ChangeLog:

[pf3gnuchains/gcc-fork.git] / gcc / config / s390 / linux.h

diff --git a/gcc/config/s390/linux.h b/gcc/config/s390/linux.h
index 9a6db9d..0f51ef7 100644 (file)
--- a/gcc/config/s390/linux.h
+++ b/gcc/config/s390/linux.h
@@ -113,6 +113,7 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
       } __attribute__ ((__aligned__ (8))) sigregs_;                    \
                                                                        \
     sigregs_ *regs_;                                                   \
+    int *signo_ = NULL;                                                        \
                                                                        \
     /* svc $__NR_sigreturn or svc $__NR_rt_sigreturn  */               \
     if (pc_[0] != 0x0a || (pc_[1] != 119 && pc_[1] != 173))            \
@@ -133,6 +134,7 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
          } *uc_ = (CONTEXT)->cfa + 8 + 128;                            \
                                                                        \
        regs_ = &uc_->uc_mcontext;                                      \
+       signo_ = (CONTEXT)->cfa + sizeof(long);                         \
       }                                                                        \
                                                                        \
     /* Old-style RT frame and all non-RT frames:                       \
@@ -141,6 +143,12 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
     else                                                               \
       {                                                                        \
        regs_ = *(sigregs_ **)((CONTEXT)->cfa + 8);                     \
+                                                                       \
+       /* Recent kernels store the signal number immediately after     \
+          the sigregs; old kernels have the return trampoline at       \
+          this location.  */                                           \
+       if ((void *)(regs_ + 1) != (CONTEXT)->ra)                       \
+         signo_ = (int *)(regs_ + 1);                                  \
       }                                                                        \
                                                                        \
     new_cfa_ = regs_->gprs[15] + 16*sizeof(long) + 32;                 \
@@ -163,10 +171,31 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
       }                                                                        \
                                                                        \
     /* Load return addr from PSW into dummy register 32.  */           \
+                                                                       \
     (FS)->regs.reg[32].how = REG_SAVED_OFFSET;                         \
     (FS)->regs.reg[32].loc.offset = (long)&regs_->psw_addr - new_cfa_; \
     (FS)->retaddr_column = 32;                                         \
                                                                        \
+    /* If we got a SIGSEGV or a SIGBUS, the PSW address points *to*    \
+       the faulting instruction, not after it.  This causes the logic  \
+       in unwind-dw2.c that decrements the RA to determine the correct \
+       CFI region to get confused.  To fix that, we *increment* the RA \
+       here in that case.  Note that we cannot modify the RA in place, \
+       and the frame state wants a *pointer*, not a value; thus we put \
+       the modified RA value into the unused register 33 slot of FS and        \
+       have the register 32 save address point to that slot.           \
+                                                                       \
+       Unfortunately, for regular signals on old kernels, we don't know        \
+       the signal number.  We default to not fiddling with the RA;     \
+       that can fail in rare cases.  Upgrade your kernel.  */          \
+                                                                       \
+    if (signo_ && (*signo_ == 11 || *signo_ == 7))                     \
+      {                                                                        \
+       (FS)->regs.reg[33].loc.exp = regs_->psw_addr + 1;               \
+       (FS)->regs.reg[32].loc.offset =                                 \
+               (long)&(FS)->regs.reg[33].loc.exp - new_cfa_;           \
+      }                                                                        \
+                                                                       \
     goto SUCCESS;                                                      \
   } while (0)