[PATCH 1/4] modpost: change return type of addend_*_rel()

[PATCH 1/4] modpost: change return type of addend_*_rel()

[Masahiro Yamada]

Now that none of addend_*_rel() returns a meaningful value (the return
value is always 0), change all of them to return the value of r_addend.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 scripts/mod/modpost.c | 63 +++++++++++++++++--------------------------
 1 file changed, 24 insertions(+), 39 deletions(-)

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 8227641dd087..a8e85b7cc0da 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -1257,21 +1257,18 @@ static void check_section_mismatch(struct module *mod, struct elf_info *elf,
 				 tosec, taddr);
 }
 
-static int addend_386_rel(uint32_t *location, Elf_Rela *r)
+static Elf_Addr addend_386_rel(uint32_t *location, Elf_Rela *r)
 {
 	unsigned int r_typ = ELF_R_TYPE(r->r_info);
 
 	switch (r_typ) {
 	case R_386_32:
-		r->r_addend = TO_NATIVE(*location);
-		break;
+		return TO_NATIVE(*location);
 	case R_386_PC32:
-		r->r_addend = TO_NATIVE(*location) + 4;
-		break;
-	default:
-		r->r_addend = (Elf_Addr)(-1);
+		return TO_NATIVE(*location) + 4;
 	}
-	return 0;
+
+	return (Elf_Addr)(-1);
 }
 
 #ifndef R_ARM_CALL
@@ -1315,7 +1312,7 @@ static int32_t sign_extend32(int32_t value, int index)
 	return (int32_t)(value << shift) >> shift;
 }
 
-static int addend_arm_rel(void *loc, Elf_Sym *sym, Elf_Rela *r)
+static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, Elf_Rela *r)
 {
 	unsigned int r_typ = ELF_R_TYPE(r->r_info);
 	uint32_t inst, upper, lower, sign, j1, j2;
@@ -1325,22 +1322,19 @@ static int addend_arm_rel(void *loc, Elf_Sym *sym, Elf_Rela *r)
 	case R_ARM_ABS32:
 	case R_ARM_REL32:
 		inst = TO_NATIVE(*(uint32_t *)loc);
-		r->r_addend = inst + sym->st_value;
-		break;
+		return inst + sym->st_value;
 	case R_ARM_MOVW_ABS_NC:
 	case R_ARM_MOVT_ABS:
 		inst = TO_NATIVE(*(uint32_t *)loc);
 		offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff),
 				       15);
-		r->r_addend = offset + sym->st_value;
-		break;
+		return offset + sym->st_value;
 	case R_ARM_PC24:
 	case R_ARM_CALL:
 	case R_ARM_JUMP24:
 		inst = TO_NATIVE(*(uint32_t *)loc);
 		offset = sign_extend32((inst & 0x00ffffff) << 2, 25);
-		r->r_addend = offset + sym->st_value + 8;
-		break;
+		return offset + sym->st_value + 8;
 	case R_ARM_THM_MOVW_ABS_NC:
 	case R_ARM_THM_MOVT_ABS:
 		upper = TO_NATIVE(*(uint16_t *)loc);
@@ -1350,8 +1344,7 @@ static int addend_arm_rel(void *loc, Elf_Sym *sym, Elf_Rela *r)
 				       ((lower & 0x7000) >> 4) |
 				       (lower & 0x00ff),
 				       15);
-		r->r_addend = offset + sym->st_value;
-		break;
+		return offset + sym->st_value;
 	case R_ARM_THM_JUMP19:
 		/*
 		 * Encoding T3:
@@ -1372,8 +1365,7 @@ static int addend_arm_rel(void *loc, Elf_Sym *sym, Elf_Rela *r)
 				       ((upper & 0x03f) << 12) |
 				       ((lower & 0x07ff) << 1),
 				       20);
-		r->r_addend = offset + sym->st_value + 4;
-		break;
+		return offset + sym->st_value + 4;
 	case R_ARM_THM_CALL:
 	case R_ARM_THM_JUMP24:
 		/*
@@ -1399,15 +1391,13 @@ static int addend_arm_rel(void *loc, Elf_Sym *sym, Elf_Rela *r)
 				       ((upper & 0x03ff) << 12) |
 				       ((lower & 0x07ff) << 1),
 				       24);
-		r->r_addend = offset + sym->st_value + 4;
-		break;
-	default:
-		r->r_addend = (Elf_Addr)(-1);
+		return offset + sym->st_value + 4;
 	}
-	return 0;
+
+	return (Elf_Addr)(-1);
 }
 
