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Message-Id: <20230723100446.3062358-3-masahiroy@kernel.org>
Date: Sun, 23 Jul 2023 19:04:45 +0900
From: Masahiro Yamada <masahiroy@...nel.org>
To: linux-kbuild@...r.kernel.org
Cc: linux-kernel@...r.kernel.org,
Masahiro Yamada <masahiroy@...nel.org>,
Nathan Chancellor <nathan@...nel.org>,
Nick Desaulniers <ndesaulniers@...gle.com>,
Nicolas Schier <nicolas@...sle.eu>
Subject: [PATCH 3/4] modpost: clean up MIPS64 little endian relocation code
MIPS64 little endian target has an odd encoding of r_info.
This commit makes the special handling less ugly. It is still ugly,
but #if conditionals will go away, at least.
Signed-off-by: Masahiro Yamada <masahiroy@...nel.org>
---
scripts/mod/modpost.c | 76 ++++++++++++++++++++++++-------------------
scripts/mod/modpost.h | 22 -------------
2 files changed, 43 insertions(+), 55 deletions(-)
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 570a6cb6dd00..ca04b87c1679 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -1426,6 +1426,41 @@ static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type)
#define R_LARCH_SUB32 55
#endif
+static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info,
+ unsigned int *r_type, unsigned int *r_sym)
+{
+ typedef struct {
+ Elf64_Word r_sym; /* Symbol index */
+ unsigned char r_ssym; /* Special symbol for 2nd relocation */
+ unsigned char r_type3; /* 3rd relocation type */
+ unsigned char r_type2; /* 2nd relocation type */
+ unsigned char r_type; /* 1st relocation type */
+ } Elf64_Mips_R_Info;
+
+ bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64);
+
+ if (elf->hdr->e_machine == EM_MIPS && is_64bit) {
+ Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info;
+
+ *r_type = mips64_r_info->r_type;
+ *r_sym = TO_NATIVE(mips64_r_info->r_sym);
+ return;
+ }
+
+ if (is_64bit) {
+ Elf64_Xword r_info64 = r_info;
+
+ r_info = TO_NATIVE(r_info64);
+ } else {
+ Elf32_Word r_info32 = r_info;
+
+ r_info = TO_NATIVE(r_info32);
+ }
+
+ *r_type = ELF_R_TYPE(r_info);
+ *r_sym = ELF_R_SYM(r_info);
+}
+
static void section_rela(struct module *mod, struct elf_info *elf,
Elf_Shdr *sechdr)
{
@@ -1442,32 +1477,21 @@ static void section_rela(struct module *mod, struct elf_info *elf,
return;
for (rela = start; rela < stop; rela++) {
+ unsigned int r_type;
+
r.r_offset = TO_NATIVE(rela->r_offset);
-#if KERNEL_ELFCLASS == ELFCLASS64
- if (elf->hdr->e_machine == EM_MIPS) {
- unsigned int r_typ;
- r_sym = ELF64_MIPS_R_SYM(rela->r_info);
- r_sym = TO_NATIVE(r_sym);
- r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
- r.r_info = ELF64_R_INFO(r_sym, r_typ);
- } else {
- r.r_info = TO_NATIVE(rela->r_info);
- r_sym = ELF_R_SYM(r.r_info);
- }
-#else
- r.r_info = TO_NATIVE(rela->r_info);
- r_sym = ELF_R_SYM(r.r_info);
-#endif
+ get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym);
+
r.r_addend = TO_NATIVE(rela->r_addend);
switch (elf->hdr->e_machine) {
case EM_RISCV:
if (!strcmp("__ex_table", fromsec) &&
- ELF_R_TYPE(r.r_info) == R_RISCV_SUB32)
+ r_type == R_RISCV_SUB32)
continue;
break;
case EM_LOONGARCH:
if (!strcmp("__ex_table", fromsec) &&
- ELF_R_TYPE(r.r_info) == R_LARCH_SUB32)
+ r_type == R_LARCH_SUB32)
continue;
break;
}
@@ -1499,25 +1523,11 @@ static void section_rel(struct module *mod, struct elf_info *elf,
unsigned int r_type;
r.r_offset = TO_NATIVE(rel->r_offset);
-#if KERNEL_ELFCLASS == ELFCLASS64
- if (elf->hdr->e_machine == EM_MIPS) {
- unsigned int r_typ;
- r_sym = ELF64_MIPS_R_SYM(rel->r_info);
- r_sym = TO_NATIVE(r_sym);
- r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
- r.r_info = ELF64_R_INFO(r_sym, r_typ);
- } else {
- r.r_info = TO_NATIVE(rel->r_info);
- r_sym = ELF_R_SYM(r.r_info);
- }
-#else
- r.r_info = TO_NATIVE(rel->r_info);
- r_sym = ELF_R_SYM(r.r_info);
-#endif
+
+ get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym);
loc = sym_get_data_by_offset(elf, fsecndx, r.r_offset);
tsym = elf->symtab_start + r_sym;
- r_type = ELF_R_TYPE(r.r_info);
switch (elf->hdr->e_machine) {
case EM_386:
diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h
index dfdb9484e325..5f94c2c9f2d9 100644
--- a/scripts/mod/modpost.h
+++ b/scripts/mod/modpost.h
@@ -50,28 +50,6 @@
#define ELF_R_TYPE ELF64_R_TYPE
#endif
-/* The 64-bit MIPS ELF ABI uses an unusual reloc format. */
-typedef struct
-{
- Elf32_Word r_sym; /* Symbol index */
- unsigned char r_ssym; /* Special symbol for 2nd relocation */
- unsigned char r_type3; /* 3rd relocation type */
- unsigned char r_type2; /* 2nd relocation type */
- unsigned char r_type1; /* 1st relocation type */
-} _Elf64_Mips_R_Info;
-
-typedef union
-{
- Elf64_Xword r_info_number;
- _Elf64_Mips_R_Info r_info_fields;
-} _Elf64_Mips_R_Info_union;
-
-#define ELF64_MIPS_R_SYM(i) \
- ((__extension__ (_Elf64_Mips_R_Info_union)(i)).r_info_fields.r_sym)
-
-#define ELF64_MIPS_R_TYPE(i) \
- ((__extension__ (_Elf64_Mips_R_Info_union)(i)).r_info_fields.r_type1)
-
#if KERNEL_ELFDATA != HOST_ELFDATA
static inline void __endian(const void *src, void *dest, unsigned int size)
--
2.39.2
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