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authorArd Biesheuvel <ardb@kernel.org>2023-09-15 20:16:31 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-02-23 11:25:27 +0300
commitf7eedad780689ebd4ba93b9ef5e90048e7ff3c2e (patch)
tree262e04a24c25dec6fd2dd85b1cb4eebe8b118d4c /arch/x86
parent476316bb48c1eea1ad1d317615f715f8d067166d (diff)
downloadlinux-f7eedad780689ebd4ba93b9ef5e90048e7ff3c2e.tar.xz
x86/boot: Split off PE/COFF .data section
commit 34951f3c28bdf6481d949a20413b2ce7693687b2 upstream. Describe the code and data of the decompressor binary using separate .text and .data PE/COFF sections, so that we will be able to map them using restricted permissions once we increase the section and file alignment sufficiently. This avoids the need for memory mappings that are writable and executable at the same time, which is something that is best avoided for security reasons. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230915171623.655440-17-ardb@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/boot/Makefile2
-rw-r--r--arch/x86/boot/header.S19
2 files changed, 16 insertions, 5 deletions
diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile
index cc04917b1ac6..3cece19b7473 100644
--- a/arch/x86/boot/Makefile
+++ b/arch/x86/boot/Makefile
@@ -89,7 +89,7 @@ $(obj)/vmlinux.bin: $(obj)/compressed/vmlinux FORCE
SETUP_OBJS = $(addprefix $(obj)/,$(setup-y))
-sed-zoffset := -e 's/^\([0-9a-fA-F]*\) [a-zA-Z] \(startup_32\|efi.._stub_entry\|efi\(32\)\?_pe_entry\|input_data\|kernel_info\|_end\|_ehead\|_text\|_edata\|z_.*\)$$/\#define ZO_\2 0x\1/p'
+sed-zoffset := -e 's/^\([0-9a-fA-F]*\) [a-zA-Z] \(startup_32\|efi.._stub_entry\|efi\(32\)\?_pe_entry\|input_data\|kernel_info\|_end\|_ehead\|_text\|_e\?data\|z_.*\)$$/\#define ZO_\2 0x\1/p'
quiet_cmd_zoffset = ZOFFSET $@
cmd_zoffset = $(NM) $< | sed -n $(sed-zoffset) > $@
diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
index 9e9641e220a7..a1f986105f00 100644
--- a/arch/x86/boot/header.S
+++ b/arch/x86/boot/header.S
@@ -75,9 +75,9 @@ optional_header:
.byte 0x02 # MajorLinkerVersion
.byte 0x14 # MinorLinkerVersion
- .long setup_size + ZO__end - 0x200 # SizeOfCode
+ .long ZO__data # SizeOfCode
- .long 0 # SizeOfInitializedData
+ .long ZO__end - ZO__data # SizeOfInitializedData
.long 0 # SizeOfUninitializedData
.long setup_size + ZO_efi_pe_entry # AddressOfEntryPoint
@@ -178,9 +178,9 @@ section_table:
.byte 0
.byte 0
.byte 0
- .long ZO__end
+ .long ZO__data
.long setup_size
- .long ZO__edata # Size of initialized data
+ .long ZO__data # Size of initialized data
# on disk
.long setup_size
.long 0 # PointerToRelocations
@@ -191,6 +191,17 @@ section_table:
IMAGE_SCN_MEM_READ | \
IMAGE_SCN_MEM_EXECUTE # Characteristics
+ .ascii ".data\0\0\0"
+ .long ZO__end - ZO__data # VirtualSize
+ .long setup_size + ZO__data # VirtualAddress
+ .long ZO__edata - ZO__data # SizeOfRawData
+ .long setup_size + ZO__data # PointerToRawData
+
+ .long 0, 0, 0
+ .long IMAGE_SCN_CNT_INITIALIZED_DATA | \
+ IMAGE_SCN_MEM_READ | \
+ IMAGE_SCN_MEM_WRITE # Characteristics
+
.set section_count, (. - section_table) / 40
#endif /* CONFIG_EFI_STUB */