Re: [PATCH v3 03/10] objtool: Handle different entry size of rodata

From: Jinyang He
Date: Tue Nov 19 2024 - 05:47:57 EST



On 2024-11-19 14:56, Tiezhu Yang wrote:
In the most cases, the entry size of rodata is 8 bytes because the
relocation type is 64 bit, but when compling with Clang on LoongArch,
there exists 32 bit relocation type, the entry size of rodata should
be 4 bytes in this case.

This is preparation for later patch on LoongArch, there is no effect
for the other archs with this patch.

Signed-off-by: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
---
tools/objtool/check.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 6607cd56459b..af824bfd0973 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -2092,6 +2092,7 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn,
struct reloc *reloc = table;
struct alternative *alt;
unsigned long offset;
+ unsigned long rodata_entry_size;
/*
* Each @reloc is a switch table relocation which points to the target
@@ -2103,8 +2104,15 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn,
if (reloc != table && reloc == next_table)
break;
+ /* Handle the special cases compiled with Clang on LoongArch */
+ if (file->elf->ehdr.e_machine == EM_LOONGARCH &&
+ reloc_type(reloc) == R_LARCH_32_PCREL)
It is arch-specific. I'd prefer to rewrite an interface in arch directory
to get the entry size in rodata by arch different relocation types.
And I think this patch should merge to other patches e.g. [07/10].
+ rodata_entry_size = 4;
+ else
+ rodata_entry_size = 8;
+
/* Make sure the table entries are consecutive: */
- if (prev_offset && reloc_offset(reloc) != prev_offset + 8)
+ if (prev_offset && reloc_offset(reloc) != prev_offset + rodata_entry_size)
break;
if (reloc->sym->type == STT_SECTION) {