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author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2013-02-28 16:28:41 +0100 |
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committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2013-03-05 10:21:35 +0100 |
commit | 6551fbdfd8b85d1ab5822ac98abb4fb449bcfae0 (patch) | |
tree | 7e44d437d9332332ba7dff50091a6c4e44efc644 /arch/s390/Kconfig.debug | |
parent | 6dbe51c251a327e012439c4772097a13df43c5b8 (diff) |
s390: critical section cleanup vs. machine checks
The current machine check code uses the registers stored by the machine
in the lowcore at __LC_GPREGS_SAVE_AREA as the registers of the interrupted
context. The registers 0-7 of a user process can get clobbered if a machine
checks interrupts the execution of a critical section in entry[64].S.
The reason is that the critical section cleanup code may need to modify
the PSW and the registers for the previous context to get to the end of a
critical section. If registers 0-7 have to be replaced the relevant copy
will be in the registers, which invalidates the copy in the lowcore. The
machine check handler needs to explicitly store registers 0-7 to the stack.
Cc: stable@vger.kernel.org
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/Kconfig.debug')
0 files changed, 0 insertions, 0 deletions