Hi Alex, On 18 June 2018 at 09:08, Alexander Graf <[email protected]> wrote: > On 06/18/2018 04:08 PM, Simon Glass wrote: >> >> From: Alexander Graf <[email protected]> >> >> The fs_read() function wants to get an address rather than the >> pointer to a buffer. >> >> So let's convert the passed buffer from pointer back a the address >> to make efi_loader on sandbox happier. >> >> Signed-off-by: Alexander Graf <[email protected]> >> Reviewed-by: Simon Glass <[email protected]> >> Signed-off-by: Simon Glass <[email protected]> >> --- >> >> 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 >> >> lib/efi_loader/efi_file.c | 5 ++++- >> 1 file changed, 4 insertions(+), 1 deletion(-) >> >> diff --git a/lib/efi_loader/efi_file.c b/lib/efi_loader/efi_file.c >> index e6a15bcb52..2107730ba5 100644 >> --- a/lib/efi_loader/efi_file.c >> +++ b/lib/efi_loader/efi_file.c >> @@ -9,6 +9,7 @@ >> #include <charset.h> >> #include <efi_loader.h> >> #include <malloc.h> >> +#include <mapmem.h> >> #include <fs.h> >> /* GUID for file system information */ >> @@ -232,8 +233,10 @@ static efi_status_t file_read(struct file_handle *fh, >> u64 *buffer_size, >> void *buffer) >> { >> loff_t actread; >> + /* fs_read expects buffer address, not pointer */ >> + uintptr_t buffer_addr = (uintptr_t)map_to_sysmem(buffer); > > > As you've seen with your patch on the stack based map_to_sysmem() > calculation, map_to_sysmem() really should only be used on pointers that we > are sure come from RAM. With EFI binaries, that isn't true because of the > stack, but it might be true due to other reasons too on real hardware, such > as direct read/write to/from flash. > > I think it's much safer to stay in pointer land once we passed the addr -> > ptr boundary. Going from ptr -> addr is usually a recipe for disaster.
We actually have no choice but to support this. As mentioned elsewhere addresses are the main currency in U-Boot and we should not look to convert it to use pointers. They are much less enjoyable to work with. The above patch is pretty simple. Regards, Simon _______________________________________________ U-Boot mailing list [email protected] https://lists.denx.de/listinfo/u-boot
