[PATCH] riscv: hwprobe: do not produce frtace relocation
From: Vladimir Isaev
Date: Wed Mar 13 2024 - 05:07:46 EST
Such relocation causes crash of android linker similar to one
described in commit e05d57dcb8c7
("riscv: Fixup __vdso_gettimeofday broke dynamic ftrace").
Looks like this relocation is added by CONFIG_DYNAMIC_FTRACE which is
disabled in the default android kernel.
Before:
readelf -rW arch/riscv/kernel/vdso/vdso.so:
Relocation section '.rela.dyn' at offset 0xd00 contains 1 entry:
Offset Info Type
0000000000000d20 0000000000000003 R_RISCV_RELATIVE
objdump:
0000000000000c86 <__vdso_riscv_hwprobe@@LINUX_4.15>:
c86: 0001 nop
c88: 0001 nop
c8a: 0001 nop
c8c: 0001 nop
c8e: e211 bnez a2,c92 <__vdso_riscv_hwprobe...
After:
readelf -rW arch/riscv/kernel/vdso/vdso.so:
There are no relocations in this file.
objdump:
0000000000000c86 <__vdso_riscv_hwprobe@@LINUX_4.15>:
c86: e211 bnez a2,c8a <__vdso_riscv_hwprobe...
c88: c6b9 beqz a3,cd6 <__vdso_riscv_hwprobe...
c8a: e739 bnez a4,cd8 <__vdso_riscv_hwprobe...
c8c: ffffd797 auipc a5,0xffffd
Also disable SCS since it also should not be available in vdso.
Fixes: aa5af0aa90ba ("RISC-V: Add hwprobe vDSO function and data")
Signed-off-by: Roman Artemev <roman.artemev@xxxxxxxxxxxxx>
Signed-off-by: Vladimir Isaev <vladimir.isaev@xxxxxxxxxxxxx>
---
arch/riscv/kernel/vdso/Makefile | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile
index 9b517fe1b8a8..272c431ac5b9 100644
--- a/arch/riscv/kernel/vdso/Makefile
+++ b/arch/riscv/kernel/vdso/Makefile
@@ -37,6 +37,7 @@ endif
# Disable -pg to prevent insert call site
CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS)
+CFLAGS_REMOVE_hwprobe.o = $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS)
# Disable profiling and instrumentation for VDSO code
GCOV_PROFILE := n
--
2.43.0