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objtool: Handle various symbol types of rodata

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In the relocation section ".rela.rodata" of each .o file compiled with
LoongArch toolchain, there are various symbol types such as STT_NOTYPE,
STT_OBJECT, STT_FUNC in addition to the usual STT_SECTION, it needs to
use reloc symbol offset instead of reloc addend to find the destination
instruction in find_jump_table() and add_jump_table().

For the most part, an absolute relocation type is used for rodata. In the
case of STT_SECTION, reloc->sym->offset is always zero, and for the other
symbol types, reloc_addend(reloc) is always zero, thus it can use a simple
statement "reloc->sym->offset + reloc_addend(reloc)" to obtain the symbol
offset for various symbol types.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Link: https://lore.kernel.org/r/20250211115016.26913-2-yangtiezhu@loongson.cn
Acked-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
This commit is contained in:
Tiezhu Yang 2025-02-11 19:50:10 +08:00 committed by Josh Poimboeuf
parent bf71940fc1
commit ab6ce22b78
1 changed files with 11 additions and 5 deletions
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16
tools/objtool/check.c
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@ -1954,6 +1954,7 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn,
unsigned int prev_offset = 0;
struct reloc *reloc = table;
struct alternative *alt;
unsigned long sym_offset;
/*
* Each @reloc is a switch table relocation which points to the target
@ -1971,9 +1972,10 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn,
if (prev_offset && reloc_offset(reloc) != prev_offset + 8)
break;
sym_offset = reloc->sym->offset + reloc_addend(reloc);
/* Detect function pointers from contiguous objects: */
if (reloc->sym->sec == pfunc->sec &&
reloc_addend(reloc) == pfunc->offset)
if (reloc->sym->sec == pfunc->sec && sym_offset == pfunc->offset)
break;
/*
@ -1981,10 +1983,10 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn,
* which point to the end of the function. Ignore them.
*/
if (reloc->sym->sec == pfunc->sec &&
reloc_addend(reloc) == pfunc->offset + pfunc->len)
sym_offset == pfunc->offset + pfunc->len)
goto next;
dest_insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
dest_insn = find_insn(file, reloc->sym->sec, sym_offset);
if (!dest_insn)
break;
@ -2023,6 +2025,7 @@ static void find_jump_table(struct objtool_file *file, struct symbol *func,
struct reloc *table_reloc;
struct instruction *dest_insn, *orig_insn = insn;
unsigned long table_size;
unsigned long sym_offset;
/*
* Backward search using the @first_jump_src links, these help avoid
@ -2046,7 +2049,10 @@ static void find_jump_table(struct objtool_file *file, struct symbol *func,
table_reloc = arch_find_switch_table(file, insn, &table_size);
if (!table_reloc)
continue;
dest_insn = find_insn(file, table_reloc->sym->sec, reloc_addend(table_reloc));
sym_offset = table_reloc->sym->offset + reloc_addend(table_reloc);
dest_insn = find_insn(file, table_reloc->sym->sec, sym_offset);
if (!dest_insn || !insn_func(dest_insn) || insn_func(dest_insn)->pfunc != func)
continue;