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 12:21:52 -0700 |
| commit | 88b7166f0d995edd9884a4641d2a0bca77b52090 (patch) | |
| tree | 6a9502665305bff6d65d66475a886eed429da4aa /arch | |
| parent | 5e62f6843f4071e5cbb021c00737ebd0673ebf18 (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>
Diffstat (limited to 'arch')
| -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 43c3169ea49c..ada0c07fe1a8 100644 --- a/arch/s390/kernel/sclp.S +++ b/arch/s390/kernel/sclp.S @@ -270,6 +270,8 @@ 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: lr %r10,%r2 # save string pointer lhi %r2,0 @@ -291,6 +293,8 @@ ENTRY(_sclp_print_early) .Lesa3: lm %r6,%r15,120(%r15) # restore registers br %r14 +.Lzeroes: + .fill 64,4,0 .LwritedataS4: .long 0x00760005 # SCLP command for write data |