kernel/linux.git/arch/unicore32/mm, branch linux-4.4.y

mm/fault, arch: Use pagefault_disable() to check for disabled pagefaults in the handler

2015-05-19T06:39:15+00:00

Introduce faulthandler_disabled() and use it to check for irq context and disabled pagefaults (via pagefault_disable()) in the pagefault handlers. Please note that we keep the in_atomic() checks in place - to detect whether in irq context (in which case preemption is always properly disabled). In contrast, preempt_disable() should never be used to disable pagefaults. With !CONFIG_PREEMPT_COUNT, preempt_disable() doesn't modify the preempt counter, and therefore the result of in_atomic() differs. We validate that condition by using might_fault() checks when calling might_sleep(). Therefore, add a comment to faulthandler_disabled(), describing why this is needed. faulthandler_disabled() and pagefault_disable() are defined in linux/uaccess.h, so let's properly add that include to all relevant files. This patch is based on a patch from Thomas Gleixner. Reviewed-and-tested-by: Thomas Gleixner Signed-off-by: David Hildenbrand Signed-off-by: Peter Zijlstra (Intel) Cc: David.Laight@ACULAB.COM Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: airlied@linux.ie Cc: akpm@linux-foundation.org Cc: benh@kernel.crashing.org Cc: bigeasy@linutronix.de Cc: borntraeger@de.ibm.com Cc: daniel.vetter@intel.com Cc: heiko.carstens@de.ibm.com Cc: herbert@gondor.apana.org.au Cc: hocko@suse.cz Cc: hughd@google.com Cc: mst@redhat.com Cc: paulus@samba.org Cc: ralf@linux-mips.org Cc: schwidefsky@de.ibm.com Cc: yang.shi@windriver.com Link: http://lkml.kernel.org/r/1431359540-32227-7-git-send-email-dahi@linux.vnet.ibm.com Signed-off-by: Ingo Molnar

mm: fix false-positive warning on exit due mm_nr_pmds(mm)

2015-02-12T01:06:04+00:00

The problem is that we check nr_ptes/nr_pmds in exit_mmap() which happens *before* pgd_free(). And if an arch does pte/pmd allocation in pgd_alloc() and frees them in pgd_free() we see offset in counters by the time of the checks. We tried to workaround this by offsetting expected counter value according to FIRST_USER_ADDRESS for both nr_pte and nr_pmd in exit_mmap(). But it doesn't work in some cases: 1. ARM with LPAE enabled also has non-zero USER_PGTABLES_CEILING, but upper addresses occupied with huge pmd entries, so the trick with offsetting expected counter value will get really ugly: we will have to apply it nr_pmds, but not nr_ptes. 2. Metag has non-zero FIRST_USER_ADDRESS, but doesn't do allocation pte/pmd page tables allocation in pgd_alloc(), just setup a pgd entry which is allocated at boot and shared accross all processes. The proposal is to move the check to check_mm() which happens *after* pgd_free() and do proper accounting during pgd_alloc() and pgd_free() which would bring counters to zero if nothing leaked. Signed-off-by: Kirill A. Shutemov Reported-by: Tyler Baker Tested-by: Tyler Baker Tested-by: Nishanth Menon Cc: Russell King Cc: James Hogan Cc: Guan Xuetao Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

arch: unicore32: ksyms: export '__cpuc_coherent_kern_range' to avoid compiling failure

2014-06-20T00:22:41+00:00

flush_icache_range() is '__cpuc_coherent_kern_range' under unicore32, and lkdtm.ko needs it. At present, '__cpuc_coherent_kern_range' is still used by unicore32, so export it to avoid compiling failure. The related error (with allmodconfig under unicore32): ERROR: "__cpuc_coherent_kern_range" [drivers/misc/lkdtm.ko] undefined! Signed-off-by: Chen Gang Acked-by: Xuetao Guan Signed-off-by: Xuetao Guan

