Commit 8045b8f0 authored by Thomas Weißschuh's avatar Thomas Weißschuh Committed by Josh Poimboeuf

objtool: Allocate multiple structures with calloc()

By using calloc() instead of malloc() in a loop, libc does not have to
keep around bookkeeping information for each single structure.

This reduces maximum memory usage while processing vmlinux.o from
3153325 KB to 3035668 KB (-3.7%) on my notebooks "localmodconfig".

Note this introduces memory leaks, because some additional structs get
added to the lists later after reading the symbols and sections from the
original object.  Luckily we don't really care about memory leaks in
objtool.
Signed-off-by: default avatarThomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/r/20221216-objtool-memory-v2-3-17968f85a464@weissschuh.netSigned-off-by: default avatarJosh Poimboeuf <jpoimboe@kernel.org>
parent cfd66e81
...@@ -284,13 +284,13 @@ static int read_sections(struct elf *elf) ...@@ -284,13 +284,13 @@ static int read_sections(struct elf *elf)
!elf_alloc_hash(section_name, sections_nr)) !elf_alloc_hash(section_name, sections_nr))
return -1; return -1;
elf->section_data = calloc(sections_nr, sizeof(*sec));
if (!elf->section_data) {
perror("calloc");
return -1;
}
for (i = 0; i < sections_nr; i++) { for (i = 0; i < sections_nr; i++) {
sec = malloc(sizeof(*sec)); sec = &elf->section_data[i];
if (!sec) {
perror("malloc");
return -1;
}
memset(sec, 0, sizeof(*sec));
INIT_LIST_HEAD(&sec->symbol_list); INIT_LIST_HEAD(&sec->symbol_list);
INIT_LIST_HEAD(&sec->reloc_list); INIT_LIST_HEAD(&sec->reloc_list);
...@@ -422,13 +422,13 @@ static int read_symbols(struct elf *elf) ...@@ -422,13 +422,13 @@ static int read_symbols(struct elf *elf)
!elf_alloc_hash(symbol_name, symbols_nr)) !elf_alloc_hash(symbol_name, symbols_nr))
return -1; return -1;
elf->symbol_data = calloc(symbols_nr, sizeof(*sym));
if (!elf->symbol_data) {
perror("calloc");
return -1;
}
for (i = 0; i < symbols_nr; i++) { for (i = 0; i < symbols_nr; i++) {
sym = malloc(sizeof(*sym)); sym = &elf->symbol_data[i];
if (!sym) {
perror("malloc");
return -1;
}
memset(sym, 0, sizeof(*sym));
sym->idx = i; sym->idx = i;
...@@ -918,13 +918,13 @@ static int read_relocs(struct elf *elf) ...@@ -918,13 +918,13 @@ static int read_relocs(struct elf *elf)
sec->base->reloc = sec; sec->base->reloc = sec;
nr_reloc = 0; nr_reloc = 0;
sec->reloc_data = calloc(sec->sh.sh_size / sec->sh.sh_entsize, sizeof(*reloc));
if (!sec->reloc_data) {
perror("calloc");
return -1;
}
for (i = 0; i < sec->sh.sh_size / sec->sh.sh_entsize; i++) { for (i = 0; i < sec->sh.sh_size / sec->sh.sh_entsize; i++) {
reloc = malloc(sizeof(*reloc)); reloc = &sec->reloc_data[i];
if (!reloc) {
perror("malloc");
return -1;
}
memset(reloc, 0, sizeof(*reloc));
switch (sec->sh.sh_type) { switch (sec->sh.sh_type) {
case SHT_REL: case SHT_REL:
if (read_rel_reloc(sec, i, reloc, &symndx)) if (read_rel_reloc(sec, i, reloc, &symndx))
...@@ -1453,16 +1453,16 @@ void elf_close(struct elf *elf) ...@@ -1453,16 +1453,16 @@ void elf_close(struct elf *elf)
list_for_each_entry_safe(sym, tmpsym, &sec->symbol_list, list) { list_for_each_entry_safe(sym, tmpsym, &sec->symbol_list, list) {
list_del(&sym->list); list_del(&sym->list);
hash_del(&sym->hash); hash_del(&sym->hash);
free(sym);
} }
list_for_each_entry_safe(reloc, tmpreloc, &sec->reloc_list, list) { list_for_each_entry_safe(reloc, tmpreloc, &sec->reloc_list, list) {
list_del(&reloc->list); list_del(&reloc->list);
hash_del(&reloc->hash); hash_del(&reloc->hash);
free(reloc);
} }
list_del(&sec->list); list_del(&sec->list);
free(sec); free(sec->reloc_data);
} }
free(elf->symbol_data);
free(elf->section_data);
free(elf); free(elf);
} }
...@@ -39,6 +39,7 @@ struct section { ...@@ -39,6 +39,7 @@ struct section {
char *name; char *name;
int idx; int idx;
bool changed, text, rodata, noinstr, init, truncate; bool changed, text, rodata, noinstr, init, truncate;
struct reloc *reloc_data;
}; };
struct symbol { struct symbol {
...@@ -104,6 +105,9 @@ struct elf { ...@@ -104,6 +105,9 @@ struct elf {
struct hlist_head *section_hash; struct hlist_head *section_hash;
struct hlist_head *section_name_hash; struct hlist_head *section_name_hash;
struct hlist_head *reloc_hash; struct hlist_head *reloc_hash;
struct section *section_data;
struct symbol *symbol_data;
}; };
#define OFFSET_STRIDE_BITS 4 #define OFFSET_STRIDE_BITS 4
......
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