RE: [PATCH 02/13] module: add a module_loaded helper

From: Christophe Leroy

Sent: 21 January 2021 10:00

Le 21/01/2021 à 08:49, Christoph Hellwig a écrit :

quoted

Add a helper that takes modules_mutex and uses find_module to check if a
given module is loaded.  This provides a better abstraction for the two
callers, and allows to unexport modules_mutex and find_module.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
  drivers/gpu/drm/drm_fb_helper.c |  7 +------
  include/linux/module.h          |  3 +++
  kernel/module.c                 | 14 ++++++++++++--
  kernel/trace/trace_kprobe.c     |  4 +---
  4 files changed, 17 insertions(+), 11 deletions(-)

quoted

diff --git a/include/linux/module.h b/include/linux/module.h
index 7a0bcb5b1ffccd..b4654f8a408134 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h

@@ -589,6 +589,9 @@ static inline bool within_module(unsigned long addr, const struct module *mod)
  /* Search for module by name: must hold module_mutex. */
  struct module *find_module(const char *name);

+/* Check if a module is loaded. */
+bool module_loaded(const char *name);

Maybe module_is_loaded() would be a better name.

I can't see the original patch.

What is the point of the function.
By the time it returns the information is stale - so mostly useless.

Surely you need to use try_module_get() instead?

	David

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