arch/unicore32/mm/alignment.c: include "asm/pgtable.h" to avoid compiling error

2014-06-20T00:22:38+00:00

Need include "asm/pgtable.h" to include "asm-generic/pgtable-nopmd.h", so can let 'pmd_t' defined. The related error with allmodconfig: CC arch/unicore32/mm/alignment.o In file included from arch/unicore32/mm/alignment.c:24: arch/unicore32/include/asm/tlbflush.h:135: error: expected .). before .*. token arch/unicore32/include/asm/tlbflush.h:154: error: expected .). before .*. token In file included from arch/unicore32/mm/alignment.c:27: arch/unicore32/mm/mm.h:15: error: expected .=., .,., .;., .sm. or ._attribute__. before .*. token arch/unicore32/mm/mm.h:20: error: expected .=., .,., .;., .sm. or ._attribute__. before .*. token arch/unicore32/mm/mm.h:25: error: expected .=., .,., .;., .sm. or ._attribute__. before .*. token make[1]: *** [arch/unicore32/mm/alignment.o] Error 1 make: *** [arch/unicore32/mm] Error 2 Signed-off-by: Chen Gang Acked-by: Xuetao Guan Signed-off-by: Xuetao Guan

arch/unicore32/mm/ioremap.c: return NULL on invalid pfn

2014-06-04T23:53:53+00:00

__uc32_ioremap_pfn_caller() should return NULL when the pfn is found to be invalid. From a recommendation by Guan Xuetao. Cc: Guan Xuetao Cc: Fabian Frederick Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

arch/unicore32/mm/ioremap.c: convert printk/warn_on to warn()

2014-06-04T23:53:53+00:00

Coalesce formats. [akpm@linux-foundation.org: undo crazy long line] Signed-off-by: Fabian Frederick Cc: Guan Xuetao Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm, show_mem: remove SHOW_MEM_FILTER_PAGE_COUNT

2014-01-22T00:19:44+00:00

Commit 4b59e6c47309 ("mm, show_mem: suppress page counts in non-blockable contexts") introduced SHOW_MEM_FILTER_PAGE_COUNT to suppress PFN walks on large memory machines. Commit c78e93630d15 ("mm: do not walk all of system memory during show_mem") avoided a PFN walk in the generic show_mem helper which removes the requirement for SHOW_MEM_FILTER_PAGE_COUNT in that case. This patch removes PFN walkers from the arch-specific implementations that report on a per-node or per-zone granularity. ARM and unicore32 still do a PFN walk as they report memory usage on each bank which is a much finer granularity where the debugging information may still be of use. As the remaining arches doing PFN walks have relatively small amounts of memory, this patch simply removes SHOW_MEM_FILTER_PAGE_COUNT. [akpm@linux-foundation.org: fix parisc] Signed-off-by: Mel Gorman Acked-by: David Rientjes Cc: Tony Luck Cc: Russell King Cc: James Bottomley Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

arch: mm: pass userspace fault flag to generic fault handler

2013-09-12T22:38:01+00:00

Unlike global OOM handling, memory cgroup code will invoke the OOM killer in any OOM situation because it has no way of telling faults occuring in kernel context - which could be handled more gracefully - from user-triggered faults. Pass a flag that identifies faults originating in user space from the architecture-specific fault handlers to generic code so that memcg OOM handling can be improved. Signed-off-by: Johannes Weiner Reviewed-by: Michal Hocko Cc: David Rientjes Cc: KAMEZAWA Hiroyuki Cc: azurIt Cc: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

arch: mm: do not invoke OOM killer on kernel fault OOM

2013-09-12T22:38:01+00:00

Kernel faults are expected to handle OOM conditions gracefully (gup, uaccess etc.), so they should never invoke the OOM killer. Reserve this for faults triggered in user context when it is the only option. Most architectures already do this, fix up the remaining few. Signed-off-by: Johannes Weiner Reviewed-by: Michal Hocko Acked-by: KOSAKI Motohiro Cc: David Rientjes Cc: KAMEZAWA Hiroyuki Cc: azurIt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

reboot: unicore32: prepare reboot_mode for moving to generic kernel code

2013-07-09T17:33:29+00:00

Prepare for the moving the parsing of reboot= to the generic kernel code by making reboot_mode into a more generic form. Signed-off-by: Robin Holt Cc: Guan Xuetao Cc: Russ Anderson Cc: Robin Holt Cc: Russell King Cc: H. Peter Anvin Acked-by: Guan Xuetao Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds