On Fri, 30 Oct, 2020, 1:32 PM Greg KH, gregkh@linuxfoundation.org wrote:
On Fri, Oct 30, 2020 at 01:27:16PM +0530, Deepak R Varma wrote:
On Fri, Oct 30, 2020 at 08:11:20AM +0100, Greg KH wrote:
On Fri, Oct 30, 2020 at 08:52:45AM +0530, Deepak R Varma wrote:
Using DEFINE_DEBUGFS_ATTRIBUTE macro with
debugfs_create_file_unsafe()
function in place of the debugfs_create_file() function will make the file operation struct "reset" aware of the file's lifetime.
Additional
details here:
https://lists.archive.carbon60.com/linux/kernel/2369498
Issue reported by Coccinelle script: scripts/coccinelle/api/debugfs/debugfs_simple_attr.cocci
Signed-off-by: Deepak R Varma mh12gx2825@gmail.com
Please Note: This is a Outreachy project task patch.
drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 20
++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
index 2d125b8b15ee..f076b1ba7319 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c @@ -1551,29 +1551,29 @@ static int amdgpu_debugfs_sclk_set(void
*data, u64 val)
return 0; }
-DEFINE_SIMPLE_ATTRIBUTE(fops_ib_preempt, NULL,
amdgpu_debugfs_ib_preempt, "%llu\n");+DEFINE_DEBUGFS_ATTRIBUTE(fops_ib_preempt, NULL,
amdgpu_debugfs_ib_preempt, "%llu\n");Are you sure this is ok? Do these devices need this additional "protection"? Do they have the problem that these macros were written for?
Same for the other patches you just submitted here, I think you need to somehow "prove" that these changes are necessary, checkpatch isn't able to determine this all the time.
Hi Greg, Based on my understanding, the current function debugfs_create_file() adds an overhead of lifetime managing proxy for such fop structs. This should be applicable to these set of drivers as well. Hence I think this change will be useful.
Why do these drivers need these changes? Are these files dynamically removed from the system at random times?
There is a reason we didn't just do a global search/replace for this in the kernel when the new functions were added, so I don't know why checkpatch is now saying it must be done.
Hi,
Sorry to jump in on the thread this way, but what exactly does a 'lifetime managing proxy' for file operations mean? I am trying to understand how DEFINE_DEBUGFS_ATTRIBUTE changes things wrt debug_ fs file operations but can't find many resources. :(
Please let me know if I should be asking this in a different mailing list/irc instead.
The change seems to be suggested by a coccinelle script.
Regards, Sumera
thanks,
greg k-h
-- You received this message because you are subscribed to the Google Groups "outreachy-kernel" group. To unsubscribe from this group and stop receiving emails from it, send an email to outreachy-kernel+unsubscribe@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/outreachy-kernel/20201030080316.GA1612206%... .