diff options
Diffstat (limited to 'kernels/linux-libre-xen/0007-x86-efi-Correct-EFI-boot-stub-use-of-code32_start.patch')
| -rw-r--r-- | kernels/linux-libre-xen/0007-x86-efi-Correct-EFI-boot-stub-use-of-code32_start.patch | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/kernels/linux-libre-xen/0007-x86-efi-Correct-EFI-boot-stub-use-of-code32_start.patch b/kernels/linux-libre-xen/0007-x86-efi-Correct-EFI-boot-stub-use-of-code32_start.patch new file mode 100644 index 000000000..898ee1543 --- /dev/null +++ b/kernels/linux-libre-xen/0007-x86-efi-Correct-EFI-boot-stub-use-of-code32_start.patch @@ -0,0 +1,110 @@ +From 720a9dbf61c88bd57d6f8198ed8ccb2bd4a6abd8 Mon Sep 17 00:00:00 2001 +From: Matt Fleming <matt@console-pimps.org> +Date: Wed, 9 Apr 2014 10:33:49 +0200 +Subject: [PATCH 07/10] x86/efi: Correct EFI boot stub use of code32_start +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +code32_start should point at the start of the protected mode code, and +*not* at the beginning of the bzImage. This is much easier to do in +assembly so document that callers of make_boot_params() need to fill out +code32_start. + +The fallout from this bug is that we would end up relocating the image +but copying the image at some offset, resulting in what appeared to be +memory corruption. + +Reported-by: Thomas Bächler <thomas@archlinux.org> +Signed-off-by: Matt Fleming <matt.fleming@intel.com> +--- + arch/x86/boot/compressed/eboot.c | 5 +++-- + arch/x86/boot/compressed/head_32.S | 14 ++++++++------ + arch/x86/boot/compressed/head_64.S | 9 +++------ + 3 files changed, 14 insertions(+), 14 deletions(-) + +diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c +index a7677ba..78cbb2d 100644 +--- a/arch/x86/boot/compressed/eboot.c ++++ b/arch/x86/boot/compressed/eboot.c +@@ -425,6 +425,9 @@ void setup_graphics(struct boot_params *boot_params) + * Because the x86 boot code expects to be passed a boot_params we + * need to create one ourselves (usually the bootloader would create + * one for us). ++ * ++ * The caller is responsible for filling out ->code32_start in the ++ * returned boot_params. + */ + struct boot_params *make_boot_params(void *handle, efi_system_table_t *_table) + { +@@ -483,8 +486,6 @@ struct boot_params *make_boot_params(void *handle, efi_system_table_t *_table) + hdr->vid_mode = 0xffff; + hdr->boot_flag = 0xAA55; + +- hdr->code32_start = (__u64)(unsigned long)image->image_base; +- + hdr->type_of_loader = 0x21; + + /* Convert unicode cmdline to ascii */ +diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S +index 9116aac..f45ab7a 100644 +--- a/arch/x86/boot/compressed/head_32.S ++++ b/arch/x86/boot/compressed/head_32.S +@@ -50,6 +50,13 @@ ENTRY(efi_pe_entry) + pushl %eax + pushl %esi + pushl %ecx ++ ++ call reloc ++reloc: ++ popl %ecx ++ subl reloc, %ecx ++ movl %ecx, BP_code32_start(%eax) ++ + sub $0x4, %esp + + ENTRY(efi_stub_entry) +@@ -63,12 +70,7 @@ ENTRY(efi_stub_entry) + hlt + jmp 1b + 2: +- call 3f +-3: +- popl %eax +- subl $3b, %eax +- subl BP_pref_address(%esi), %eax +- add BP_code32_start(%esi), %eax ++ movl BP_code32_start(%esi), %eax + leal preferred_addr(%eax), %eax + jmp *%eax + +diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S +index c5c1ae0..b10fa66 100644 +--- a/arch/x86/boot/compressed/head_64.S ++++ b/arch/x86/boot/compressed/head_64.S +@@ -217,6 +217,8 @@ ENTRY(efi_pe_entry) + cmpq $0,%rax + je 1f + mov %rax, %rdx ++ leaq startup_32(%rip), %rax ++ movl %eax, BP_code32_start(%rdx) + popq %rsi + popq %rdi + +@@ -230,12 +232,7 @@ ENTRY(efi_stub_entry) + hlt + jmp 1b + 2: +- call 3f +-3: +- popq %rax +- subq $3b, %rax +- subq BP_pref_address(%rsi), %rax +- add BP_code32_start(%esi), %eax ++ movl BP_code32_start(%esi), %eax + leaq preferred_addr(%rax), %rax + jmp *%rax + +-- +1.9.2 + |