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

Alexander Graf agraf at suse.de
Sun Nov 4 21:28:55 UTC 2018


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 at aisec.fraunhofer.de>
Signed-off-by: Alexander Graf <agraf at 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
-- 
2.12.3



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