3.19.8-ckt15 -stable review patch. If anyone has any objections, please let me know.
---8<------------------------------------------------------------ From: =?UTF-8?q?Mika=20Penttil=C3=A4?= <[email protected]> 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 <[email protected]> Acked-by: David Rientjes <[email protected]> Signed-off-by: Mika Penttilä <[email protected]> Signed-off-by: Will Deacon <[email protected]> Signed-off-by: Kamal Mostafa <[email protected]> --- arch/arm64/mm/pageattr.c | 3 +++ 1 file changed, 3 insertions(+) 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; -- 1.9.1
