Skip to content

Commit b055f4c

Browse files
rostedtrostedt
committed
sorttable: Move ELF parsing into scripts/elf-parse.[ch]
In order to share the elf parsing that is in sorttable.c so that other programs could use the same code, move it into elf-parse.c and elf-parse.h. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nicolas Schier <nicolas.schier@linux.dev> Cc: Nick Desaulniers <nick.desaulniers+lkml@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Link: https://lore.kernel.org/20251022004452.752298788@kernel.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
1 parent 211ddde commit b055f4c

4 files changed

Lines changed: 540 additions & 443 deletions

File tree

‎scripts/Makefile‎

Lines changed: 3 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -12,6 +12,8 @@ hostprogs-always-$(CONFIG_SYSTEM_EXTRA_CERTIFICATE) += insert-sys-cert
1212
hostprogs-always-$(CONFIG_RUST_KERNEL_DOCTESTS) += rustdoc_test_builder
1313
hostprogs-always-$(CONFIG_RUST_KERNEL_DOCTESTS) += rustdoc_test_gen
1414

15+
sorttable-objs := sorttable.o elf-parse.o
16+
1517
ifneq ($(or $(CONFIG_X86_64),$(CONFIG_X86_32)),)
1618
always-$(CONFIG_RUST) += target.json
1719
filechk_rust_target = $< < include/config/auto.conf
@@ -25,6 +27,7 @@ generate_rust_target-rust := y
2527
rustdoc_test_builder-rust := y
2628
rustdoc_test_gen-rust := y
2729

30+
HOSTCFLAGS_elf-parse.o = -I$(srctree)/tools/include
2831
HOSTCFLAGS_sorttable.o = -I$(srctree)/tools/include
2932
HOSTLDLIBS_sorttable = -lpthread
3033
HOSTCFLAGS_asn1_compiler.o = -I$(srctree)/include

