[U-Boot] [PATCH] efi_loader: Handle RELA absolute relocations properly

With RELA absolute relocations, the relocation target contains our link offset which we need to remove from the equation again. We did this properly in the relative relocation path, but not in the absolute one.
So let's do this for the absolute one as well. That way, u-boot can have a TEXT_OFFSET of != 0 and still relocate itself properly.
This fixes a bug where efi_loader did not work on the RISC-V QEMU port. With this patch, I can successfully run UEFI applications on the RISC-V QEMU port.
Reported-by: Auer, Lukas lukas.auer@aisec.fraunhofer.de Signed-off-by: Alexander Graf agraf@suse.de --- lib/efi_loader/efi_runtime.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/lib/efi_loader/efi_runtime.c b/lib/efi_loader/efi_runtime.c index abcf03c5a4..ca66d33e58 100644 --- a/lib/efi_loader/efi_runtime.c +++ b/lib/efi_loader/efi_runtime.c @@ -380,6 +380,9 @@ void efi_runtime_relocate(ulong offset, struct efi_mem_desc *map) ulong symidx = rel->info >> SYM_INDEX; extern struct dyn_sym __dyn_sym_start[]; newaddr = __dyn_sym_start[symidx].addr + offset; +#ifdef IS_RELA + newaddr -= CONFIG_SYS_TEXT_BASE; +#endif break; } #endif

On Mon, Nov 5, 2018 at 5:28 AM Alexander Graf agraf@suse.de wrote:
With RELA absolute relocations, the relocation target contains our link offset which we need to remove from the equation again. We did this properly in the relative relocation path, but not in the absolute one.
So let's do this for the absolute one as well. That way, u-boot can have a TEXT_OFFSET of != 0 and still relocate itself properly.
This fixes a bug where efi_loader did not work on the RISC-V QEMU port. With this patch, I can successfully run UEFI applications on the RISC-V QEMU port.
Reported-by: Auer, Lukas lukas.auer@aisec.fraunhofer.de Signed-off-by: Alexander Graf agraf@suse.de
lib/efi_loader/efi_runtime.c | 3 +++ 1 file changed, 3 insertions(+)
Tested-by: Bin Meng bmeng.cn@gmail.com

On Sun, 2018-11-04 at 22:28 +0100, Alexander Graf wrote:
With RELA absolute relocations, the relocation target contains our link offset which we need to remove from the equation again. We did this properly in the relative relocation path, but not in the absolute one.
So let's do this for the absolute one as well. That way, u-boot can have a TEXT_OFFSET of != 0 and still relocate itself properly.
This fixes a bug where efi_loader did not work on the RISC-V QEMU port. With this patch, I can successfully run UEFI applications on the RISC-V QEMU port.
Reported-by: Auer, Lukas lukas.auer@aisec.fraunhofer.de Signed-off-by: Alexander Graf agraf@suse.de
lib/efi_loader/efi_runtime.c | 3 +++ 1 file changed, 3 insertions(+)
Tested-by: Lukas Auer lukas.auer@aisec.fraunhofer.de
Thanks for the patch! That explains why it was working on the Andes targets.
Lukas
participants (3)
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Alexander Graf
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Auer, Lukas
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Bin Meng