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| author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2015-07-06 17:58:19 +0200 |
|---|---|---|
| committer | Sasha Levin <sasha.levin@oracle.com> | 2015-08-27 13:25:40 -0400 |
| commit | d9698525c8e9f5236d74e36df8a828b6dcc23861 (patch) | |
| tree | aed38fdd741c09c9ab90f9261be2b1f71414d8e4 /arch/s390 | |
| parent | 0d814959f8d53f7782c73192cd1c7eaa2c0c3920 (diff) | |
s390/sclp: clear upper register halves in _sclp_print_early
[ Upstream commit f9c87a6f46d508eae0d9ae640be98d50f237f827 ]
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.
Cc: <stable@vger.kernel.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Diffstat (limited to 'arch/s390')
| -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 |