objtool: Handle various symbol types of rodata

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>

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index ce973d9d8e6d816d726150cda6aaa5fea9fababf..cfab4a1b1f706b7412aa8b3202a163cd84b0f6af 100644 (file)
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -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;