‎scripts/elf-parse.c‎

Lines changed: 198 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,198 @@
1+
#include <sys/types.h>
2+
#include <sys/mman.h>
3+
#include <sys/stat.h>
4+
#include <fcntl.h>
5+
#include <stdio.h>
6+
#include <stdlib.h>
7+
#include <stdbool.h>
8+
#include <string.h>
9+
#include <unistd.h>
10+
#include <errno.h>
11+
12+
#include "elf-parse.h"
13+
14+
struct elf_funcs elf_parser;
15+
16+
/*
17+
* Get the whole file as a programming convenience in order to avoid
18+
* malloc+lseek+read+free of many pieces. If successful, then mmap
19+
* avoids copying unused pieces; else just read the whole file.
20+
* Open for both read and write.
21+
*/
22+
static void *map_file(char const *fname, size_t *size)
23+
{
24+
int fd;
25+
struct stat sb;
26+
void *addr = NULL;
27+
28+
fd = open(fname, O_RDWR);
29+
if (fd < 0) {
30+
perror(fname);
31+
return NULL;
32+
}
33+
if (fstat(fd, &sb) < 0) {
34+
perror(fname);
35+
goto out;
36+
}
37+
if (!S_ISREG(sb.st_mode)) {
38+
fprintf(stderr, "not a regular file: %s\n", fname);
39+
goto out;
40+
}
41+
42+
addr = mmap(0, sb.st_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
43+
if (addr == MAP_FAILED) {
44+
fprintf(stderr, "Could not mmap file: %s\n", fname);
45+
goto out;
46+
}
47+
48+
*size = sb.st_size;
49+
50+
out:
51+
close(fd);
52+
return addr;
53+
}
54+
55+
static int elf_parse(const char *fname, void *addr, uint32_t types)
56+
{
57+
Elf_Ehdr *ehdr = addr;
58+
uint16_t type;
59+
60+
switch (ehdr->e32.e_ident[EI_DATA]) {
61+
case ELFDATA2LSB:
62+
elf_parser.r = rle;
63+
elf_parser.r2 = r2le;
64+
elf_parser.r8 = r8le;
65+
elf_parser.w = wle;
66+
elf_parser.w8 = w8le;
67+
break;
68+
case ELFDATA2MSB:
69+
elf_parser.r = rbe;
70+
elf_parser.r2 = r2be;
71+
elf_parser.r8 = r8be;
72+
elf_parser.w = wbe;
73+
elf_parser.w8 = w8be;
74+
break;
75+
default:
76+
fprintf(stderr, "unrecognized ELF data encoding %d: %s\n",
77+
ehdr->e32.e_ident[EI_DATA], fname);
78+
return -1;
79+
}
80+
81+
if (memcmp(ELFMAG, ehdr->e32.e_ident, SELFMAG) != 0 ||
82+
ehdr->e32.e_ident[EI_VERSION] != EV_CURRENT) {
83+
fprintf(stderr, "unrecognized ELF file %s\n", fname);
84+
return -1;
85+
}
86+
87+
type = elf_parser.r2(&ehdr->e32.e_type);
88+
if (!((1 << type) & types)) {
89+
fprintf(stderr, "Invalid ELF type file %s\n", fname);
90+
return -1;
91+
}
92+
93+
switch (ehdr->e32.e_ident[EI_CLASS]) {
94+
case ELFCLASS32: {
95+
elf_parser.ehdr_shoff = ehdr32_shoff;
96+
elf_parser.ehdr_shentsize = ehdr32_shentsize;
97+
elf_parser.ehdr_shstrndx = ehdr32_shstrndx;
98+
elf_parser.ehdr_shnum = ehdr32_shnum;
99+
elf_parser.shdr_addr = shdr32_addr;
100+
elf_parser.shdr_offset = shdr32_offset;
101+
elf_parser.shdr_link = shdr32_link;
102+
elf_parser.shdr_size = shdr32_size;
103+
elf_parser.shdr_name = shdr32_name;
104+
elf_parser.shdr_type = shdr32_type;
105+
elf_parser.shdr_entsize = shdr32_entsize;
106+
elf_parser.sym_type = sym32_type;
107+
elf_parser.sym_name = sym32_name;
108+
elf_parser.sym_value = sym32_value;
109+
elf_parser.sym_shndx = sym32_shndx;
110+
elf_parser.rela_offset = rela32_offset;
111+
elf_parser.rela_info = rela32_info;
112+
elf_parser.rela_addend = rela32_addend;
113+
elf_parser.rela_write_addend = rela32_write_addend;
114+
115+
if (elf_parser.r2(&ehdr->e32.e_ehsize) != sizeof(Elf32_Ehdr) ||
116+
elf_parser.r2(&ehdr->e32.e_shentsize) != sizeof(Elf32_Shdr)) {
117+
fprintf(stderr,
118+
"unrecognized ET_EXEC/ET_DYN file: %s\n", fname);
119+
return -1;
120+
}
121+
122+
}
123+
break;
124+
case ELFCLASS64: {
125+
elf_parser.ehdr_shoff = ehdr64_shoff;
126+
elf_parser.ehdr_shentsize = ehdr64_shentsize;
127+
elf_parser.ehdr_shstrndx = ehdr64_shstrndx;
128+
elf_parser.ehdr_shnum = ehdr64_shnum;
129+
elf_parser.shdr_addr = shdr64_addr;
130+
elf_parser.shdr_offset = shdr64_offset;
131+
elf_parser.shdr_link = shdr64_link;
132+
elf_parser.shdr_size = shdr64_size;
133+
elf_parser.shdr_name = shdr64_name;
134+
elf_parser.shdr_type = shdr64_type;
135+
elf_parser.shdr_entsize = shdr64_entsize;
136+
elf_parser.sym_type = sym64_type;
137+
elf_parser.sym_name = sym64_name;
138+
elf_parser.sym_value = sym64_value;
139+
elf_parser.sym_shndx = sym64_shndx;
140+
elf_parser.rela_offset = rela64_offset;
141+
elf_parser.rela_info = rela64_info;
142+
elf_parser.rela_addend = rela64_addend;
143+
elf_parser.rela_write_addend = rela64_write_addend;
144+
145+
if (elf_parser.r2(&ehdr->e64.e_ehsize) != sizeof(Elf64_Ehdr) ||
146+
elf_parser.r2(&ehdr->e64.e_shentsize) != sizeof(Elf64_Shdr)) {
147+
fprintf(stderr,
148+
"unrecognized ET_EXEC/ET_DYN file: %s\n",
149+
fname);
150+
return -1;
151+
}
152+
153+
}
154+
break;
155+
default:
156+
fprintf(stderr, "unrecognized ELF class %d %s\n",
157+
ehdr->e32.e_ident[EI_CLASS], fname);
158+
return -1;
159+
}
160+
return 0;
161+
}
162+
163+
int elf_map_machine(void *addr)
164+
{
165+
Elf_Ehdr *ehdr = addr;
166+
167+
return elf_parser.r2(&ehdr->e32.e_machine);
168+
}
169+
170+
int elf_map_long_size(void *addr)
171+
{
172+
Elf_Ehdr *ehdr = addr;
173+
174+
return ehdr->e32.e_ident[EI_CLASS] == ELFCLASS32 ? 4 : 8;
175+
}
176+
177+
void *elf_map(char const *fname, size_t *size, uint32_t types)
178+
{
179+
void *addr;
180+
int ret;
181+
182+
addr = map_file(fname, size);
183+
if (!addr)
184+
return NULL;
185+
186+
ret = elf_parse(fname, addr, types);
187+
if (ret < 0) {
188+
elf_unmap(addr, *size);
189+
return NULL;
190+
}
191+
192+
return addr;
193+
}
194+
195+
void elf_unmap(void *addr, size_t size)
196+
{
197+
munmap(addr, size);
198+
}

0 commit comments

Comments
 (0)