Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
objtool: Add elf_create_data()
In preparation for the objtool klp diff subcommand, refactor
elf_add_string() by adding a new elf_add_data() helper which allows the
adding of arbitrary data to a section.
Make both interfaces global so they can be used by the upcoming klp diff
code.
Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
+54
-22
+47
-19
tools/objtool/elf.c
+47
-19
tools/objtool/elf.c
···
18
18
#include <errno.h>
19
19
#include <linux/interval_tree_generic.h>
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20
#include <objtool/builtin.h>
21
-
22
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#include <objtool/elf.h>
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#include <objtool/warn.h>
23
+
24
+
#define ALIGN_UP(x, align_to) (((x) + ((align_to)-1)) & ~((align_to)-1))
24
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static inline u32 str_hash(const char *str)
26
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{
···
764
763
return 0;
765
764
}
766
765
767
-
static int elf_add_string(struct elf *elf, struct section *strtab, const char *str);
768
-
769
766
struct symbol *elf_create_symbol(struct elf *elf, const char *name,
770
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struct section *sec, unsigned int bind,
771
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unsigned int type, unsigned long offset,
···
1099
1100
return NULL;
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1101
}
1101
1102
1102
-
static int elf_add_string(struct elf *elf, struct section *strtab, const char *str)
1103
+
unsigned int elf_add_string(struct elf *elf, struct section *strtab, const char *str)
1103
1104
{
1104
-
Elf_Data *data;
1105
-
Elf_Scn *s;
1106
-
int len;
1105
+
unsigned int offset;
1107
1106
1108
1107
if (!strtab)
1109
1108
strtab = find_section_by_name(elf, ".strtab");
···
1110
1113
return -1;
1111
1114
}
1112
1115
1113
-
s = elf_getscn(elf->elf, strtab->idx);
1116
+
if (!strtab->sh.sh_addralign) {
1117
+
ERROR("'%s': invalid sh_addralign", strtab->name);
1118
+
return -1;
1119
+
}
1120
+
1121
+
offset = ALIGN_UP(strtab->sh.sh_size, strtab->sh.sh_addralign);
1122
+
1123
+
if (!elf_add_data(elf, strtab, str, strlen(str) + 1))
1124
+
return -1;
1125
+
1126
+
return offset;
1127
+
}
1128
+
1129
+
void *elf_add_data(struct elf *elf, struct section *sec, const void *data, size_t size)
1130
+
{
1131
+
unsigned long offset;
1132
+
Elf_Scn *s;
1133
+
1134
+
if (!sec->sh.sh_addralign) {
1135
+
ERROR("'%s': invalid sh_addralign", sec->name);
1136
+
return NULL;
1137
+
}
1138
+
1139
+
s = elf_getscn(elf->elf, sec->idx);
1114
1140
if (!s) {
1115
1141
ERROR_ELF("elf_getscn");
1116
-
return -1;
1142
+
return NULL;
1117
1143
}
1118
1144
1119
-
data = elf_newdata(s);
1120
-
if (!data) {
1145
+
sec->data = elf_newdata(s);
1146
+
if (!sec->data) {
1121
1147
ERROR_ELF("elf_newdata");
1122
-
return -1;
1148
+
return NULL;
1123
1149
}
1124
1150
1125
-
data->d_buf = strdup(str);
1126
-
data->d_size = strlen(str) + 1;
1127
-
data->d_align = 1;
1151
+
sec->data->d_buf = calloc(1, size);
1152
+
if (!sec->data->d_buf) {
1153
+
ERROR_GLIBC("calloc");
1154
+
return NULL;
1155
+
}
1128
1156
1129
-
len = strtab->sh.sh_size;
1130
-
strtab->sh.sh_size += data->d_size;
1157
+
if (data)
1158
+
memcpy(sec->data->d_buf, data, size);
1131
1159
1132
-
mark_sec_changed(elf, strtab, true);
1160
+
sec->data->d_size = size;
1161
+
sec->data->d_align = 1;
1133
1162
1134
-
return len;
1163
+
offset = ALIGN_UP(sec->sh.sh_size, sec->sh.sh_addralign);
1164
+
sec->sh.sh_size = offset + size;
1165
+
1166
+
mark_sec_changed(elf, sec, true);
1167
+
1168
+
return sec->data->d_buf;
1135
1169
}
1136
1170
1137
1171
struct section *elf_create_section(struct elf *elf, const char *name,
+7
-3
tools/objtool/include/objtool/elf.h
+7
-3
tools/objtool/include/objtool/elf.h
···
135
135
struct symbol *elf_create_prefix_symbol(struct elf *elf, struct symbol *orig,
136
136
size_t size);
137
137
138
+
void *elf_add_data(struct elf *elf, struct section *sec, const void *data,
139
+
size_t size);
140
+
141
+
unsigned int elf_add_string(struct elf *elf, struct section *strtab, const char *str);
138
142
139
143
struct reloc *elf_init_reloc_text_sym(struct elf *elf, struct section *sec,
140
144
unsigned long offset,
···
152
148
struct symbol *sym,
153
149
s64 addend);
154
150
155
-
int elf_write_insn(struct elf *elf, struct section *sec,
156
-
unsigned long offset, unsigned int len,
157
-
const char *insn);
151
+
int elf_write_insn(struct elf *elf, struct section *sec, unsigned long offset,
152
+
unsigned int len, const char *insn);
153
+
158
154
int elf_write(struct elf *elf);
159
155
void elf_close(struct elf *elf);
160
156