diff options
| author | Ard Biesheuvel <ardb@kernel.org> | 2020-03-29 11:05:43 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2020-03-29 13:08:18 +0300 |
| commit | c2136dceba9a329e997ccce3277d2084e21a8a04 (patch) | |
| tree | a560bcf2ee5d19f1f5cf2be1f920af77f163e05b /drivers/firmware | |
| parent | d5528d5e91041e68e8eab9792ce627705a0ed273 (diff) | |
| download | linux-c2136dceba9a329e997ccce3277d2084e21a8a04.tar.xz | |
efi/libstub/arm64: Avoid image_base value from efi_loaded_image
Commit:
9f9223778ef3 ("efi/libstub/arm: Make efi_entry() an ordinary PE/COFF entrypoint")
did some code refactoring to get rid of the EFI entry point assembler
code, and in the process, it got rid of the assignment of image_addr
to the value of _text. Instead, it switched to using the image_base
field of the efi_loaded_image struct provided by UEFI, which should
contain the same value.
However, Michael reports that this is not the case: older GRUB builds
corrupt this value in some way, and since we can easily switch back to
referring to _text to discover this value, let's simply do that.
While at it, fix another issue in commit 9f9223778ef3, which may result
in the unassigned image_addr to be misidentified as the preferred load
offset of the kernel, which is unlikely but will cause a boot crash if
it does occur.
Finally, let's add a warning if the _text vs. image_base discrepancy is
detected, so we can tell more easily how widespread this issue actually
is.
Reported-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-efi@vger.kernel.org
Diffstat (limited to 'drivers/firmware')
| -rw-r--r-- | drivers/firmware/efi/libstub/arm64-stub.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c index 9254cd8ab2d3..db0c1a9c1699 100644 --- a/drivers/firmware/efi/libstub/arm64-stub.c +++ b/drivers/firmware/efi/libstub/arm64-stub.c @@ -116,6 +116,7 @@ efi_status_t handle_kernel_image(unsigned long *image_addr, * Mustang), we can still place the kernel at the address * 'dram_base + TEXT_OFFSET'. */ + *image_addr = (unsigned long)_text; if (*image_addr == preferred_offset) return EFI_SUCCESS; @@ -140,7 +141,11 @@ efi_status_t handle_kernel_image(unsigned long *image_addr, } *image_addr = *reserve_addr + TEXT_OFFSET; } - memcpy((void *)*image_addr, image->image_base, kernel_size); + + if (image->image_base != _text) + pr_efi_err("FIRMWARE BUG: efi_loaded_image_t::image_base has bogus value\n"); + + memcpy((void *)*image_addr, _text, kernel_size); return EFI_SUCCESS; } |