From 8f896b14d32cb338bb18489f3503eedd189c2dc4 Mon Sep 17 00:00:00 2001 From: Aidan MacDonald Date: Wed, 30 Mar 2022 20:55:14 +0100 Subject: buflib: remove the 'name' member from union buflib_data Using a length 1 char array to point to the name buffer triggers a -Warray-bounds warning from GCC when fortified strcpy is used. This type of construct isn't safe in general -- if the compiler makes assumptions based on the array bound it can create subtle bugs when accessing the array out of bounds. Instead, add a function get_block_name() which returns a pointer to the name field by casting. This suppresses the warning and it should be a bit more portable. Change-Id: I25d4f46f799022ad0ec23bef0218f7595cc741ea --- firmware/buflib.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'firmware/buflib.c') diff --git a/firmware/buflib.c b/firmware/buflib.c index 6bfc499235..5cdb0f7ecd 100644 --- a/firmware/buflib.c +++ b/firmware/buflib.c @@ -187,6 +187,11 @@ static void check_block_crc(struct buflib_context *ctx, union buflib_data *block, union buflib_data *block_end); +static inline char* get_block_name(union buflib_data *block) +{ + return (char*)&block[fidx_NAME]; +} + /* Initialize buffer manager */ void buflib_init(struct buflib_context *ctx, void *buf, size_t size) @@ -378,7 +383,7 @@ move_block(struct buflib_context* ctx, union buflib_data* block, int shift) int handle = ctx->handle_table - h_entry; BDEBUGF("%s(): moving \"%s\"(id=%d) by %d(%d)\n", __func__, - block[fidx_NAME].name, handle, shift, shift*(int)sizeof(union buflib_data)); + get_block_name(block), handle, shift, shift*(int)sizeof(union buflib_data)); new_block = block + shift; new_start = h_entry->alloc + shift*sizeof(union buflib_data); @@ -726,7 +731,7 @@ buffer_alloc: block[fidx_HANDLE].handle = handle; block[fidx_OPS].ops = ops; if (name_len > 0) - strcpy(block[fidx_NAME].name, name); + strcpy(get_block_name(block), name); size_t bsize = BUFLIB_NUM_FIELDS + name_len/sizeof(union buflib_data); union buflib_data *block_end = block + bsize; @@ -1037,7 +1042,7 @@ const char* buflib_get_name(struct buflib_context *ctx, int handle) return NULL; data -= len; - return data[fidx_NAME].name; + return get_block_name(data); } #ifdef DEBUG @@ -1095,7 +1100,7 @@ void buflib_print_block_at(struct buflib_context *ctx, int block_num, { snprintf(buf, bufsize, "%8p: val: %4ld (%s)", block, (long)block->val, - block->val > 0 ? block[fidx_NAME].name : ""); + block->val > 0 ? get_block_name(block) : ""); } } } -- cgit v1.2.3