[PATCH v2 1/3] module: Modify module_flags() to accept show_state argument

Aaron Tomlin
2022-07-14T15:39:55Z

No functional change.

With this patch a given module's state information (i.e. 'mod->state')
can be omitted from the specified buffer. Please note that this is in
preparation to include the last unloaded module's taint flag(s),
if available.

Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
kernel/module/internal.h | 2 +-
kernel/module/main.c | 11 +++++++----
kernel/module/procfs.c | 2 +-
3 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index bc5507ab8450..60312f23c7d0 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -100,7 +100,7 @@ struct module *find_module_all(const char *name, size_t len, bool even_unformed)
int cmp_name(const void *name, const void *sym);
long module_get_offset(struct module *mod, unsigned int *size, Elf_Shdr *sechdr,
unsigned int section);
-char *module_flags(struct module *mod, char *buf);
+char *module_flags(struct module *mod, char *buf, bool show_state);
size_t module_flags_taint(unsigned long taints, char *buf);

static inline void module_assert_mutex_or_preempt(void)
diff --git a/kernel/module/main.c b/kernel/module/main.c
index fed58d30725d..a4d23b0ebbc0 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -2970,24 +2970,27 @@ static void cfi_cleanup(struct module *mod)
}

/* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
-char *module_flags(struct module *mod, char *buf)
+char *module_flags(struct module *mod, char *buf, bool show_state)
{
int bx = 0;

BUG_ON(mod->state == MODULE_STATE_UNFORMED);
+ if (!mod->taints && !show_state)
+ goto out;
if (mod->taints ||
mod->state == MODULE_STATE_GOING ||
mod->state == MODULE_STATE_COMING) {
buf[bx++] = '(';
bx += module_flags_taint(mod->taints, buf + bx);
/* Show a - for module-is-being-unloaded */
- if (mod->state == MODULE_STATE_GOING)
+ if (mod->state == MODULE_STATE_GOING && show_state)
buf[bx++] = '-';
/* Show a + for module-is-being-loaded */
- if (mod->state == MODULE_STATE_COMING)
+ if (mod->state == MODULE_STATE_COMING && show_state)
buf[bx++] = '+';
buf[bx++] = ')';
}
+out:
buf[bx] = '\0';

return buf;
@@ -3120,7 +3123,7 @@ void print_modules(void)
list_for_each_entry_rcu(mod, &modules, list) {
if (mod->state == MODULE_STATE_UNFORMED)
continue;
- pr_cont(" %s%s", mod->name, module_flags(mod, buf));
+ pr_cont(" %s%s", mod->name, module_flags(mod, buf, true));
}

print_unloaded_tainted_modules();
diff --git a/kernel/module/procfs.c b/kernel/module/procfs.c
index 9a8f4f0f6329..cf5b9f1e6ec4 100644
--- a/kernel/module/procfs.c
+++ b/kernel/module/procfs.c
@@ -91,7 +91,7 @@ static int m_show(struct seq_file *m, void *p)

/* Taints info */
if (mod->taints)
- seq_printf(m, " %s", module_flags(mod, buf));
+ seq_printf(m, " %s", module_flags(mod, buf, true));

seq_puts(m, "\n");
return 0;
--
2.34.3