <urcu/system.h>
-#include <urcu/uatomic.h>
-#include <urcu/compiler.h>
-#include <urcu/tls-compat.h>
-#include <urcu/arch.h>
-
-#include <lttng/ust-libc-wrapper.h>
-
-#include <ust-helper.h>
-#include "ust-compat.h"
-
-#define TRACEPOINT_DEFINE
-#define TRACEPOINT_CREATE_PROBES
-#define TP_IP_PARAM ip
-#include "ust_libc.h"
-
-#define STATIC_CALLOC_LEN 4096
-static char static_calloc_buf[STATIC_CALLOC_LEN];
-static unsigned long static_calloc_buf_offset;
-
-struct alloc_functions {
- void *(*calloc)(size_t nmemb, size_t size);
- void *(*malloc)(size_t size);
- void (*free)(void *ptr);
- void *(*realloc)(void *ptr, size_t size);
- void *(*memalign)(size_t alignment, size_t size);
- int (*posix_memalign)(void **memptr, size_t alignment, size_t size);
-};
-
-static
-struct alloc_functions cur_alloc;
-
-/*
- * Make sure our own use of the LTS compat layer will not cause infinite
- * recursion by calling calloc.
- */
-
-static
-void *static_calloc(size_t nmemb, size_t size);
-
-/*
- * pthread mutex replacement for URCU tls compat layer.
- */
-static int ust_malloc_lock;
-
-static
-void ust_malloc_spin_lock(pthread_mutex_t *lock)
- __attribute__((unused));
-static
-void ust_malloc_spin_lock(pthread_mutex_t *lock __attribute__((unused)))
-{
- /*
- * The memory barrier within cmpxchg takes care of ordering
- * memory accesses with respect to the start of the critical
- * section.
- */
- while (uatomic_cmpxchg(&ust_malloc_lock, 0, 1) != 0)
- caa_cpu_relax();
-}
-
-static
-void ust_malloc_spin_unlock(pthread_mutex_t *lock)
- __attribute__((unused));
-static
-void ust_malloc_spin_unlock(pthread_mutex_t *lock __attribute__((unused)))
-{
- /*
- * Ensure memory accesses within the critical section do not
- * leak outside.
- */
- cmm_smp_mb();
- uatomic_set(&ust_malloc_lock, 0);
-}
-
-#define calloc static_calloc
-#define pthread_mutex_lock ust_malloc_spin_lock
-#define pthread_mutex_unlock ust_malloc_spin_unlock
-static DEFINE_URCU_TLS(int, malloc_nesting);
-#undef pthread_mutex_unlock
-#undef pthread_mutex_lock
-#undef calloc
-
-/*
- * Static allocator to use when initially executing dlsym(). It keeps a
- * size_t value of each object size prior to the object.
- */
-static
-void *static_calloc_aligned(size_t nmemb, size_t size, size_t alignment)
-{
- size_t prev_offset, new_offset, res_offset, aligned_offset;
-
- if (nmemb * size == 0) {
- return NULL;
- }
-
- /*
- * Protect static_calloc_buf_offset from concurrent updates
- * using a cmpxchg loop rather than a mutex to remove a
- * dependency on pthread. This will minimize the risk of bad
- * interaction between mutex and malloc instrumentation.
