diff options
| author | John Hubbard <jhubbard@nvidia.com> | 2014-04-07 15:37:59 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-04-07 16:35:59 -0700 |
| commit | ed12d845b5f528cc0846023862b9c448a36122ec (patch) | |
| tree | 37e1fde944c5c1d62ed780abd32ac52846672365 /mm | |
| parent | 834a964a098e7726fc296d7cd8f65ed3eeedd412 (diff) | |
mm/page_alloc.c: change mm debug routines back to EXPORT_SYMBOL
A new dump_page() routine was recently added, and marked
EXPORT_SYMBOL_GPL. dump_page() was also added to the VM_BUG_ON_PAGE()
macro, and so the end result is that non-GPL code can no longer call
get_page() and a few other routines.
This only happens if the kernel was compiled with CONFIG_DEBUG_VM.
Change dump_page() to be EXPORT_SYMBOL.
Longer explanation:
Prior to commit 309381feaee5 ("mm: dump page when hitting a VM_BUG_ON
using VM_BUG_ON_PAGE") , it was possible to build MIT-licensed (non-GPL)
drivers on Fedora. Fedora is semi-unique, in that it sets
CONFIG_VM_DEBUG.
Because Fedora sets CONFIG_VM_DEBUG, they end up pulling in dump_page(),
via VM_BUG_ON_PAGE, via get_page(). As one of the authors of NVIDIA's
new, open source, "UVM-Lite" kernel module, I originally choose to use
the kernel's get_page() routine from within nvidia_uvm_page_cache.c,
because get_page() has always seemed to be very clearly intended for use
by non-GPL, driver code.
So I'm hoping that making get_page() widely accessible again will not be
too controversial. We did check with Fedora first, and they responded
(https://bugzilla.redhat.com/show_bug.cgi?id=1074710#c3) that we should
try to get upstream changed, before asking Fedora to change. Their
reasoning seems beneficial to Linux: leaving CONFIG_DEBUG_VM set allows
Fedora to help catch mm bugs.
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Josh Boyer <jwboyer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/page_alloc.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 48427a7cfb45..5dba2933c9c0 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -6568,4 +6568,4 @@ void dump_page(struct page *page, const char *reason) { dump_page_badflags(page, reason, 0); } -EXPORT_SYMBOL_GPL(dump_page); +EXPORT_SYMBOL(dump_page); |