diff options
| author | Arvind Sankar <nivedita@alum.mit.edu> | 2020-03-08 09:08:47 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2020-03-08 09:58:19 +0100 |
| commit | 1887c9b653f99577c0f8ec413b0921a32b6129e2 (patch) | |
| tree | a6a31605952088bd1a3aeceab795d0d96e980153 /drivers/firmware | |
| parent | 8ef44be393113dca5cece65bc142ebb8ef013af0 (diff) | |
| download | linux-1887c9b653f99577c0f8ec413b0921a32b6129e2.tar.bz2 | |
efi/x86: Decompress at start of PE image load address
When booted via PE loader, define image_offset to hold the offset of
startup_32() from the start of the PE image, and use it as the start of
the decompression buffer.
[ mingo: Fixed the grammar in the comments. ]
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200303221205.4048668-3-nivedita@alum.mit.edu
Link: https://lore.kernel.org/r/20200308080859.21568-17-ardb@kernel.org
Diffstat (limited to 'drivers/firmware')
| -rw-r--r-- | drivers/firmware/efi/libstub/x86-stub.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c index 69a942f0640b..3e1bc8a370be 100644 --- a/drivers/firmware/efi/libstub/x86-stub.c +++ b/drivers/firmware/efi/libstub/x86-stub.c @@ -19,6 +19,7 @@ static efi_system_table_t *sys_table; extern const bool efi_is64; +extern u32 image_offset; __pure efi_system_table_t *efi_system_table(void) { @@ -365,6 +366,7 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle, struct boot_params *boot_params; struct setup_header *hdr; efi_loaded_image_t *image; + void *image_base; efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID; int options_size = 0; efi_status_t status; @@ -385,7 +387,10 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle, efi_exit(handle, status); } - hdr = &((struct boot_params *)efi_table_attr(image, image_base))->hdr; + image_base = efi_table_attr(image, image_base); + image_offset = (void *)startup_32 - image_base; + + hdr = &((struct boot_params *)image_base)->hdr; above4g = hdr->xloadflags & XLF_CAN_BE_LOADED_ABOVE_4G; status = efi_allocate_pages(0x4000, (unsigned long *)&boot_params, @@ -400,7 +405,7 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle, hdr = &boot_params->hdr; /* Copy the second sector to boot_params */ - memcpy(&hdr->jump, efi_table_attr(image, image_base) + 512, 512); + memcpy(&hdr->jump, image_base + 512, 512); /* * Fill out some of the header fields ourselves because the @@ -727,7 +732,7 @@ unsigned long efi_main(efi_handle_t handle, * If the kernel isn't already loaded at the preferred load * address, relocate it. */ - if (bzimage_addr != hdr->pref_address) { + if (bzimage_addr - image_offset != hdr->pref_address) { status = efi_relocate_kernel(&bzimage_addr, hdr->init_size, hdr->init_size, hdr->pref_address, @@ -737,6 +742,12 @@ unsigned long efi_main(efi_handle_t handle, efi_printk("efi_relocate_kernel() failed!\n"); goto fail; } + /* + * Now that we've copied the kernel elsewhere, we no longer + * have a set up block before startup_32(), so reset image_offset + * to zero in case it was set earlier. + */ + image_offset = 0; } /* |