- */
- res_offset = CMM_LOAD_SHARED(static_calloc_buf_offset);
- do {
- prev_offset = res_offset;
- aligned_offset = LTTNG_UST_ALIGN(prev_offset + sizeof(size_t), alignment);
- new_offset = aligned_offset + nmemb * size;
- if (new_offset > sizeof(static_calloc_buf)) {
- abort();
- }
- } while ((res_offset = uatomic_cmpxchg(&static_calloc_buf_offset,
- prev_offset, new_offset)) != prev_offset);
- *(size_t *) &static_calloc_buf[aligned_offset - sizeof(size_t)] = size;
- return &static_calloc_buf[aligned_offset];
-}
-
-static
-void *static_calloc(size_t nmemb, size_t size)
-{
- void *retval;
-
- retval = static_calloc_aligned(nmemb, size, 1);
- return retval;
-}
-
-static
-void *static_malloc(size_t size)
-{
- void *retval;
-
- retval = static_calloc_aligned(1, size, 1);
- return retval;
-}
-
-static
-void static_free(void *ptr __attribute__((unused)))
-{
- /* no-op. */
-}
-
-static
-void *static_realloc(void *ptr, size_t size)
-{
- size_t *old_size = NULL;
- void *retval;
-
- if (size == 0) {
- retval = NULL;
- goto end;
- }
-
- if (ptr) {
- old_size = (size_t *) ptr - 1;
- if (size <= *old_size) {
- /* We can re-use the old entry. */
- *old_size = size;
- retval = ptr;
- goto end;
- }
- }
- /* We need to expand. Don't free previous memory location. */
- retval = static_calloc_aligned(1, size, 1);
- assert(retval);
- if (ptr)
- memcpy(retval, ptr, *old_size);
-end:
- return retval;
-}
-
-static
-void *static_memalign(size_t alignment, size_t size)
-{
- void *retval;
-
- retval = static_calloc_aligned(1, size, alignment);
- return retval;
-}
-
-static
-int static_posix_memalign(void **memptr, size_t alignment, size_t size)
-{
- void *ptr;
-
- /* Check for power of 2, larger than void *. */
- if (alignment & (alignment - 1)
- || alignment < sizeof(void *)
- || alignment == 0) {
- goto end;
- }
- ptr = static_calloc_aligned(1, size, alignment);
- *memptr = ptr;
-end:
- return 0;
-}
-
-static
-void setup_static_allocator(void)
-{
- assert(cur_alloc.calloc == NULL);
- cur_alloc.calloc = static_calloc;
- assert(cur_alloc.malloc == NULL);
- cur_alloc.malloc = static_malloc;
- assert(cur_alloc.free == NULL);
- cur_alloc.free = static_free;
- assert(cur_alloc.realloc == NULL);
- cur_alloc.realloc = static_realloc;
- assert(cur_alloc.memalign == NULL);
- cur_alloc.memalign = static_memalign;
- assert(cur_alloc.posix_memalign == NULL);
- cur_alloc.posix_memalign = static_posix_memalign;
-}
-
-static
-void lookup_all_symbols(void)
-{
- struct alloc_functions af;
-
- /*
- * Temporarily redirect allocation functions to
- * static_calloc_aligned, and free function to static_free
- * (no-op), until the dlsym lookup has completed.
- */
- setup_static_allocator();
-
- /* Perform the actual lookups */
- af.calloc = dlsym(RTLD_NEXT, "calloc");
- af.malloc = dlsym(RTLD_NEXT, "malloc");
- af.free = dlsym(RTLD_NEXT, "free");
- af.realloc = dlsym(RTLD_NEXT, "realloc");
- af.memalign = dlsym(RTLD_NEXT, "memalign");
- af.posix_memalign = dlsym(RTLD_NEXT, "posix_memalign");
-
- /* Populate the new allocator functions */
- memcpy(&cur_alloc, &af, sizeof(cur_alloc));
-}
-
-void *malloc(size_t size)
-{
- void *retval;
-
- URCU_TLS(malloc_nesting)++;
- if (cur_alloc.malloc == NULL) {
- lookup_all_symbols();
- if (cur_alloc.malloc == NULL) {
- fprintf(stderr, "mallocwrap: unable to find malloc\n");
- abort();
- }
- }
- retval = cur_alloc.malloc(size);
- if (URCU_TLS(malloc_nesting) == 1) {
- tracepoint(lttng_ust_libc, malloc,
- size, retval, LTTNG_UST_CALLER_IP());
- }
- URCU_TLS(malloc_nesting)--;
- return retval;
-}
-
-void free(void *ptr)
-{
- URCU_TLS(malloc_nesting)++;
- /*
- * Check whether the memory was allocated with
- * static_calloc_align, in which case there is nothing to free.
