Revision f43c27188a49111b58e9611afa2f0365b0b55625 authored by Lorenzo Pieralisi on 19 December 2014, 17:03:47 UTC, committed by Catalin Marinas on 23 December 2014, 16:38:50 UTC
On arm64 the TTBR0_EL1 register is set to either the reserved TTBR0 page tables on boot or to the active_mm mappings belonging to user space processes, it must never be set to swapper_pg_dir page tables mappings. When a CPU is booted its active_mm is set to init_mm even though its TTBR0_EL1 points at the reserved TTBR0 page mappings. This implies that when __cpu_suspend is triggered the active_mm can point at init_mm even if the current TTBR0_EL1 register contains the reserved TTBR0_EL1 mappings. Therefore, the mm save and restore executed in __cpu_suspend might turn out to be erroneous in that, if the current->active_mm corresponds to init_mm, on resume from low power it ends up restoring in the TTBR0_EL1 the init_mm mappings that are global and can cause speculation of TLB entries which end up being propagated to user space. This patch fixes the issue by checking the active_mm pointer before restoring the TTBR0 mappings. If the current active_mm == &init_mm, the code sets the TTBR0_EL1 to the reserved TTBR0 mapping instead of switching back to the active_mm, which is the expected behaviour corresponding to the TTBR0_EL1 settings when __cpu_suspend was entered. Fixes: 95322526ef62 ("arm64: kernel: cpu_{suspend/resume} implementation") Cc: <stable@vger.kernel.org> # 3.14+: 18ab7db Cc: <stable@vger.kernel.org> # 3.14+: 714f599 Cc: <stable@vger.kernel.org> # 3.14+: c3684fb Cc: <stable@vger.kernel.org> # 3.14+ Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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File | Mode | Size |
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partitions | ||
Kconfig | -rw-r--r-- | 3.7 KB |
Kconfig.iosched | -rw-r--r-- | 1.6 KB |
Makefile | -rw-r--r-- | 923 bytes |
bio-integrity.c | -rw-r--r-- | 14.0 KB |
bio.c | -rw-r--r-- | 51.2 KB |
blk-cgroup.c | -rw-r--r-- | 29.6 KB |
blk-cgroup.h | -rw-r--r-- | 16.6 KB |
blk-core.c | -rw-r--r-- | 89.3 KB |
blk-exec.c | -rw-r--r-- | 3.5 KB |
blk-flush.c | -rw-r--r-- | 14.8 KB |
blk-integrity.c | -rw-r--r-- | 12.4 KB |
blk-ioc.c | -rw-r--r-- | 10.2 KB |
blk-iopoll.c | -rw-r--r-- | 5.8 KB |
blk-lib.c | -rw-r--r-- | 7.3 KB |
blk-map.c | -rw-r--r-- | 8.2 KB |
blk-merge.c | -rw-r--r-- | 14.9 KB |
blk-mq-cpu.c | -rw-r--r-- | 1.6 KB |
blk-mq-cpumap.c | -rw-r--r-- | 2.5 KB |
blk-mq-sysfs.c | -rw-r--r-- | 10.6 KB |
blk-mq-tag.c | -rw-r--r-- | 14.6 KB |
blk-mq-tag.h | -rw-r--r-- | 2.0 KB |
blk-mq.c | -rw-r--r-- | 49.5 KB |
blk-mq.h | -rw-r--r-- | 3.2 KB |
blk-settings.c | -rw-r--r-- | 27.2 KB |
blk-softirq.c | -rw-r--r-- | 4.4 KB |
blk-sysfs.c | -rw-r--r-- | 15.5 KB |
blk-tag.c | -rw-r--r-- | 9.4 KB |
blk-throttle.c | -rw-r--r-- | 45.8 KB |
blk-timeout.c | -rw-r--r-- | 5.7 KB |
blk.h | -rw-r--r-- | 8.6 KB |
bounce.c | -rw-r--r-- | 6.5 KB |
bsg-lib.c | -rw-r--r-- | 6.0 KB |
bsg.c | -rw-r--r-- | 23.6 KB |
cfq-iosched.c | -rw-r--r-- | 120.1 KB |
cmdline-parser.c | -rw-r--r-- | 4.9 KB |
compat_ioctl.c | -rw-r--r-- | 20.8 KB |
deadline-iosched.c | -rw-r--r-- | 11.3 KB |
elevator.c | -rw-r--r-- | 23.7 KB |
genhd.c | -rw-r--r-- | 44.3 KB |
ioctl.c | -rw-r--r-- | 10.7 KB |
ioprio.c | -rw-r--r-- | 5.0 KB |
noop-iosched.c | -rw-r--r-- | 2.7 KB |
partition-generic.c | -rw-r--r-- | 14.0 KB |
scsi_ioctl.c | -rw-r--r-- | 19.6 KB |
t10-pi.c | -rw-r--r-- | 5.1 KB |
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