[Xen-changelog] [qemu-upstream-unstable] linux-user: Fix broken m68k signal handling on 64 bit hosts

[patchbot@xxxxxxx]

commit 09e2753be0e7841ae0045a87ee974e47ba10befd
Author:     Peter Maydell <peter.maydell@xxxxxxxxxx>
AuthorDate: Mon Dec 22 17:47:00 2014 +0000
Commit:     Michael Roth <mdroth@xxxxxxxxxxxxxxxxxx>
CommitDate: Sun Feb 22 18:09:36 2015 -0600

    linux-user: Fix broken m68k signal handling on 64 bit hosts
    
    The m68k signal frame setup code which writes the signal return
    trampoline code to the stack was assuming that a 'long' was 32 bits;
    on 64 bit systems this meant we would end up writing the 32 bit
    (2 insn) trampoline sequence to retaddr+4,retaddr+6 instead of
    the intended retaddr+0,retaddr+2, resulting in a guest crash when
    it tried to execute the invalid zero-bytes at retaddr+0.
    Fix by using uint32_t instead; also use uint16_t rather than short
    for consistency. This fixes bug LP:1404690.
    
    Reported-by: Michel Boaventura
    Signed-off-by: Peter Maydell <peter.maydell@xxxxxxxxxx>
    Signed-off-by: Riku Voipio <riku.voipio@xxxxxxxxxx>
    (cherry picked from commit 1669add752d9f29283f8ebf6a863d7b1e2d0f146)
    Signed-off-by: Michael Roth <mdroth@xxxxxxxxxxxxxxxxxx>
---
 linux-user/signal.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/linux-user/signal.c b/linux-user/signal.c
index e11b208..a324fd1 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -5091,7 +5091,7 @@ static void setup_frame(int sig, struct target_sigaction 
*ka,
     /* moveq #,d0; trap #0 */
 
     __put_user(0x70004e40 + (TARGET_NR_sigreturn << 16),
-                      (long *)(frame->retcode));
+                      (uint32_t *)(frame->retcode));
 
     /* Set up to return from userspace */
 
@@ -5225,8 +5225,8 @@ static void setup_rt_frame(int sig, struct 
target_sigaction *ka,
     /* moveq #,d0; notb d0; trap #0 */
 
     __put_user(0x70004600 + ((TARGET_NR_rt_sigreturn ^ 0xff) << 16),
-               (long *)(frame->retcode + 0));
-    __put_user(0x4e40, (short *)(frame->retcode + 4));
+               (uint32_t *)(frame->retcode + 0));
+    __put_user(0x4e40, (uint16_t *)(frame->retcode + 4));
 
     if (err)
         goto give_sigsegv;
--
generated by git-patchbot for /home/xen/git/qemu-upstream-unstable.git

_______________________________________________
Xen-changelog mailing list
Xen-changelog@xxxxxxxxxxxxx
http://lists.xensource.com/xen-changelog