Bug 538339 In fpehandler() mask cw and back to the faulting x87 instruction on Solaris r=gal,bsmedberg

toolkit/xre/nsSigHandlers.cpp

@@ -64,6 +64,7 @@
 
 #if defined(SOLARIS)
 #include <sys/resource.h>
+#include <ucontext.h>
 #endif
 
 #ifdef XP_BEOS
@@ -259,6 +260,32 @@ static void fpehandler(int signum, siginfo_t *si, void *context)
   *mxcsr &= ~SSE_STATUS_FLAGS; /* clear all pending SSE exceptions */
 #endif
 #endif
+#ifdef SOLARIS
+  ucontext_t *uc = (ucontext_t *)context;
+
+#if defined(__i386)
+  uint32_t *cw = &uc->uc_mcontext.fpregs.fp_reg_set.fpchip_state.state[0];
+  *cw |= FPU_EXCEPTION_MASK;
+
+  uint32_t *sw = &uc->uc_mcontext.fpregs.fp_reg_set.fpchip_state.state[1];
+  *sw &= ~FPU_STATUS_FLAGS;
+
+  /* address of the instruction that caused the exception */
+  uint32_t *ip = &uc->uc_mcontext.fpregs.fp_reg_set.fpchip_state.state[3];
+  uc->uc_mcontext.gregs[REG_PC] = *ip;
+#endif
+#if defined(__amd64__)
+  uint16_t *cw = &uc->uc_mcontext.fpregs.fp_reg_set.fpchip_state.cw;
+  *cw |= FPU_EXCEPTION_MASK;
+
+  uint16_t *sw = &uc->uc_mcontext.fpregs.fp_reg_set.fpchip_state.sw;
+  *sw &= ~FPU_STATUS_FLAGS;
+
+  uint32_t *mxcsr = &uc->uc_mcontext.fpregs.fp_reg_set.fpchip_state.mxcsr;
+  *mxcsr |= SSE_EXCEPTION_MASK; /* disable all SSE exceptions */
+  *mxcsr &= ~SSE_STATUS_FLAGS; /* clear all pending SSE exceptions */
+#endif
+#endif
 }
 
 void InstallSignalHandlers(const char *ProgramName)

toolkit/xre/nsSigHandlers.h

@@ -36,7 +36,7 @@
  *
  * ***** END LICENSE BLOCK ***** */
 
-#if defined(_M_IX86) || defined(__i386__) || defined(__amd64__)
+#if defined(_M_IX86) || defined(__i386__) || defined(__i386) || defined(__amd64__)
 
 /*
  * x87 FPU Control Word: