| commit | ce19c2986d069294f5409430746069102603aa82 | |
| author | Milton Miller <miltonm@bga.com> | |
| Tue, 10 May 2011 19:28:33 +0000 (10 19:28 +0000) | ||
| committer | Greg Kroah-Hartman <gregkh@suse.de> | |
| Fri, 3 Jun 2011 01:33:37 +0000 (3 10:33 +0900) | ||
| tree | a4e275d20fee2c593460b503a06d1f49756656c5 | treesnapshot (tar.gz zip) |
| parent | 2752ce97f6a85284c1859ca932c654f4deceeba6 | commitdiff |
powerpc/kexec: Fix memory corruption from unallocated slaves
commit 3d2cea732d68aa270c360f55d8669820ebce188a upstream.
Commit 1fc711f7ffb01089efc58042cfdbac8573d1b59a (powerpc/kexec: Fix race
in kexec shutdown) moved the write to signal the cpu had exited the kernel
from before the transition to real mode in kexec_smp_wait to kexec_wait.
Unfornately it missed that kexec_wait is used both by cpus leaving the
kernel and by secondary slave cpus that were not allocated a paca for
what ever reason -- they could be beyond nr_cpus or not described in
the current device tree for whatever reason (for example, kexec-load
was not refreshed after a cpu hotplug operation). Cpus coming through
that path they will write to paca[NR_CPUS] which is beyond the space
allocated for the paca data and overwrite memory not allocated to pacas
but very likely still real mode accessable).
Move the write back to kexec_smp_wait, which is used only by cpus that
found their paca, but after the transition to real mode.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 3d2cea732d68aa270c360f55d8669820ebce188a upstream.
Commit 1fc711f7ffb01089efc58042cfdbac8573d1b59a (powerpc/kexec: Fix race
in kexec shutdown) moved the write to signal the cpu had exited the kernel
from before the transition to real mode in kexec_smp_wait to kexec_wait.
Unfornately it missed that kexec_wait is used both by cpus leaving the
kernel and by secondary slave cpus that were not allocated a paca for
what ever reason -- they could be beyond nr_cpus or not described in
the current device tree for whatever reason (for example, kexec-load
was not refreshed after a cpu hotplug operation). Cpus coming through
that path they will write to paca[NR_CPUS] which is beyond the space
allocated for the paca data and overwrite memory not allocated to pacas
but very likely still real mode accessable).
Move the write back to kexec_smp_wait, which is used only by cpus that
found their paca, but after the transition to real mode.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| arch/powerpc/kernel/misc_64.S | diffblobblamehistory |