From 89893f9a2468575e78eef64e8f6a2628034e9c56 Mon Sep 17 00:00:00 2001 From: Dale Weiler Date: Fri, 16 Aug 2013 07:22:01 +0000 Subject: [PATCH] Valgrind integration for our memory allocator. --- Makefile | 2 ++ stat.c | 100 +++++++++++++++++++++++++++++++++++++++++++++++++++---- 2 files changed, 95 insertions(+), 7 deletions(-) diff --git a/Makefile b/Makefile index 6ba6a34..c174b91 100644 --- a/Makefile +++ b/Makefile @@ -55,6 +55,7 @@ ifneq ("$(CYGWIN)", "") GMQCC = gmqcc.exe TESTSUITE = testsuite.exe PAK = gmqpak.exe + CFLAGS += -DNVALGRIND else ifneq ("$(MINGW)", "") #nullify the common variables that @@ -67,6 +68,7 @@ ifneq ("$(MINGW)", "") GMQCC = gmqcc.exe TESTSUITE = testsuite.exe PAK = gmqpak.exe + CFLAGS += -DNVALGRIND else QCVM = qcvm GMQCC = gmqcc diff --git a/stat.c b/stat.c index efe234e..ffb5b22 100644 --- a/stat.c +++ b/stat.c @@ -27,6 +27,22 @@ #include "gmqcc.h" +/* + * For the valgrind integration of our allocator. This allows us to have + * more `accurate` valgrind output for our allocator, and also secures the + * possible underflows (where one could obtain access to the redzone that + * represents info about that allocation). + */ +#ifndef NVALGRIND +# include +# include +#else +# define VALGRIND_MALLOCLIKE_BLOCK(PTR, ALLOC_SIZE, REDZONE_SIZE, ZEROED) +# define VALGRIND_FREELIKE_BLOCK(PTR, REDZONE_SIZE) +# define VALGRIND_MAKE_MEM_DEFINED(PTR, REDZONE_SIZE) +# define VALGRIND_MAKE_MEM_NOACCESS(PTR, REDZONE_SIZE) +#endif + /* * GMQCC performs tons of allocations, constructions, and crazyness * all around. When trying to optimizes systems, or just get fancy @@ -116,9 +132,12 @@ void *stat_mem_allocate(size_t size, size_t line, const char *file) { info->prev = NULL; info->next = stat_mem_block_root; - /* unlikely since it only happens once */ - if (GMQCC_UNLIKELY(stat_mem_block_root != NULL)) + /* likely since it only happens once */ + if (GMQCC_LIKELY(stat_mem_block_root != NULL)) { + VALGRIND_MAKE_MEM_DEFINED(stat_mem_block_root, sizeof(stat_mem_block_t)); stat_mem_block_root->prev = info; + VALGRIND_MAKE_MEM_NOACCESS(stat_mem_block_root, sizeof(stat_mem_block_t)); + } stat_mem_block_root = info; stat_mem_allocated += size; @@ -128,6 +147,7 @@ void *stat_mem_allocate(size_t size, size_t line, const char *file) { if (stat_mem_high > stat_mem_peak) stat_mem_peak = stat_mem_high; + VALGRIND_MALLOCLIKE_BLOCK(data, size, sizeof(stat_mem_block_t), 0); return data; } @@ -139,18 +159,38 @@ void stat_mem_deallocate(void *ptr) { info = ((stat_mem_block_t*)ptr - 1); + /* + * we need access to the redzone that represents the info block + * so lets do that. + */ + VALGRIND_MAKE_MEM_DEFINED(info, sizeof(stat_mem_block_t)); + stat_mem_deallocated += info->size; stat_mem_high -= info->size; stat_mem_deallocated_total ++; - if (info->prev) info->prev->next = info->next; - if (info->next) info->next->prev = info->prev; + if (info->prev) { + /* just need access for a short period */ + VALGRIND_MAKE_MEM_DEFINED(info->prev, sizeof(stat_mem_block_t)); + info->prev->next = info->next; + /* don't need access anymore */ + VALGRIND_MAKE_MEM_NOACCESS(info->prev, sizeof(stat_mem_block_t)); + } + if (info->next) { + /* just need access for a short period */ + VALGRIND_MAKE_MEM_DEFINED(info->next, sizeof(stat_mem_block_t)); + info->next->prev = info->prev; + /* don't need access anymore */ + VALGRIND_MAKE_MEM_NOACCESS(info->next, sizeof(stat_mem_block_t)); + } /* move ahead */ if (info == stat_mem_block_root) stat_mem_block_root = info->next; free(info); + VALGRIND_MAKE_MEM_NOACCESS(info, sizeof(stat_mem_block_t)); + VALGRIND_FREELIKE_BLOCK(ptr, sizeof(stat_mem_block_t)); } void *stat_mem_reallocate(void *ptr, size_t size, size_t line, const char *file) { @@ -174,15 +214,36 @@ void *stat_mem_reallocate(void *ptr, size_t size, size_t line, const char *file) return NULL; } + VALGRIND_MALLOCLIKE_BLOCK(newinfo + 1, size, sizeof(stat_mem_block_t), 0); + + /* we need access to the old info redzone */ + VALGRIND_MAKE_MEM_DEFINED(oldinfo, sizeof(stat_mem_block_t)); + memcpy(newinfo+1, oldinfo+1, oldinfo->size); - if (oldinfo->prev) oldinfo->prev->next = oldinfo->next; - if (oldinfo->next) oldinfo->next->prev = oldinfo->prev; + if (oldinfo->prev) { + /* just need access for a short period */ + VALGRIND_MAKE_MEM_DEFINED(oldinfo->prev, sizeof(stat_mem_block_t)); + oldinfo->prev->next = oldinfo->next; + /* don't need access anymore */ + VALGRIND_MAKE_MEM_NOACCESS(oldinfo->prev, sizeof(stat_mem_block_t)); + } + + if (oldinfo->next) { + /* just need access for a short period */ + VALGRIND_MAKE_MEM_DEFINED(oldinfo->next, sizeof(stat_mem_block_t)); + oldinfo->next->prev = oldinfo->prev; + /* don't need access anymore */ + VALGRIND_MAKE_MEM_NOACCESS(oldinfo->next, sizeof(stat_mem_block_t)); + } /* move ahead */ if (oldinfo == stat_mem_block_root) stat_mem_block_root = oldinfo->next; + /* we need access to the redzone for the newinfo block */ + VALGRIND_MAKE_MEM_DEFINED(newinfo, sizeof(stat_mem_block_t)); + newinfo->line = line; newinfo->size = size; newinfo->file = file; @@ -193,8 +254,13 @@ void *stat_mem_reallocate(void *ptr, size_t size, size_t line, const char *file) * likely since the only time there is no root is when it's * being initialized first. */ - if (GMQCC_LIKELY(stat_mem_block_root != NULL)) + if (GMQCC_LIKELY(stat_mem_block_root != NULL)) { + /* we need access to the root */ + VALGRIND_MAKE_MEM_DEFINED(stat_mem_block_root, sizeof(stat_mem_block_t)); stat_mem_block_root->prev = newinfo; + /* kill access */ + VALGRIND_MAKE_MEM_NOACCESS(stat_mem_block_root, sizeof(stat_mem_block_t)); + } stat_mem_block_root = newinfo; stat_mem_allocated -= oldinfo->size; @@ -202,10 +268,18 @@ void *stat_mem_reallocate(void *ptr, size_t size, size_t line, const char *file) stat_mem_allocated += newinfo->size; stat_mem_high += newinfo->size; + /* + * we're finished with the redzones, lets kill the access + * to them. + */ + VALGRIND_MAKE_MEM_NOACCESS(newinfo, sizeof(stat_mem_block_t)); + VALGRIND_MAKE_MEM_NOACCESS(oldinfo, sizeof(stat_mem_block_t)); + if (stat_mem_high > stat_mem_peak) stat_mem_peak = stat_mem_high; free(oldinfo); + VALGRIND_FREELIKE_BLOCK(ptr, sizeof(stat_mem_block_t)); return newinfo + 1; } @@ -631,7 +705,11 @@ static void stat_dump_mem_contents(stat_mem_block_t *memory, uint16_t cols) { static void stat_dump_mem_leaks(void) { stat_mem_block_t *info; + /* we need access to the root for this */ + VALGRIND_MAKE_MEM_DEFINED(stat_mem_block_root, sizeof(stat_mem_block_t)); for (info = stat_mem_block_root; info; info = info->next) { + /* we need access to the block */ + VALGRIND_MAKE_MEM_DEFINED(info, sizeof(stat_mem_block_t)); con_out("lost: %u (bytes) at %s:%u\n", info->size, info->file, @@ -639,7 +717,15 @@ static void stat_dump_mem_leaks(void) { ); stat_dump_mem_contents(info, OPTS_OPTION_U16(OPTION_MEMDUMPCOLS)); + + /* + * we're finished with the access, the redzone should be marked + * inaccesible so that invalid read/writes that could 'step-into' + * those redzones will show up as invalid read/writes in valgrind. + */ + VALGRIND_MAKE_MEM_NOACCESS(info, sizeof(stat_mem_block_t)); } + VALGRIND_MAKE_MEM_NOACCESS(stat_mem_block_root, sizeof(stat_mem_block_t)); } static void stat_dump_mem_info(void) { -- 2.39.2