| Message ID | 1455057734-6162-1-git-send-email-kamal@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c index bb0ea94..491acbb 100644 --- a/arch/arm64/mm/pageattr.c +++ b/arch/arm64/mm/pageattr.c @@ -54,6 +54,9 @@ static int change_memory_common(unsigned long addr, int numpages, if (!is_module_address(start) || !is_module_address(end - 1)) return -EINVAL; + if (!numpages) + return 0; + data.set_mask = set_mask; data.clear_mask = clear_mask;
This is a note to let you know that I have just added a patch titled arm64: mm: avoid calling apply_to_page_range on empty range to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue This patch is scheduled to be released in version 3.19.8-ckt15. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.19.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ---8<------------------------------------------------------------ From 844fc3628781ddd6faf623f8e7874cc1f5db55b3 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Mika=20Penttil=C3=A4?= <mika.penttila@nextfour.com> Date: Tue, 26 Jan 2016 15:47:25 +0000 Subject: arm64: mm: avoid calling apply_to_page_range on empty range MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit 57adec866c0440976c96a4b8f5b59fb411b1cacb upstream. Calling apply_to_page_range with an empty range results in a BUG_ON from the core code. This can be triggered by trying to load the st_drv module with CONFIG_DEBUG_SET_MODULE_RONX enabled: kernel BUG at mm/memory.c:1874! Internal error: Oops - BUG: 0 [#1] PREEMPT SMP Modules linked in: CPU: 3 PID: 1764 Comm: insmod Not tainted 4.5.0-rc1+ #2 Hardware name: ARM Juno development board (r0) (DT) task: ffffffc9763b8000 ti: ffffffc975af8000 task.ti: ffffffc975af8000 PC is at apply_to_page_range+0x2cc/0x2d0 LR is at change_memory_common+0x80/0x108 This patch fixes the issue by making change_memory_common (called by the set_memory_* functions) a NOP when numpages == 0, therefore avoiding the erroneous call to apply_to_page_range and bringing us into line with x86 and s390. Reviewed-by: Laura Abbott <labbott@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Mika Penttilä <mika.penttila@nextfour.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- arch/arm64/mm/pageattr.c | 3 +++ 1 file changed, 3 insertions(+) -- 1.9.1