From: Peter Zijlstra <peterz@infradead.org>
To: tglx@linutronix.de, jpoimboe@redhat.com
Cc: linux-kernel@vger.kernel.org, x86@kernel.org,
peterz@infradead.org, mhiramat@kernel.org, mbenes@suse.cz,
brgerst@gmail.com
Subject: [PATCH v2 07/19] objtool: Optimize find_section_by_index()
Date: Tue, 17 Mar 2020 18:02:41 +0100 [thread overview]
Message-ID: <20200317170910.178947741@infradead.org> (raw)
In-Reply-To: 20200317170234.897520633@infradead.org
In order to avoid a linear search (over 20k entries), add an
section_hash to the elf object.
This reduces objtool on vmlinux.o from a few minutes to around 45
seconds.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
tools/objtool/elf.c | 13 ++++++++-----
tools/objtool/elf.h | 2 ++
2 files changed, 10 insertions(+), 5 deletions(-)
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -38,7 +38,7 @@ static struct section *find_section_by_i
{
struct section *sec;
- list_for_each_entry(sec, &elf->sections, list)
+ hash_for_each_possible(elf->section_hash, sec, hash, idx)
if (sec->idx == idx)
return sec;
@@ -166,8 +166,6 @@ static int read_sections(struct elf *elf
INIT_LIST_HEAD(&sec->rela_list);
hash_init(sec->rela_hash);
- list_add_tail(&sec->list, &elf->sections);
-
s = elf_getscn(elf->elf, i);
if (!s) {
WARN_ELF("elf_getscn");
@@ -201,6 +199,9 @@ static int read_sections(struct elf *elf
}
}
sec->len = sec->sh.sh_size;
+
+ list_add_tail(&sec->list, &elf->sections);
+ hash_add(elf->section_hash, &sec->hash, sec->idx);
}
if (stats)
@@ -439,6 +440,7 @@ struct elf *elf_read(const char *name, i
memset(elf, 0, sizeof(*elf));
hash_init(elf->symbol_hash);
+ hash_init(elf->section_hash);
INIT_LIST_HEAD(&elf->sections);
elf->fd = open(name, flags);
@@ -501,8 +503,6 @@ struct section *elf_create_section(struc
INIT_LIST_HEAD(&sec->rela_list);
hash_init(sec->rela_hash);
- list_add_tail(&sec->list, &elf->sections);
-
s = elf_newscn(elf->elf);
if (!s) {
WARN_ELF("elf_newscn");
@@ -579,6 +579,9 @@ struct section *elf_create_section(struc
shstrtab->len += strlen(name) + 1;
shstrtab->changed = true;
+ list_add_tail(&sec->list, &elf->sections);
+ hash_add(elf->section_hash, &sec->hash, sec->idx);
+
return sec;
}
--- a/tools/objtool/elf.h
+++ b/tools/objtool/elf.h
@@ -25,6 +25,7 @@
struct section {
struct list_head list;
+ struct hlist_node hash;
GElf_Shdr sh;
struct list_head symbol_list;
struct list_head rela_list;
@@ -71,6 +72,7 @@ struct elf {
char *name;
struct list_head sections;
DECLARE_HASHTABLE(symbol_hash, 20);
+ DECLARE_HASHTABLE(section_hash, 16);
};
next prev parent reply other threads:[~2020-03-17 17:12 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-17 17:02 [PATCH v2 00/19] objtool: vmlinux.o and noinstr validation Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 01/19] objtool: Introduce validate_return() Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 02/19] objtool: Rename func_for_each_insn() Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 03/19] objtool: Rename func_for_each_insn_all() Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 04/19] x86/kexec: Use RIP relative addressing Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 05/19] objtool: Optimize find_symbol_by_index() Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 06/19] objtool: Add a statistics mode Peter Zijlstra
2020-03-17 17:02 ` Peter Zijlstra [this message]
2020-03-17 17:02 ` [PATCH v2 08/19] objtool: Optimize find_section_by_name() Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 09/19] objtool: Optimize find_symbol_*() and read_symbols() Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 10/19] objtool: Rename find_containing_func() Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 11/19] objtool: Resize insn_hash Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 12/19] objtool: Optimize find_symbol_by_name() Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 13/19] objtool: Optimize read_sections() Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 14/19] objtool: Delete cleanup() Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 15/19] objtool: Optimize find_rela_by_dest_range() Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 16/19] objtool: Implement noinstr validation Peter Zijlstra
2020-03-17 21:00 ` Josh Poimboeuf
2020-03-18 9:03 ` Peter Zijlstra
2020-03-18 10:06 ` Peter Zijlstra
2020-03-18 13:21 ` Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 17/19] objtool: Optimize !vmlinux.o again Peter Zijlstra
2020-03-18 13:20 ` Peter Zijlstra
2020-03-20 16:20 ` Miroslav Benes
2020-03-21 15:14 ` Peter Zijlstra
2020-03-21 16:11 ` Peter Zijlstra
2020-03-23 7:27 ` Miroslav Benes
2020-03-17 17:02 ` [PATCH v2 18/19] objtool: Use sec_offset_hash() for insn_hash Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 19/19] objtool: Detect loading function pointers across noinstr Peter Zijlstra
2020-03-17 23:39 ` kbuild test robot
2020-03-17 23:43 ` Nick Desaulniers
2020-03-18 11:02 ` Peter Zijlstra
2020-03-18 7:18 ` kbuild test robot
2020-03-17 21:05 ` [PATCH v2 00/19] objtool: vmlinux.o and noinstr validation Josh Poimboeuf
2020-03-18 13:18 ` [RFC][PATCH v2 20/19] kbuild/objtool: Add objtool-vmlinux.o pass Peter Zijlstra
2020-03-18 14:13 ` Peter Zijlstra
2020-03-18 18:34 ` Josh Poimboeuf
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