This helper function searches for a symbol with the provided name.
The symbol must be located in the specified section and within the
given distance from the target address.
In the expected use case, the min_distance is very small, so the
linear search will finish within a few iterations.
Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
---
scripts/mod/modpost.h | 3 +++
scripts/mod/symsearch.c | 44 +++++++++++++++++++++++++++++++++++++++++
2 files changed, 47 insertions(+)
diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h
index 9834ac44846d..43148b1a762b 100644
--- a/scripts/mod/modpost.h
+++ b/scripts/mod/modpost.h
@@ -186,6 +186,9 @@ void symsearch_finish(struct elf_info *elf);
Elf_Sym *symsearch_find_nearest(struct elf_info *elf, Elf_Addr addr,
unsigned int secndx, bool allow_negative,
Elf_Addr min_distance);
+Elf_Sym *symsearch_find_with_name(struct elf_info *elf, Elf_Addr addr,
+ unsigned int secndx, bool allow_negative,
+ Elf_Addr min_distance, const char *name);
/* file2alias.c */
void handle_moddevtable(struct module *mod, struct elf_info *info,
diff --git a/scripts/mod/symsearch.c b/scripts/mod/symsearch.c
index 13464e4f4d72..9101bb9584a4 100644
--- a/scripts/mod/symsearch.c
+++ b/scripts/mod/symsearch.c
@@ -240,3 +240,47 @@ Elf_Sym *symsearch_find_nearest(struct elf_info *elf, Elf_Addr addr,
return symsearch_find(elf, addr, secndx, allow_negative, min_distance,
symsearch_nearest_filter, elf);
}
+
+struct name_filter_data {
+ struct elf_info *elf;
+ const char *name;
+};
+
+static bool symsearch_name_filter(const Elf_Sym *sym1, const Elf_Sym *sym2,
+ void *_data)
+{
+ struct name_filter_data *data = _data;
+ const char *name;
+
+ /* Check the symbol name. */
+ name = sym_name(data->elf, sym1);
+ if (strcmp(name, data->name))
+ return false;
+
+ /* If sym2 is NULL, this is the first occurrence, always take it. */
+ if (!sym2)
+ return true;
+
+ /* Prefer lower address. */
+ return sym1->st_value < sym2->st_value;
+}
+
+/*
+ * Find the symbol which is in secndx and has the given name, and is located
+ * close enough to the given address.
+ * allow_negative: allow returning a symbol whose address is > addr.
+ * min_distance: ignore symbols which are further away than this.
+ * name: the name of the symbol to search for.
+ *
+ * Returns a pointer into the symbol table for success.
+ * Returns NULL if no legal symbol is found within the requested range.
+ */
+Elf_Sym *symsearch_find_with_name(struct elf_info *elf, Elf_Addr addr,
+ unsigned int secndx, bool allow_negative,
+ Elf_Addr min_distance, const char *name)
+{
+ struct name_filter_data data = { .elf = elf, .name = name };
+
+ return symsearch_find(elf, addr, secndx, allow_negative, min_distance,
+ symsearch_name_filter, &data);
+}
--
2.40.1
