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| author | Masahiro Yamada <yamada.masahiro@socionext.com> | 2020-01-17 13:44:50 +0900 |
|---|---|---|
| committer | Masahiro Yamada <yamada.masahiro@socionext.com> | 2020-01-24 22:34:25 +0900 |
| commit | 511046eaa28f89d0ae1d8577bc940ad02d129f19 (patch) | |
| tree | fb42946474828ed4e9102d050aa633b94912bcb5 | |
| parent | 320920c15f7b828e34f874c4afb8fa78a3dccb71 (diff) | |
| download | platform_external_arm-trusted-firmware-511046eaa28f89d0ae1d8577bc940ad02d129f19.tar.gz platform_external_arm-trusted-firmware-511046eaa28f89d0ae1d8577bc940ad02d129f19.tar.bz2 platform_external_arm-trusted-firmware-511046eaa28f89d0ae1d8577bc940ad02d129f19.zip | |
BL31: discard .dynsym .dynstr .hash sections to make ENABLE_PIE work
When I tried ENABLE_PIE for my PLAT=uniphier platform, BL31 crashed
at its entry. When it is built with ENABLE_PIE=1, some sections are
inserted before the executable code.
$ make PLAT=uniphier CROSS_COMPILE=aarch64-linux-gnu- ENABLE_PIE=1 bl31
$ aarch64-linux-gnu-objdump -h build/uniphier/release/bl31/bl31.elf | head -n 13
build/uniphier/release/bl31/bl31.elf: file format elf64-littleaarch64
Sections:
Idx Name Size VMA LMA File off Algn
0 .dynsym 000002a0 0000000081000000 0000000081000000 00010000 2**3
CONTENTS, ALLOC, LOAD, READONLY, DATA
1 .dynstr 000002a0 00000000810002a0 00000000810002a0 000102a0 2**0
CONTENTS, ALLOC, LOAD, READONLY, DATA
2 .hash 00000124 0000000081000540 0000000081000540 00010540 2**3
CONTENTS, ALLOC, LOAD, READONLY, DATA
3 ro 0000699c 0000000081000664 0000000081000664 00010664 2**11
CONTENTS, ALLOC, LOAD, CODE
The previous stage loader generally jumps over to the base address of
BL31, where no valid instruction exists.
I checked the linker script of Linux (arch/arm64/kernel/vmlinux.lds.S)
and U-Boot (arch/arm/cpu/armv8/u-boot.lds), both of which support
relocation. They simply discard those sections.
Do similar in TF-A too.
Change-Id: I6c33e9143856765d4ffa24f3924b0ab51a17cde9
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| -rw-r--r-- | bl31/bl31.ld.S | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/bl31/bl31.ld.S b/bl31/bl31.ld.S index 42227f0f3..c7185a893 100644 --- a/bl31/bl31.ld.S +++ b/bl31/bl31.ld.S @@ -339,6 +339,10 @@ SECTIONS __RW_END__ = .; __BL31_END__ = .; + /DISCARD/ : { + *(.dynsym .dynstr .hash .gnu.hash) + } + ASSERT(. <= BL31_LIMIT, "BL31 image has exceeded its limit.") #endif } |