- */
- if (caa_unlikely((char *)ptr >= static_calloc_buf &&
- (char *)ptr < static_calloc_buf + STATIC_CALLOC_LEN)) {
- goto end;
- }
-
- if (URCU_TLS(malloc_nesting) == 1) {
- tracepoint(lttng_ust_libc, free,
- ptr, LTTNG_UST_CALLER_IP());
- }
-
- if (cur_alloc.free == NULL) {
- lookup_all_symbols();
- if (cur_alloc.free == NULL) {
- fprintf(stderr, "mallocwrap: unable to find free\n");
- abort();
- }
- }
- cur_alloc.free(ptr);
-end:
- URCU_TLS(malloc_nesting)--;
-}
-
-void *calloc(size_t nmemb, size_t size)
-{
- void *retval;
-
- URCU_TLS(malloc_nesting)++;
- if (cur_alloc.calloc == NULL) {
- lookup_all_symbols();
- if (cur_alloc.calloc == NULL) {
- fprintf(stderr, "callocwrap: unable to find calloc\n");
- abort();
- }
- }
- retval = cur_alloc.calloc(nmemb, size);
- if (URCU_TLS(malloc_nesting) == 1) {
- tracepoint(lttng_ust_libc, calloc,
- nmemb, size, retval, LTTNG_UST_CALLER_IP());
- }
- URCU_TLS(malloc_nesting)--;
- return retval;
-}
-
-void *realloc(void *ptr, size_t size)
-{
- void *retval;
-
- URCU_TLS(malloc_nesting)++;
- /*
- * Check whether the memory was allocated with
- * static_calloc_align, in which case there is nothing
- * to free, and we need to copy the old data.
- */
- if (caa_unlikely((char *)ptr >= static_calloc_buf &&
- (char *)ptr < static_calloc_buf + STATIC_CALLOC_LEN)) {
- size_t *old_size;
-
- old_size = (size_t *) ptr - 1;
- if (cur_alloc.calloc == NULL) {
- lookup_all_symbols();
- if (cur_alloc.calloc == NULL) {
- fprintf(stderr, "reallocwrap: unable to find calloc\n");
- abort();
- }
- }
- retval = cur_alloc.calloc(1, size);
- if (retval) {
- memcpy(retval, ptr, *old_size);
- }
- /*
- * Mimick that a NULL pointer has been received, so
- * memory allocation analysis based on the trace don't
- * get confused by the address from the static
- * allocator.
- */
- ptr = NULL;
- goto end;
- }
-
- if (cur_alloc.realloc == NULL) {
- lookup_all_symbols();
- if (cur_alloc.realloc == NULL) {
- fprintf(stderr, "reallocwrap: unable to find realloc\n");
- abort();
- }
- }
- retval = cur_alloc.realloc(ptr, size);
-end:
- if (URCU_TLS(malloc_nesting) == 1) {
- tracepoint(lttng_ust_libc, realloc,
- ptr, size, retval, LTTNG_UST_CALLER_IP());
- }
- URCU_TLS(malloc_nesting)--;
- return retval;
-}
-
-void *memalign(size_t alignment, size_t size)
-{
- void *retval;
-
- URCU_TLS(malloc_nesting)++;
- if (cur_alloc.memalign == NULL) {
- lookup_all_symbols();
- if (cur_alloc.memalign == NULL) {
- fprintf(stderr, "memalignwrap: unable to find memalign\n");
- abort();
- }
- }
- retval = cur_alloc.memalign(alignment, size);
- if (URCU_TLS(malloc_nesting) == 1) {
- tracepoint(lttng_ust_libc, memalign,
- alignment, size, retval,
- LTTNG_UST_CALLER_IP());
- }
- URCU_TLS(malloc_nesting)--;
- return retval;
-}
-
-int posix_memalign(void **memptr, size_t alignment, size_t size)
-{
- int retval;
-
- URCU_TLS(malloc_nesting)++;
- if (cur_alloc.posix_memalign == NULL) {
- lookup_all_symbols();
- if (cur_alloc.posix_memalign == NULL) {
- fprintf(stderr, "posix_memalignwrap: unable to find posix_memalign\n");
- abort();
- }
- }
- retval = cur_alloc.posix_memalign(memptr, alignment, size);
- if (URCU_TLS(malloc_nesting) == 1) {
- tracepoint(lttng_ust_libc, posix_memalign,
- *memptr, alignment, size,
- retval, LTTNG_UST_CALLER_IP());
- }
- URCU_TLS(malloc_nesting)--;
- return retval;
-}
-
-static
-void lttng_ust_fixup_malloc_nesting_tls(void)
-{
- asm volatile ("" : : "m" (URCU_TLS(malloc_nesting)));
-}
-
-void lttng_ust_libc_wrapper_malloc_init(void)
-{
- /* Initialization already done */
- if (cur_alloc.calloc) {
- return;
- }
- lttng_ust_fixup_malloc_nesting_tls();
- /*
- * Ensure the allocator is in place before the process becomes
- * multithreaded.
- */
- lookup_all_symbols();
-}
projects / lttng-ust.git / blobdiff