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| author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2015-07-06 17:58:19 +0200 |
|---|---|---|
| committer | Luis Henriques <luis.henriques@canonical.com> | 2015-08-12 09:48:34 +0100 |
| commit | 65f9f71dfb040e93957f4dbab19fb8456c88a6bc (patch) | |
| tree | 7b30641e8c125b7d009263d4c8cd55a8289836af /arch/s390/kernel | |
| parent | e2f9d514f507652f580ad221f820e382a820a1ae (diff) | |
| download | linux-stable-65f9f71dfb040e93957f4dbab19fb8456c88a6bc.tar.gz linux-stable-65f9f71dfb040e93957f4dbab19fb8456c88a6bc.tar.bz2 linux-stable-65f9f71dfb040e93957f4dbab19fb8456c88a6bc.zip | |
s390/sclp: clear upper register halves in _sclp_print_early
commit f9c87a6f46d508eae0d9ae640be98d50f237f827 upstream.
If the kernel is compiled with gcc 5.1 and the XZ compression option
the decompress_kernel function calls _sclp_print_early in 64-bit mode
while the content of the upper register half of %r6 is non-zero.
This causes a specification exception on the servc instruction in
_sclp_servc.
The _sclp_print_early function saves and restores the upper registers
halves but it fails to clear them for the 31-bit code of the mini sclp
driver.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
Diffstat (limited to 'arch/s390/kernel')
| -rw-r--r-- | arch/s390/kernel/sclp.S | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/s390/kernel/sclp.S b/arch/s390/kernel/sclp.S index a41f2c99dcc8..a0c4e7652647 100644 --- a/arch/s390/kernel/sclp.S +++ b/arch/s390/kernel/sclp.S @@ -277,6 +277,8 @@ ENTRY(_sclp_print_early) jno .Lesa2 ahi %r15,-80 stmh %r6,%r15,96(%r15) # store upper register halves + basr %r13,0 + lmh %r0,%r15,.Lzeroes-.(%r13) # clear upper register halves .Lesa2: #endif lr %r10,%r2 # save string pointer @@ -300,6 +302,8 @@ ENTRY(_sclp_print_early) #endif lm %r6,%r15,120(%r15) # restore registers br %r14 +.Lzeroes: + .fill 64,4,0 .LwritedataS4: .long 0x00760005 # SCLP command for write data |