linux-stable/arch/parisc/kernel
James Bottomley 618febd678 [PARISC] Fix the alloc_slabmgmt panic
Fix the alloc_slabmgmt panic

Hopefully this should also fix a lot of other intermittent kernel bugs.

The problem has been around since 2.6.9-rc2-pa6 when we allowed
floating point registers to be used in kernel code.  The essence of
the problem is that gcc prefers to use floating point for integer
divides and multiples.  Further, it can rely on the values in the no
clobber fp regs being correct across a function call.  Unfortunately,
our task switch function only saves the integer no clobber registers,
not the fp ones, so if gcc makes a function call to any function in
the kernel which could sleep, the values it is relying on in any no
clobber floating point register may be lost.  In the case of
alloc_slabmgmt, the value of the page offset is being stored in %fr12
across a call to kmem_getpages(), which sleeps if no pages are
available.  Thus, the offset can be trashed and the slab code can end
up with a completely bogus address leading to corruption.

Kudos to Randolph who came up with the program to trip this problem at
will and thus allowed it to be tracked and fixed.

Signed-off-by: James Bottomley <jejb@parisc-linux.org>

Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2005-10-21 22:53:26 -04:00
..
asm-offsets.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
binfmt_elf32.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
cache.c [PARISC] Fix parisc_setup_cache_timing to choose a better flush threshold 2005-10-21 22:44:14 -04:00
drivers.c [PARISC] Convert parisc_device tree to use struct device klists 2005-10-21 22:33:38 -04:00
entry.S [PARISC] Fix the alloc_slabmgmt panic 2005-10-21 22:53:26 -04:00
firmware.c [PARISC] Document history of PDC_NARROW as it is now obsolete 2005-10-21 22:51:40 -04:00
hardware.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
head.S [PARISC] Replace uses of __LP64__ with CONFIG_64BIT 2005-10-21 22:46:48 -04:00
hpmc.S Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
init_task.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
inventory.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
ioctl32.c [PARISC] kfree cleanups to ioctl32.c 2005-10-21 22:51:23 -04:00
irq.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
Makefile Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
module.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
pa7300lc.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
pacache.S [PARISC] Replace uses of __LP64__ with CONFIG_64BIT 2005-10-21 22:46:48 -04:00
parisc_ksyms.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
pci-dma.c [PARISC] Cleanup whitespace and handle proc_mkdir() failures in pci-dma.c 2005-10-21 22:50:48 -04:00
pci.c [PARISC] More informative error message in pcibios_link_hba_resources 2005-10-21 22:50:33 -04:00
pdc_chassis.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
pdc_cons.c [PARISC] Update pdc console from parisc tree 2005-10-21 22:50:06 -04:00
perf.c [PARISC] Convert parisc_device to use struct resource for hpa 2005-10-21 22:36:40 -04:00
perf_asm.S Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
perf_images.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
process.c [PARISC] Implement 5 argument clone. 2005-10-21 22:53:04 -04:00
processor.c [PARISC] Convert parisc_device to use struct resource for hpa 2005-10-21 22:36:40 -04:00
ptrace.c kbuild: m68k,parisc,ppc,ppc64,s390,xtensa use generic asm-offsets.h support 2005-09-09 20:57:26 +02:00
real2.S [PARISC] Replace uses of __LP64__ with CONFIG_64BIT 2005-10-21 22:46:48 -04:00
semaphore.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
setup.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
signal.c [PARISC] Prevent signal loops if we have a problem setting up a frame 2005-10-21 22:49:47 -04:00
signal32.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
signal32.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
smp.c [PARISC] Replace uses of __LP64__ with CONFIG_64BIT 2005-10-21 22:46:48 -04:00
sys32.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sys_parisc.c [PATCH] consolidate sys_shmat 2005-05-01 08:59:12 -07:00
sys_parisc32.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
syscall.S [PARISC] Replace uses of __LP64__ with CONFIG_64BIT 2005-10-21 22:46:48 -04:00
syscall_table.S [PARISC] Replace uses of __LP64__ with CONFIG_64BIT 2005-10-21 22:46:48 -04:00
time.c [PARISC] Use work queue in LED/LCD driver instead of tasklet. 2005-10-21 22:46:18 -04:00
topology.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
traps.c [PARISC] Add printing of fpregs state to stack dump 2005-10-21 22:49:25 -04:00
unaligned.c [PARISC] Add ability for prctl to change unaligned trap behaviour 2005-10-21 22:43:15 -04:00
unwind.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
vmlinux.lds.S Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00