-static int addend_mips_rel(uint32_t *location, Elf_Rela *r)
+static Elf_Addr addend_mips_rel(uint32_t *location, Elf_Rela *r)
 {
 	unsigned int r_typ = ELF_R_TYPE(r->r_info);
 	uint32_t inst;
@@ -1415,18 +1405,13 @@ static int addend_mips_rel(uint32_t *location, Elf_Rela *r)
 	inst = TO_NATIVE(*location);
 	switch (r_typ) {
 	case R_MIPS_LO16:
-		r->r_addend = inst & 0xffff;
-		break;
+		return inst & 0xffff;
 	case R_MIPS_26:
-		r->r_addend = (inst & 0x03ffffff) << 2;
-		break;
+		return (inst & 0x03ffffff) << 2;
 	case R_MIPS_32:
-		r->r_addend = inst;
-		break;
-	default:
-		r->r_addend = (Elf_Addr)(-1);
+		return inst;
 	}
-	return 0;
+	return (Elf_Addr)(-1);
 }
 
 #ifndef EM_RISCV
@@ -1513,6 +1498,7 @@ static void section_rel(struct module *mod, struct elf_info *elf,
 
 	for (rel = start; rel < stop; rel++) {
 		Elf_Sym *tsym;
+		Elf_Addr taddr = 0;
 		void *loc;
 
 		r.r_offset = TO_NATIVE(rel->r_offset);
@@ -1531,27 +1517,26 @@ static void section_rel(struct module *mod, struct elf_info *elf,
 		r.r_info = TO_NATIVE(rel->r_info);
 		r_sym = ELF_R_SYM(r.r_info);
 #endif
-		r.r_addend = 0;
 
 		loc = sym_get_data_by_offset(elf, fsecndx, r.r_offset);
 		tsym = elf->symtab_start + r_sym;
 
 		switch (elf->hdr->e_machine) {
 		case EM_386:
-			addend_386_rel(loc, &r);
+			taddr = addend_386_rel(loc, &r);
 			break;
 		case EM_ARM:
-			addend_arm_rel(loc, tsym, &r);
+			taddr = addend_arm_rel(loc, tsym, &r);
 			break;
 		case EM_MIPS:
-			addend_mips_rel(loc, &r);
+			taddr = addend_mips_rel(loc, &r);
 			break;
 		default:
 			fatal("Please add code to calculate addend for this architecture\n");
 		}
 
 		check_section_mismatch(mod, elf, tsym,
-				       fsecndx, fromsec, r.r_offset, r.r_addend);
+				       fsecndx, fromsec, r.r_offset, taddr);
 	}
 }
 
-- 
2.39.2

[PATCH 2/4] modpost: pass r_type to addend_*_rel()

[Masahiro Yamada]

All of addend_*_rel() need the Elf_Rela pointer just for calculating
ELF_R_TYPE(r->r_info).

You can do it on the caller to de-duplicate the code.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 scripts/mod/modpost.c | 24 +++++++++++-------------
 1 file changed, 11 insertions(+), 13 deletions(-)

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index a8e85b7cc0da..570a6cb6dd00 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -1257,11 +1257,9 @@ static void check_section_mismatch(struct module *mod, struct elf_info *elf,
 				 tosec, taddr);
 }
 
-static Elf_Addr addend_386_rel(uint32_t *location, Elf_Rela *r)
+static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type)
 {
-	unsigned int r_typ = ELF_R_TYPE(r->r_info);
-
-	switch (r_typ) {
+	switch (r_type) {
 	case R_386_32:
 		return TO_NATIVE(*location);
 	case R_386_PC32:
@@ -1312,13 +1310,12 @@ static int32_t sign_extend32(int32_t value, int index)
 	return (int32_t)(value << shift) >> shift;
 }
 
-static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, Elf_Rela *r)
+static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type)
 {
-	unsigned int r_typ = ELF_R_TYPE(r->r_info);
 	uint32_t inst, upper, lower, sign, j1, j2;
 	int32_t offset;
 
-	switch (r_typ) {
+	switch (r_type) {
 	case R_ARM_ABS32:
 	case R_ARM_REL32:
 		inst = TO_NATIVE(*(uint32_t *)loc);
@@ -1397,13 +1394,12 @@ static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, Elf_Rela *r)
 	return (Elf_Addr)(-1);
 }
 
-static Elf_Addr addend_mips_rel(uint32_t *location, Elf_Rela *r)
+static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type)
 {
-	unsigned int r_typ = ELF_R_TYPE(r->r_info);
 	uint32_t inst;
 
 	inst = TO_NATIVE(*location);
-	switch (r_typ) {
+	switch (r_type) {
 	case R_MIPS_LO16:
 		return inst & 0xffff;
 	case R_MIPS_26:
@@ -1500,6 +1496,7 @@ static void section_rel(struct module *mod, struct elf_info *elf,
 		Elf_Sym *tsym;
 		Elf_Addr taddr = 0;
 		void *loc;
+		unsigned int r_type;
 
 		r.r_offset = TO_NATIVE(rel->r_offset);
 #if KERNEL_ELFCLASS == ELFCLASS64
@@ -1520,16 +1517,17 @@ static void section_rel(struct module *mod, struct elf_info *elf,
 
 		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:
-			taddr = addend_386_rel(loc, &r);
+			taddr = addend_386_rel(loc, r_type);
 			break;
 		case EM_ARM:
-			taddr = addend_arm_rel(loc, tsym, &r);
+			taddr = addend_arm_rel(loc, tsym, r_type);
 			break;
 		case EM_MIPS:
-			taddr = addend_mips_rel(loc, &r);
+			taddr = addend_mips_rel(loc, r_type);
 			break;
 		default:
 			fatal("Please add code to calculate addend for this architecture\n");
-- 
2.39.2

[PATCH 3/4] modpost: clean up MIPS64 little endian relocation code

[Masahiro Yamada]

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@kernel.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

[PATCH 4/4] modpost: remove ElF_Rela variables from for-loop in section_rel(a)

[Masahiro Yamada]

Remove the Elf_Rela variables used in the for-loop in section_rel().

This makes the code consistent; section_rel() only uses Elf_Rel,
section_rela() only uses Elf_Rela.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 scripts/mod/modpost.c | 25 +++++++++++--------------
 1 file changed, 11 insertions(+), 14 deletions(-)

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index ca04b87c1679..9761f9d0eec0 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -1465,8 +1465,6 @@ static void section_rela(struct module *mod, struct elf_info *elf,
 			 Elf_Shdr *sechdr)
 {
 	Elf_Rela *rela;
-	Elf_Rela r;
-	unsigned int r_sym;
 	unsigned int fsecndx = sechdr->sh_info;
 	const char *fromsec = sec_name(elf, fsecndx);
 	Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
@@ -1477,12 +1475,14 @@ static void section_rela(struct module *mod, struct elf_info *elf,
 		return;
 
 	for (rela = start; rela < stop; rela++) {
-		unsigned int r_type;
+		Elf_Addr taddr, r_offset;
+		unsigned int r_type, r_sym;
 
-		r.r_offset = TO_NATIVE(rela->r_offset);
+		r_offset = TO_NATIVE(rela->r_offset);
 		get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym);
 
-		r.r_addend = TO_NATIVE(rela->r_addend);
+		taddr = TO_NATIVE(rela->r_addend);
+
 		switch (elf->hdr->e_machine) {
 		case EM_RISCV:
 			if (!strcmp("__ex_table", fromsec) &&
@@ -1497,7 +1497,7 @@ static void section_rela(struct module *mod, struct elf_info *elf,
 		}
 
 		check_section_mismatch(mod, elf, elf->symtab_start + r_sym,
-				       fsecndx, fromsec, r.r_offset, r.r_addend);
+				       fsecndx, fromsec, r_offset, taddr);
 	}
 }
 
@@ -1505,8 +1505,6 @@ static void section_rel(struct module *mod, struct elf_info *elf,
 			Elf_Shdr *sechdr)
 {
 	Elf_Rel *rel;
-	Elf_Rela r;
-	unsigned int r_sym;
 	unsigned int fsecndx = sechdr->sh_info;
 	const char *fromsec = sec_name(elf, fsecndx);
 	Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
@@ -1518,15 +1516,14 @@ static void section_rel(struct module *mod, struct elf_info *elf,
 
 	for (rel = start; rel < stop; rel++) {
 		Elf_Sym *tsym;
-		Elf_Addr taddr = 0;
+		Elf_Addr taddr = 0, r_offset;
+		unsigned int r_type, r_sym;
 		void *loc;
-		unsigned int r_type;
-
-		r.r_offset = TO_NATIVE(rel->r_offset);
 
+		r_offset = TO_NATIVE(rel->r_offset);
 		get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym);
 
-		loc = sym_get_data_by_offset(elf, fsecndx, r.r_offset);
+		loc = sym_get_data_by_offset(elf, fsecndx, r_offset);
 		tsym = elf->symtab_start + r_sym;
 
 		switch (elf->hdr->e_machine) {
@@ -1544,7 +1541,7 @@ static void section_rel(struct module *mod, struct elf_info *elf,
 		}
 
 		check_section_mismatch(mod, elf, tsym,
-				       fsecndx, fromsec, r.r_offset, taddr);
+				       fsecndx, fromsec, r_offset, taddr);
 	}
 }
 
-- 
2.39.2