scripts/sorttable: Use a structure of function pointers for elf helpers

Commit Message

Steven Rostedt Jan. 10, 2025, 12:54 p.m. UTC

From: Steven Rostedt <[e-mail]>

Instead of having a series of function pointers that gets assigned to the
Elf64 or Elf32 versions, put them all into a single structure and use
that. Add the helper function that chooses the structure into the macros
that build the different versions of the elf functions.

Link: https://lore.kernel.org/all/CAHk-=[e-mail]/

Suggested-by: Linus Torvalds <[e-mail]>
Signed-off-by: Steven Rostedt (Google) <[e-mail]>
---
 scripts/sorttable.c | 175 +++++++++++++++++++++++++++++---------------
 1 file changed, 118 insertions(+), 57 deletions(-)

Patch

diff --git a/scripts/sorttable.c b/scripts/sorttable.c
index 656c1e9b5ad9..9f41575afd7a 100644
--- a/scripts/sorttable.c
+++ b/scripts/sorttable.c
@@ -85,6 +85,25 @@  static uint64_t (*r8)(const uint64_t *);
 static void (*w)(uint32_t, uint32_t *);
 typedef void (*table_sort_t)(char *, int);
 
+static struct elf_funcs {
+	int (*compare_extable)(const void *a, const void *b);
+	uint64_t (*ehdr_shoff)(Elf_Ehdr *ehdr);
+	uint16_t (*ehdr_shstrndx)(Elf_Ehdr *ehdr);
+	uint16_t (*ehdr_shentsize)(Elf_Ehdr *ehdr);
+	uint16_t (*ehdr_shnum)(Elf_Ehdr *ehdr);
+	uint64_t (*shdr_addr)(Elf_Shdr *shdr);
+	uint64_t (*shdr_offset)(Elf_Shdr *shdr);
+	uint64_t (*shdr_size)(Elf_Shdr *shdr);
+	uint64_t (*shdr_entsize)(Elf_Shdr *shdr);
+	uint32_t (*shdr_link)(Elf_Shdr *shdr);
+	uint32_t (*shdr_name)(Elf_Shdr *shdr);
+	uint32_t (*shdr_type)(Elf_Shdr *shdr);
+	uint8_t (*sym_type)(Elf_Sym *sym);
+	uint32_t (*sym_name)(Elf_Sym *sym);
+	uint64_t (*sym_value)(Elf_Sym *sym);
+	uint16_t (*sym_shndx)(Elf_Sym *sym);
+} e;
+
 static uint64_t ehdr64_shoff(Elf_Ehdr *ehdr)
 {
 	return r8(&ehdr->e64.e_shoff);
@@ -95,6 +114,11 @@  static uint64_t ehdr32_shoff(Elf_Ehdr *ehdr)
 	return r(&ehdr->e32.e_shoff);
 }
 
+static uint64_t ehdr_shoff(Elf_Ehdr *ehdr)
+{
+	return e.ehdr_shoff(ehdr);
+}
+
 #define EHDR_HALF(fn_name)				\
 static uint16_t ehdr64_##fn_name(Elf_Ehdr *ehdr)	\
 {							\
@@ -104,6 +128,11 @@  static uint16_t ehdr64_##fn_name(Elf_Ehdr *ehdr)	\
 static uint16_t ehdr32_##fn_name(Elf_Ehdr *ehdr)	\
 {							\
 	return r2(&ehdr->e32.e_##fn_name);		\
+}							\
+							\
+static uint16_t ehdr_##fn_name(Elf_Ehdr *ehdr)		\
+{							\
+	return e.ehdr_##fn_name(ehdr);			\
 }
 
 EHDR_HALF(shentsize)
@@ -119,6 +148,11 @@  static uint32_t shdr64_##fn_name(Elf_Shdr *shdr)	\
 static uint32_t shdr32_##fn_name(Elf_Shdr *shdr)	\
 {							\
 	return r(&shdr->e32.sh_##fn_name);		\
+}							\
+							\
+static uint32_t shdr_##fn_name(Elf_Shdr *shdr)		\
+{							\
+	return e.shdr_##fn_name(shdr);			\
 }
 
 #define SHDR_ADDR(fn_name)				\
@@ -130,6 +164,11 @@  static uint64_t shdr64_##fn_name(Elf_Shdr *shdr)	\
 static uint64_t shdr32_##fn_name(Elf_Shdr *shdr)	\
 {							\
 	return r(&shdr->e32.sh_##fn_name);		\
+}							\
+							\
+static uint64_t shdr_##fn_name(Elf_Shdr *shdr)		\
+{							\
+	return e.shdr_##fn_name(shdr);			\
 }
 
