On 18.01.18 19:28, Heinrich Schuchardt wrote:
On 01/18/2018 11:05 AM, Alexander Graf wrote:
On 18.01.18 10:52, Heinrich Schuchardt wrote:
On 01/18/2018 10:24 AM, Alexander Graf wrote:
On 18.01.18 08:24, Heinrich Schuchardt wrote:
Avoid a failed assertion when an EFI app calls an EFI app.
Avoid that the indent level increases when calling 'bootefi hello' repeatedly.
Avoid negative indent level when an EFI app calls an EFI app that calls an EFI app (e.g. iPXE loads grub which starts the kernel).
Return the status code of a loaded image that returns without calling the Exit boot service.
Signed-off-by: Heinrich Schuchardt xypron.glpk@gmx.de
lib/efi_loader/efi_boottime.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-)
diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c index 2c5499e0c8..538cc55d20 100644 --- a/lib/efi_loader/efi_boottime.c +++ b/lib/efi_loader/efi_boottime.c @@ -1537,6 +1537,7 @@ static efi_status_t EFIAPI efi_start_image(efi_handle_t image_handle, asmlinkage ulong (*entry)(efi_handle_t image_handle, struct efi_system_table *st); struct efi_loaded_image *info = image_handle; + efi_status_t ret; EFI_ENTRY("%p, %p, %p", image_handle, exit_data_size, exit_data); entry = info->reserved; @@ -1546,17 +1547,23 @@ static efi_status_t EFIAPI efi_start_image(efi_handle_t image_handle, /* call the image! */ if (setjmp(&info->exit_jmp)) { /* We returned from the child image */ +#ifdef CONFIG_ARM + /* efi_exit() called efi_restore_gd() */ + gd = app_gd; +#endif + /* Execute the return part of EFI_CALL */ + assert(__efi_entry_check()); + debug("%sEFI: %lu returned by started image\n", + __efi_nesting_dec(),
I don't understand why you need to decrease the nesting level here after the other rework. You're now calling EFI_ENTRY/EFI_EXIT in all normal paths when going in/out of an application, no?
bootefi -> level 0 ** EFI application running at level 0 LoadImage EFI_ENTRY -> level 1 LoadImage EFI_EXIT -> level 0 ** EFI application running at level 0
-- base level at 0
StartImage EFI_ENTRY -> level 1
This is decreased in EFI_EXIT of StartImage
StartImage EFI_CALL -> level 2
This is the one that needs manual decrease then?
Exit EFI_ENTRY -> level 3
Gets decreased right below in Exit again
Exit EFI_EXIT -> level 2 longjmp -> level 2 __efi_nesting_dec() -> level 1 StartImage EFI_EXIT -> level 0
--- base level again
So I guess the problem is that we never get into the second half of EFI_CALL when ->exit() gets called because of the longjmp.
Can you please add a comment explaining that rationale with a hint to EFI_CALL and that all we do is execute the lower half of it manually again because it got interrupted by the longjmp?
I already wrote: /* Execute the return part of EFI_CALL */
Could you make that slightly more verbose? Which EFI_CALL? Why do we need to execute the return path?
Keep in mind that people 2 years down the road should be able to grasp what the code does :).
Alex