[PATCH v4 09/16] module: Group section index calculations together

From: Matthew Maurer
Date: Tue Sep 24 2024 - 17:23:13 EST


Group all the index detection together to make the parent function
easier to read.

Signed-off-by: Matthew Maurer <mmaurer@xxxxxxxxxx>
---
kernel/module/main.c | 68 +++++++++++++++++++++++++++++++++-----------
1 file changed, 51 insertions(+), 17 deletions(-)

diff --git a/kernel/module/main.c b/kernel/module/main.c
index 43140475aac0..e04a228c694a 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -2039,6 +2039,56 @@ static int elf_validity_cache_index_str(struct load_info *info)
return 0;
}

+/**
+ * elf_validity_cache_index() - Resolve, validate, cache section indices
+ * @info: Load info to read from and update.
+ * &load_info->sechdrs and &load_info->secstrings must be populated.
+ * @flags: Load flags, relevant to suppress version loading, see
+ * uapi/linux/module.h
+ *
+ * Populates &load_info->index, validating as it goes.
+ * See child functions for per-field validation:
+ *
+ * * elf_validity_cache_index_info()
+ * * elf_validity_cache_index_mod()
+ * * elf_validity_cache_index_sym()
+ * * elf_validity_cache_index_str()
+ *
+ * If versioning is not suppressed via flags, load the version index from
+ * a section called "__versions" with no validation.
+ *
+ * If CONFIG_SMP is enabled, load the percpu section by name with no
+ * validation.
+ *
+ * Return: 0 on success, negative error code if an index failed validation.
+ */
+static int elf_validity_cache_index(struct load_info *info, int flags)
+{
+ int err;
+
+ err = elf_validity_cache_index_info(info);
+ if (err < 0)
+ return err;
+ err = elf_validity_cache_index_mod(info);
+ if (err < 0)
+ return err;
+ err = elf_validity_cache_index_sym(info);
+ if (err < 0)
+ return err;
+ err = elf_validity_cache_index_str(info);
+ if (err < 0)
+ return err;
+
+ if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
+ info->index.vers = 0; /* Pretend no __versions section! */
+ else
+ info->index.vers = find_sec(info, "__versions");
+
+ info->index.pcpu = find_pcpusec(info);
+
+ return 0;
+}
+
/*
* Check userspace passed ELF module against our expectations, and cache
* useful variables for further processing as we go.
@@ -2069,16 +2119,7 @@ static int elf_validity_cache_copy(struct load_info *info, int flags)
err = elf_validity_cache_secstrings(info);
if (err < 0)
return err;
- err = elf_validity_cache_index_info(info);
- if (err < 0)
- return err;
- err = elf_validity_cache_index_mod(info);
- if (err < 0)
- return err;
- err = elf_validity_cache_index_sym(info);
- if (err < 0)
- return err;
- err = elf_validity_cache_index_str(info);
+ err = elf_validity_cache_index(info, flags);
if (err < 0)
return err;

@@ -2095,13 +2136,6 @@ static int elf_validity_cache_copy(struct load_info *info, int flags)
if (!info->name)
info->name = info->mod->name;

- if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
- info->index.vers = 0; /* Pretend no __versions section! */
- else
- info->index.vers = find_sec(info, "__versions");
-
- info->index.pcpu = find_pcpusec(info);
-
return 0;
}

--
2.46.1.824.gd892dcdcdd-goog