| Message ID | 1438893418-16122-1-git-send-email-kamal@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/arch/s390/kernel/sclp.S b/arch/s390/kernel/sclp.S index 29bd7be..1ecd47b 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
This is a note to let you know that I have just added a patch titled s390/sclp: clear upper register halves in _sclp_print_early to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.13.y-queue This patch is scheduled to be released in version 3.13.11-ckt25. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.13.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From 5dbef0122e8997ef4e74a93184e1983f8a022e10 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky <schwidefsky@de.ibm.com> Date: Mon, 6 Jul 2015 17:58:19 +0200 Subject: 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: Kamal Mostafa <kamal@canonical.com> --- arch/s390/kernel/sclp.S | 4 ++++ 1 file changed, 4 insertions(+) -- 1.9.1