From f5678e7f2ac31c270334b936352f0ef2fe7dd2b3 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 10 Jun 2020 18:42:06 -0700 Subject: kernel: better document the use_mm/unuse_mm API contract Switch the function documentation to kerneldoc comments, and add WARN_ON_ONCE asserts that the calling thread is a kernel thread and does not have ->mm set (or has ->mm set in the case of unuse_mm). Also give the functions a kthread_ prefix to better document the use case. [hch@lst.de: fix a comment typo, cover the newly merged use_mm/unuse_mm caller in vfio] Link: http://lkml.kernel.org/r/20200416053158.586887-3-hch@lst.de [sfr@canb.auug.org.au: powerpc/vas: fix up for {un}use_mm() rename] Link: http://lkml.kernel.org/r/20200422163935.5aa93ba5@canb.auug.org.au Signed-off-by: Christoph Hellwig Signed-off-by: Stephen Rothwell Signed-off-by: Andrew Morton Tested-by: Jens Axboe Reviewed-by: Jens Axboe Acked-by: Felix Kuehling Acked-by: Greg Kroah-Hartman [usb] Acked-by: Haren Myneni Cc: Alex Deucher Cc: Al Viro Cc: Felipe Balbi Cc: Jason Wang Cc: "Michael S. Tsirkin" Cc: Zhenyu Wang Cc: Zhi Wang Link: http://lkml.kernel.org/r/20200404094101.672954-6-hch@lst.de Signed-off-by: Linus Torvalds --- arch/powerpc/platforms/powernv/vas-fault.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/powerpc') diff --git a/arch/powerpc/platforms/powernv/vas-fault.c b/arch/powerpc/platforms/powernv/vas-fault.c index 25db70be4c9c..266a6ca5e15e 100644 --- a/arch/powerpc/platforms/powernv/vas-fault.c +++ b/arch/powerpc/platforms/powernv/vas-fault.c @@ -127,7 +127,7 @@ static void update_csb(struct vas_window *window, return; } - use_mm(window->mm); + kthread_use_mm(window->mm); rc = copy_to_user(csb_addr, &csb, sizeof(csb)); /* * User space polls on csb.flags (first byte). So add barrier @@ -139,7 +139,7 @@ static void update_csb(struct vas_window *window, smp_mb(); rc = copy_to_user(csb_addr, &csb, sizeof(u8)); } - unuse_mm(window->mm); + kthread_unuse_mm(window->mm); put_task_struct(tsk); /* Success */ -- cgit v1.2.3