linux/arch
Maksim Rayskiy 5c20019713 MIPS: ASID conflict after CPU hotplug
I am running SMP Linux 2.6.37-rc1 on BMIPS5000 (single core dual thread)
and observe some abnormalities when doing system suspend/resume which I
narrowed down to cpu hotplugging. The suspend brings the second thread
processor down and then restarts it, after which I see memory corruption
in userspace. I started digging and found out that problem occurs because
while doing execve() the child process is getting the same ASID as the
parent, which obviously corrupts parent's address space.

Further digging showed that activate_mm() calls get_new_mmu_context() to
get a new ASID, but at this time ASID field in entryHi is 1, and
asid_cache(cpu) is 0x100 (it was just reset to ASID_FIRST_VERSION when
the secondary TP was booting).

So, get_new_mmu_context() increments the asid_cache(cpu) value to
0x101, and thus puts 0x01 into entryHi. The result - ASID field does
not get changed as it was supposed to.

My solution is very simple - do not reset asid_cache(cpu) on TP warm
restart.

Patchwork: https://patchwork.linux-mips.org/patch/1797/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2011-11-10 17:59:45 +00:00
..
alpha Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
arm Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap 2011-11-07 16:14:26 -08:00
avr32 Merge git://git.infradead.org/mtd-2.6 2011-11-07 09:11:16 -08:00
blackfin blackfin: add module.h to files implicitly expecting to use it. 2011-10-31 19:31:02 -04:00
cris Merge git://git.infradead.org/mtd-2.6 2011-11-07 09:11:16 -08:00
frv kgdb: follow rename pack_hex_byte() to hex_byte_pack() 2011-10-31 17:30:56 -07:00
h8300 Merge branch 'gpio/next' of git://git.secretlab.ca/git/linux-2.6 2011-10-29 07:27:45 -07:00
hexagon Hexagon: Add basic stacktrace functionality for Hexagon architecture. 2011-11-01 07:34:21 -07:00
ia64 Merge branch 'upstream/xen-settime' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen 2011-11-06 20:15:05 -08:00
m32r Merge branch 'trivial' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2011-11-06 18:54:53 -08:00
m68k Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
microblaze Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
mips MIPS: ASID conflict after CPU hotplug 2011-11-10 17:59:45 +00:00
mn10300 kgdb: follow rename pack_hex_byte() to hex_byte_pack() 2011-10-31 17:30:56 -07:00
openrisc Merge branch 'trivial' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2011-11-06 18:54:53 -08:00
parisc parisc: Add export.h to files needing EXPORT_SYMBOL/THIS_MODULE 2011-10-31 19:31:00 -04:00
powerpc Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
s390 Merge branch 'upstream/jump-label-noearly' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen 2011-11-06 20:20:46 -08:00
score score: drop unused Kconfig symbols 2011-10-31 23:39:51 +01:00
sh Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 2011-11-07 10:13:52 -08:00
sparc Merge branch 'upstream/jump-label-noearly' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen 2011-11-06 20:20:46 -08:00
tile Merge branch 'for-linus' of git://github.com/cmetcalf-tilera/linux-tile 2011-11-04 12:33:34 -07:00
um Merge branch 'for-linus' of git://github.com/richardweinberger/linux 2011-11-02 09:45:39 -07:00
unicore32 unicore32: EXPORT_SYMBOL needs export.h 2011-10-31 19:31:06 -04:00
x86 Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 2011-11-07 10:13:52 -08:00
xtensa Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2011-10-26 17:15:03 +02:00
.gitignore
Kconfig Add Kconfig option ARCH_HAVE_NMI_SAFE_CMPXCHG 2011-08-03 11:12:37 -04:00