diff mbox series

Makefile: apply dynamic relocations for LLD

Message ID 20220926204740.861969-1-adelva@google.com
State Accepted
Delegated to: Tom Rini
Headers show
Series Makefile: apply dynamic relocations for LLD | expand

Commit Message

Alistair Delva Sept. 26, 2022, 8:47 p.m. UTC 
From: Nick Desaulniers <ndesaulniers@google.com>

It seems that for aarch64, unless we apply dynamic relocations to the
location being relocated, we fail to boot.

As Fangrui notes:
  For dynamic relocations using the RELA format (readelf -Wr), GNU ld
  sets the initial content to r_addend; ld.lld doesn't do that by
  default (needs --apply-dynamic-relocs).

Otherwise .rodata appears to be full of NUL-bytes before relocation,
causing crashes when trying to invoke the function pointers in
init_sequence_f from initcall_run_list().

Link: https://reviews.llvm.org/D42797
Suggested-by: Fangrui Song <maskray@google.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Alistair Delva <adelva@google.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Tom Rini <trini@konsulko.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
---
 Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Tom Rini Oct. 11, 2022, 1:56 p.m. UTC | #1 
On Mon, Sep 26, 2022 at 08:47:40PM +0000, Alistair Delva wrote:

> From: Nick Desaulniers <ndesaulniers@google.com>
> 
> It seems that for aarch64, unless we apply dynamic relocations to the
> location being relocated, we fail to boot.
> 
> As Fangrui notes:
>   For dynamic relocations using the RELA format (readelf -Wr), GNU ld
>   sets the initial content to r_addend; ld.lld doesn't do that by
>   default (needs --apply-dynamic-relocs).
> 
> Otherwise .rodata appears to be full of NUL-bytes before relocation,
> causing crashes when trying to invoke the function pointers in
> init_sequence_f from initcall_run_list().
> 
> Link: https://reviews.llvm.org/D42797
> Suggested-by: Fangrui Song <maskray@google.com>
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
> Signed-off-by: Alistair Delva <adelva@google.com>
> Cc: Simon Glass <sjg@chromium.org>
> Cc: Tom Rini <trini@konsulko.com>
> Cc: Nick Desaulniers <ndesaulniers@google.com>

Applied to u-boot/master, thanks!
diff mbox series

Patch

diff --git a/Makefile b/Makefile
index 010ace9d7c..af06b7aa19 100644
--- a/Makefile
+++ b/Makefile
@@ -1022,7 +1022,7 @@  LDFLAGS_u-boot += $(LDFLAGS_FINAL)
 LDFLAGS_u-boot += $(call ld-option, --no-dynamic-linker)
 
 # ld.lld support
-LDFLAGS_u-boot += -z notext
+LDFLAGS_u-boot += -z notext $(call ld-option,--apply-dynamic-relocs)
 
 LDFLAGS_u-boot += --build-id=none