linux_dsm_epyc7002/arch/arc
Vineet Gupta 3925a16ae9 ARC: mm: don't loose PTE_SPECIAL in pte_modify()
LTP madvise05 was generating mm splat

| [ARCLinux]# /sd/ltp/testcases/bin/madvise05
| BUG: Bad page map in process madvise05  pte:80e08211 pmd:9f7d4000
| page:9fdcfc90 count:1 mapcount:-1 mapping:  (null) index:0x0 flags: 0x404(referenced|reserved)
| page dumped because: bad pte
| addr:200b8000 vm_flags:00000070 anon_vma:  (null) mapping:  (null) index:1005c
| file:  (null) fault:  (null) mmap:  (null) readpage:  (null)
| CPU: 2 PID: 6707 Comm: madvise05

And for newer kernels, the system was rendered unusable afterwards.

The problem was mprotect->pte_modify() clearing PTE_SPECIAL (which is
set to identify the special zero page wired to the pte).
When pte was finally unmapped, special casing for zero page was not
done, and instead it was treated as a "normal" page, tripping on the
map counts etc.

This fixes ARC STAR 9001053308

Cc: <stable@vger.kernel.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-07-28 12:38:17 -07:00
..
boot arc: Get rid of root core-frequency property 2016-05-30 10:07:32 +05:30
configs ARC: [plat-eznps] Add eznps board defconfig and dts 2016-05-09 09:32:32 +05:30
include ARC: mm: don't loose PTE_SPECIAL in pte_modify() 2016-07-28 12:38:17 -07:00
kernel ARC: fix linux-next build breakage 2016-07-13 16:48:20 -07:00
lib ARCv2: lib: memcpy: use local symbols 2015-11-03 17:33:00 +05:30
mm ARC: dma: fix address translation in arc_dma_free 2016-07-20 09:54:22 -07:00
oprofile ARC: OProfile support 2013-02-15 23:16:00 +05:30
plat-axs10x ARC updates for 4.7-rc1 2016-05-19 09:46:18 -07:00
plat-eznps ARC: [plat-eznps] Use dedicated identity auxiliary register. 2016-05-09 09:32:33 +05:30
plat-sim ARC: remove extraneous header include 2015-11-14 13:11:38 +05:30
plat-tb10x arc: select GPIOLIB directly 2016-04-26 14:07:59 +02:00
Kbuild ARC: Build system: Makefiles, Kconfig, Linker script 2013-02-11 20:00:25 +05:30
Kconfig Revert "ARCv2: spinlock/rwlock/atomics: Delayed retry of failed SCOND with exponential backoff" 2016-06-02 10:59:23 +05:30
Kconfig.debug ARC: With earlycon in use, retire EARLY_PRINTK 2015-05-11 11:20:21 +05:30
Makefile ARC: unwind: ensure that .debug_frame is generated (vs. .eh_frame) 2016-06-28 09:42:28 +05:30