 #define SHDR_WORD(fn_name)				\
@@ -141,6 +180,10 @@  static uint32_t shdr64_##fn_name(Elf_Shdr *shdr)	\
 static uint32_t shdr32_##fn_name(Elf_Shdr *shdr)	\
 {							\
 	return r(&shdr->e32.sh_##fn_name);		\
+}							\
+static uint32_t shdr_##fn_name(Elf_Shdr *shdr)		\
+{							\
+	return e.shdr_##fn_name(shdr);			\
 }
 
 SHDR_ADDR(addr)
@@ -161,6 +204,11 @@  static uint64_t sym64_##fn_name(Elf_Sym *sym)	\
 static uint64_t sym32_##fn_name(Elf_Sym *sym)	\
 {						\
 	return r(&sym->e32.st_##fn_name);	\
+}						\
+						\
+static uint64_t sym_##fn_name(Elf_Sym *sym)	\
+{						\
+	return e.sym_##fn_name(sym);		\
 }
 
 #define SYM_WORD(fn_name)			\
@@ -172,6 +220,11 @@  static uint32_t sym64_##fn_name(Elf_Sym *sym)	\
 static uint32_t sym32_##fn_name(Elf_Sym *sym)	\
 {						\
 	return r(&sym->e32.st_##fn_name);	\
+}						\
+						\
+static uint32_t sym_##fn_name(Elf_Sym *sym)	\
+{						\
+	return e.sym_##fn_name(sym);		\
 }
 
 #define SYM_HALF(fn_name)			\
@@ -183,6 +236,11 @@  static uint16_t sym64_##fn_name(Elf_Sym *sym)	\
 static uint16_t sym32_##fn_name(Elf_Sym *sym)	\
 {						\
 	return r2(&sym->e32.st_##fn_name);	\
+}						\
+						\
+static uint16_t sym_##fn_name(Elf_Sym *sym)	\
+{						\
+	return e.sym_##fn_name(sym);		\
 }
 
 static uint8_t sym64_type(Elf_Sym *sym)
@@ -195,6 +253,11 @@  static uint8_t sym32_type(Elf_Sym *sym)
 	return ELF32_ST_TYPE(sym->e32.st_info);
 }
 
+static uint8_t sym_type(Elf_Sym *sym)
+{
+	return e.sym_type(sym);
+}
+
 SYM_ADDR(value)
 SYM_WORD(name)
 SYM_HALF(shndx)
@@ -322,29 +385,16 @@  static int compare_extable_64(const void *a, const void *b)
 	return av > bv;
 }
 
+static int compare_extable(const void *a, const void *b)
+{
+	return e.compare_extable(a, b);
+}
+
 static inline void *get_index(void *start, int entsize, int index)
 {
 	return start + (entsize * index);
 }
 
-
-static int (*compare_extable)(const void *a, const void *b);
-static uint64_t (*ehdr_shoff)(Elf_Ehdr *ehdr);
-static uint16_t (*ehdr_shstrndx)(Elf_Ehdr *ehdr);
-static uint16_t (*ehdr_shentsize)(Elf_Ehdr *ehdr);
-static uint16_t (*ehdr_shnum)(Elf_Ehdr *ehdr);
-static uint64_t (*shdr_addr)(Elf_Shdr *shdr);
-static uint64_t (*shdr_offset)(Elf_Shdr *shdr);
-static uint64_t (*shdr_size)(Elf_Shdr *shdr);
-static uint64_t (*shdr_entsize)(Elf_Shdr *shdr);
-static uint32_t (*shdr_link)(Elf_Shdr *shdr);
-static uint32_t (*shdr_name)(Elf_Shdr *shdr);
-static uint32_t (*shdr_type)(Elf_Shdr *shdr);
-static uint8_t (*sym_type)(Elf_Sym *sym);
-static uint32_t (*sym_name)(Elf_Sym *sym);
-static uint64_t (*sym_value)(Elf_Sym *sym);
-static uint16_t (*sym_shndx)(Elf_Sym *sym);
-
 static int extable_ent_size;
 static int long_size;
 
