From: Masahiro Yamada <masahiroy@kernel.org>
To: linux-kbuild@vger.kernel.org
Cc: linux-kernel@vger.kernel.org,
Nathan Chancellor <nathan@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Nicolas Pitre <npitre@baylibre.com>,
Nicolas Schier <nicolas@fjasle.eu>,
Masahiro Yamada <masahiroy@kernel.org>
Subject: [PATCH v4 10/21] modpost: simplify find_elf_symbol()
Date: Sun, 14 May 2023 05:44:51 +0900 [thread overview]
Message-ID: <20230513204502.1593923-11-masahiroy@kernel.org> (raw)
In-Reply-To: <20230513204502.1593923-1-masahiroy@kernel.org>
I do not know why commit 157c23c80eed ("kbuild: use simpler section
mismatch warnings in modpost") is only applicable to find_elf_symbol2().
Simplify find_elf_symbol() based on find_elf_symbol2().
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
scripts/mod/modpost.c | 64 +++++++++----------------------------------
1 file changed, 13 insertions(+), 51 deletions(-)
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 3b7b78e69137..b4fa9e0be4d1 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -1117,57 +1117,7 @@ static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
return !is_mapping_symbol(name);
}
-/**
- * Find symbol based on relocation record info.
- * In some cases the symbol supplied is a valid symbol so
- * return refsym. If st_name != 0 we assume this is a valid symbol.
- * In other cases the symbol needs to be looked up in the symbol table
- * based on section and address.
- * **/
-static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
- Elf_Sym *relsym)
-{
- Elf_Sym *sym;
- Elf_Sym *near = NULL;
- Elf64_Sword distance = 20;
- Elf64_Sword d;
- unsigned int relsym_secindex;
-
- if (relsym->st_name != 0)
- return relsym;
-
- relsym_secindex = get_secindex(elf, relsym);
- for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
- if (get_secindex(elf, sym) != relsym_secindex)
- continue;
- if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
- continue;
- if (!is_valid_name(elf, sym))
- continue;
- if (sym->st_value == addr)
- return sym;
- /* Find a symbol nearby - addr are maybe negative */
- d = sym->st_value - addr;
- if (d < 0)
- d = addr - sym->st_value;
- if (d < distance) {
- distance = d;
- near = sym;
- }
- }
- /* We need a close match */
- if (distance < 20)
- return near;
- else
- return NULL;
-}
-
-/*
- * Find symbols before or equal addr and after addr - in the section sec.
- * If we find two symbols with equal offset prefer one with a valid name.
- * The ELF format may have a better way to detect what type of symbol
- * it is, but this works for now.
- **/
+/* Look up the nearest symbol based on the section and the address */
static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
unsigned int secndx)
{
@@ -1178,6 +1128,8 @@ static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
if (get_secindex(elf, sym) != secndx)
continue;
+ if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
+ continue;
if (!is_valid_name(elf, sym))
continue;
if (sym->st_value <= addr && addr - sym->st_value <= distance) {
@@ -1188,6 +1140,16 @@ static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
return near;
}
+static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym)
+{
+ /* If the supplied symbol is valid, return it */
+ if (sym->st_name != 0)
+ return sym;
+
+ /* Otherwise, look up a better symbol */
+ return find_elf_symbol2(elf, addr, get_secindex(elf, sym));
+}
+
static bool is_executable_section(struct elf_info *elf, unsigned int secndx)
{
if (secndx > elf->num_sections)
--
2.39.2
next prev parent reply other threads:[~2023-05-13 20:46 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-13 20:44 [PATCH v4 00/21] Unify <linux/export.h> and <asm/export.h>, remove EXPORT_DATA_SYMBOL(), faster TRIM_UNUSED_KSYMS Masahiro Yamada
2023-05-13 20:44 ` [PATCH v4 01/21] modpost: remove broken calculation of exception_table_entry size Masahiro Yamada
2023-05-13 20:44 ` [PATCH v4 02/21] modpost: remove fromsym info in __ex_table section mismatch warning Masahiro Yamada
2023-05-13 20:44 ` [PATCH v4 03/21] modpost: remove get_prettyname() Masahiro Yamada
2023-05-13 20:44 ` [PATCH v4 04/21] modpost: squash report_extable_warnings() into extable_mismatch_handler() Masahiro Yamada
2023-05-13 20:44 ` [PATCH v4 05/21] modpost: squash report_sec_mismatch() into default_mismatch_handler() Masahiro Yamada
2023-05-13 20:44 ` [PATCH v4 06/21] modpost: clean up is_executable_section() Masahiro Yamada
2023-05-13 20:44 ` [PATCH v4 07/21] modpost: squash extable_mismatch_handler() into default_mismatch_handler() Masahiro Yamada
2023-05-13 20:44 ` [PATCH v4 08/21] modpost: pass 'tosec' down to default_mismatch_handler() Masahiro Yamada
2023-05-13 20:44 ` [PATCH v4 09/21] modpost: pass section index to find_elf_symbol2() Masahiro Yamada
2023-05-13 20:44 ` Masahiro Yamada [this message]
2023-05-13 20:44 ` [PATCH v4 11/21] modpost: rename find_elf_symbol() and find_elf_symbol2() Masahiro Yamada
2023-05-13 20:44 ` [PATCH v4 12/21] modpost: unify 'sym' and 'to' in default_mismatch_handler() Masahiro Yamada
2023-05-13 20:44 ` [PATCH v4 13/21] modpost: replace r->r_offset, r->r_addend with faddr, taddr Masahiro Yamada
2023-05-13 20:44 ` [PATCH v4 14/21] modpost: remove is_shndx_special() check from section_rel(a) Masahiro Yamada
2023-05-13 20:44 ` [PATCH v4 15/21] modpost: pass struct module pointer to check_section_mismatch() Masahiro Yamada
2023-05-13 20:44 ` [PATCH v4 16/21] kbuild: generate KSYMTAB entries by modpost Masahiro Yamada
2023-05-13 20:44 ` [PATCH v4 17/21] ia64,export.h: replace EXPORT_DATA_SYMBOL* with EXPORT_SYMBOL* Masahiro Yamada
2023-05-13 20:44 ` [PATCH v4 18/21] modpost: check static EXPORT_SYMBOL* by modpost again Masahiro Yamada
2023-05-13 20:45 ` [PATCH v4 19/21] modpost: squash sym_update_namespace() into sym_add_exported() Masahiro Yamada
2023-05-13 20:45 ` [PATCH v4 20/21] modpost: use null string instead of NULL pointer for default namespace Masahiro Yamada
2023-05-13 20:45 ` [PATCH v4 21/21] kbuild: implement CONFIG_TRIM_UNUSED_KSYMS without recursion Masahiro Yamada
2023-05-14 12:43 ` [PATCH v4 00/21] Unify <linux/export.h> and <asm/export.h>, remove EXPORT_DATA_SYMBOL(), faster TRIM_UNUSED_KSYMS Masahiro Yamada
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