diff options
| author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2015-07-06 17:58:19 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-08-10 12:20:29 -0700 |
| commit | 3a893ef1923c6f93ca477ff583efe893ff98a109 (patch) | |
| tree | b9627bf39eb7e7fc66be25f9c663a3d56009291a | |
| parent | 518309e081d6328daf443531c3a70cbb10277006 (diff) | |
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -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 29bd7bec4176..1ecd47b5e250 100644 --- a/arch/s390/kernel/sclp.S +++ b/arch/s390/kernel/sclp.S @@ -276,6 +276,8 @@ 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 @@ -299,6 +301,8 @@ 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 |