| Message ID | 20180808095433.230882-10-sjg@chromium.org |
|---|---|
| State | Superseded, archived |
| Delegated to: | Alexander Graf |
| Headers | show |
| Series | efi: Enable sandbox support for EFI loader | expand |
On 08.08.18 11:54, Simon Glass wrote: > 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. Please describe in the patch description that you pad the cookie that os_malloc writes to a page boundary. It's pretty hard to grasp that from the current patch description :) Alex > > Signed-off-by: Simon Glass <sjg@chromium.org> > --- > > Changes in v9: None > Changes in v8: None > Changes in v7: None > Changes in v6: None > Changes in v5: None > Changes in v4: None > Changes in v3: None > Changes in v2: None > > arch/sandbox/cpu/os.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/arch/sandbox/cpu/os.c b/arch/sandbox/cpu/os.c > index 5839932b005..a1a982af2de 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) >
diff --git a/arch/sandbox/cpu/os.c b/arch/sandbox/cpu/os.c index 5839932b005..a1a982af2de 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)
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. Signed-off-by: Simon Glass <sjg@chromium.org> --- Changes in v9: None Changes in v8: None Changes in v7: None Changes in v6: None Changes in v5: None Changes in v4: None Changes in v3: None Changes in v2: None arch/sandbox/cpu/os.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)