@@ -864,7 +914,30 @@  static int do_file(char const *const fname, void *addr)
 	}
 
 	switch (ehdr->e32.e_ident[EI_CLASS]) {
-	case ELFCLASS32:
+	case ELFCLASS32: {
+		struct elf_funcs efuncs = {
+			.compare_extable	= compare_extable_32,
+			.ehdr_shoff		= ehdr32_shoff,
+			.ehdr_shentsize		= ehdr32_shentsize,
+			.ehdr_shstrndx		= ehdr32_shstrndx,
+			.ehdr_shnum		= ehdr32_shnum,
+			.shdr_addr		= shdr32_addr,
+			.shdr_offset		= shdr32_offset,
+			.shdr_link		= shdr32_link,
+			.shdr_size		= shdr32_size,
+			.shdr_name		= shdr32_name,
+			.shdr_type		= shdr32_type,
+			.shdr_entsize		= shdr32_entsize,
+			.sym_type		= sym32_type,
+			.sym_name		= sym32_name,
+			.sym_value		= sym32_value,
+			.sym_shndx		= sym32_shndx,
+		};
+
+		e = efuncs;
+		long_size		= 4;
+		extable_ent_size	= 8;
+
 		if (r2(&ehdr->e32.e_ehsize) != sizeof(Elf32_Ehdr) ||
 		    r2(&ehdr->e32.e_shentsize) != sizeof(Elf32_Shdr)) {
 			fprintf(stderr,
@@ -872,26 +945,32 @@  static int do_file(char const *const fname, void *addr)
 			return -1;
 		}
 
-		compare_extable		= compare_extable_32;
-		ehdr_shoff		= ehdr32_shoff;
-		ehdr_shentsize		= ehdr32_shentsize;
-		ehdr_shstrndx		= ehdr32_shstrndx;
-		ehdr_shnum		= ehdr32_shnum;
-		shdr_addr		= shdr32_addr;
-		shdr_offset		= shdr32_offset;
-		shdr_link		= shdr32_link;
-		shdr_size		= shdr32_size;
-		shdr_name		= shdr32_name;
-		shdr_type		= shdr32_type;
-		shdr_entsize		= shdr32_entsize;
-		sym_type		= sym32_type;
-		sym_name		= sym32_name;
-		sym_value		= sym32_value;
-		sym_shndx		= sym32_shndx;
-		long_size		= 4;
-		extable_ent_size	= 8;
+		}
 		break;
-	case ELFCLASS64:
+	case ELFCLASS64: {
+		struct elf_funcs efuncs = {
+			.compare_extable	= compare_extable_64,
+			.ehdr_shoff		= ehdr64_shoff,
+			.ehdr_shentsize		= ehdr64_shentsize,
+			.ehdr_shstrndx		= ehdr64_shstrndx,
+			.ehdr_shnum		= ehdr64_shnum,
+			.shdr_addr		= shdr64_addr,
+			.shdr_offset		= shdr64_offset,
+			.shdr_link		= shdr64_link,
+			.shdr_size		= shdr64_size,
+			.shdr_name		= shdr64_name,
+			.shdr_type		= shdr64_type,
+			.shdr_entsize		= shdr64_entsize,
+			.sym_type		= sym64_type,
+			.sym_name		= sym64_name,
+			.sym_value		= sym64_value,
+			.sym_shndx		= sym64_shndx,
+		};
+
+		e = efuncs;
+		long_size		= 8;
+		extable_ent_size	= 16;
+
 		if (r2(&ehdr->e64.e_ehsize) != sizeof(Elf64_Ehdr) ||
 		    r2(&ehdr->e64.e_shentsize) != sizeof(Elf64_Shdr)) {
 			fprintf(stderr,
@@ -900,25 +979,7 @@  static int do_file(char const *const fname, void *addr)
 			return -1;
 		}
 
-		compare_extable		= compare_extable_64;
-		ehdr_shoff		= ehdr64_shoff;
-		ehdr_shentsize		= ehdr64_shentsize;
-		ehdr_shstrndx		= ehdr64_shstrndx;
-		ehdr_shnum		= ehdr64_shnum;
-		shdr_addr		= shdr64_addr;
-		shdr_offset		= shdr64_offset;
-		shdr_link		= shdr64_link;
-		shdr_size		= shdr64_size;
-		shdr_name		= shdr64_name;
-		shdr_type		= shdr64_type;
-		shdr_entsize		= shdr64_entsize;
-		sym_type		= sym64_type;
-		sym_name		= sym64_name;
-		sym_value		= sym64_value;
-		sym_shndx		= sym64_shndx;
-		long_size		= 8;
-		extable_ent_size	= 16;
-
+		}
 		break;
 	default:
 		fprintf(stderr, "unrecognized ELF class %d %s\n",