From: Simon Glass Date: Sat, 15 Sep 2018 06:50:54 +0000 (-0600) Subject: sandbox: Align RAM buffer to the machine page size X-Git-Tag: v2018.11-rc1~82^2~27 X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=613185023f0e84c410a2c088dd030ca696834763;p=oweals%2Fu-boot.git sandbox: Align RAM buffer to the machine page size At present the sandbox RAM buffer is not aligned to any particular address boundary. This makes the internal pointers somewhat random with respect to the associated RAM buffer addresses. Align the buffer to the page size of the machine to help with this. Note that there is a header at the start of the allocated pointer. To avoid returning a pointer which is not aligned to a page boundary, we waste almost an entire page of memory for each allocation. Signed-off-by: Simon Glass Signed-off-by: Alexander Graf --- diff --git a/arch/sandbox/cpu/os.c b/arch/sandbox/cpu/os.c index 5839932b00..a1a982af2d 100644 --- a/arch/sandbox/cpu/os.c +++ b/arch/sandbox/cpu/os.c @@ -143,14 +143,15 @@ void os_tty_raw(int fd, bool allow_sigs) void *os_malloc(size_t length) { struct os_mem_hdr *hdr; + int page_size = getpagesize(); - hdr = mmap(NULL, length + sizeof(*hdr), PROT_READ | PROT_WRITE, - MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + hdr = mmap(NULL, length + page_size, + PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); if (hdr == MAP_FAILED) return NULL; hdr->length = length; - return hdr + 1; + return (void *)hdr + page_size; } void os_free(void *ptr)