scripts/sorttable: Convert Elf_Sym MACRO over to a union

In order to remove the double #include of sorttable.h for 64 and 32 bit
to create duplicate functions for both, replace the Elf_Sym macro with a
union that defines both Elf64_Sym and Elf32_Sym, with field e64 for the
64bit version, and e32 for the 32bit version.

It can then use the macro etype to get the proper value.

This will eventually be replaced with just single functions that can
handle both 32bit and 64bit ELF parsing.

Cc: bpf <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Masahiro Yamada <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Cc: Nicolas Schier <[email protected]>
Cc: Zheng Yejian <[email protected]>
Cc: Martin  Kelly <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Link: https://lore.kernel.org/[email protected]
Signed-off-by: Steven Rostedt (Google) <[email protected]>

Author: rostedt

scripts/sorttable.c

@@ -74,6 +74,11 @@ typedef union {
 	Elf64_Shdr	e64;
 } Elf_Shdr;
 
+typedef union {
+	Elf32_Sym	e32;
+	Elf64_Sym	e64;
+} Elf_Sym;
+
 static uint32_t (*r)(const uint32_t *);
 static uint16_t (*r2)(const uint16_t *);
 static uint64_t (*r8)(const uint64_t *);

scripts/sorttable.h

@@ -23,7 +23,6 @@
 #undef sort_mcount_loc
 #undef elf_mcount_loc
 #undef do_sort
-#undef Elf_Sym
 #undef ELF_ST_TYPE
 #undef uint_t
 #undef _r
@@ -36,7 +35,6 @@
 # define sort_mcount_loc	sort_mcount_loc_64
 # define elf_mcount_loc		elf_mcount_loc_64
 # define do_sort		do_sort_64
-# define Elf_Sym		Elf64_Sym
 # define ELF_ST_TYPE		ELF64_ST_TYPE
 # define uint_t			uint64_t
 # define _r			r8
@@ -48,7 +46,6 @@
 # define sort_mcount_loc	sort_mcount_loc_32
 # define elf_mcount_loc		elf_mcount_loc_32
 # define do_sort		do_sort_32
-# define Elf_Sym		Elf32_Sym
 # define ELF_ST_TYPE		ELF32_ST_TYPE
 # define uint_t			uint32_t
 # define _r			r
@@ -230,10 +227,13 @@ static int do_sort(Elf_Ehdr *ehdr,
 	Elf_Sym *sort_needed_sym = NULL;
 	Elf_Shdr *sort_needed_sec;
 	uint32_t *sort_needed_loc;
+	void *sym_start;
+	void *sym_end;
 	const char *secstrings;
 	const char *strtab;
 	char *extab_image;
 	int sort_need_index;
+	int symentsize;
 	int shentsize;
 	int idx;
 	int i;
@@ -376,12 +376,15 @@ static int do_sort(Elf_Ehdr *ehdr,
 	}
 
 	/* find the flag main_extable_sort_needed */
-	for (sym = (void *)ehdr + _r(&symtab_sec->etype.sh_offset);
-	     sym < sym + _r(&symtab_sec->etype.sh_size) / sizeof(Elf_Sym);
-	     sym++) {
-		if (ELF_ST_TYPE(sym->st_info) != STT_OBJECT)
+	sym_start = (void *)ehdr + _r(&symtab_sec->etype.sh_offset);
+	sym_end = sym_start + _r(&symtab_sec->etype.sh_size);
+	symentsize = _r(&symtab_sec->etype.sh_entsize);
+
+	for (sym = sym_start; (void *)sym + symentsize < sym_end;
+	     sym = (void *)sym + symentsize) {
+		if (ELF_ST_TYPE(sym->etype.st_info) != STT_OBJECT)
 			continue;
-		if (!strcmp(strtab + r(&sym->st_name),
+		if (!strcmp(strtab + r(&sym->etype.st_name),
 			    "main_extable_sort_needed")) {
 			sort_needed_sym = sym;
 			break;
@@ -395,13 +398,13 @@ static int do_sort(Elf_Ehdr *ehdr,
 		goto out;
 	}
 
-	sort_need_index = get_secindex(r2(&sym->st_shndx),
-				       sort_needed_sym - symtab,
+	sort_need_index = get_secindex(r2(&sym->etype.st_shndx),
+				       ((void *)sort_needed_sym - (void *)symtab) / symentsize,
 				       symtab_shndx);
 	sort_needed_sec = get_index(shdr_start, shentsize, sort_need_index);
 	sort_needed_loc = (void *)ehdr +
 		_r(&sort_needed_sec->etype.sh_offset) +
-		_r(&sort_needed_sym->st_value) -
+		_r(&sort_needed_sym->etype.st_value) -
 		_r(&sort_needed_sec->etype.sh_addr);
 
 	/* extable has been sorted, clear the flag */