config.host (i[34567]86-*-freebsd*, [...]): Set md_unwind_header

        * config.host (i[34567]86-*-freebsd*, x86_64-*-freebsd*): Set
        md_unwind_header
        * config/i386/freebsd-unwind.h: New.

From-SVN: r223765

3 files changed, 181 insertions, 0 deletions

diff --git a/libgcc/ChangeLog b/libgcc/ChangeLog
index 1bcd266..fb4d2ba 100644
--- a/libgcc/ChangeLog
+++ b/libgcc/ChangeLog
@@ -1,3 +1,9 @@
+2015-05-27  John Marino <gnugcc@marino.st>
+
+	* config.host (i[34567]86-*-freebsd*, x86_64-*-freebsd*): Set
+	md_unwind_header
+	* config/i386/freebsd-unwind.h: New.
+
 2015-05-22  Uros Bizjak  <ubizjak@gmail.com>
 
 	* config.host (i[34567]-*-*, x86_64-*-*): Add t-crtfm instead of
diff --git a/libgcc/config.host b/libgcc/config.host
index 05fd808..46666df 100644
--- a/libgcc/config.host
+++ b/libgcc/config.host
@@ -578,9 +578,11 @@ x86_64-*-dragonfly*)
 	;;
 i[34567]86-*-freebsd*)
 	tmake_file="${tmake_file} i386/t-freebsd i386/t-crtstuff"
+	md_unwind_header=i386/freebsd-unwind.h
 	;;
 x86_64-*-freebsd*)
 	tmake_file="${tmake_file} i386/t-freebsd i386/t-crtstuff"
+	md_unwind_header=i386/freebsd-unwind.h
 	;;
 i[34567]86-*-netbsdelf*)
 	;;
diff --git a/libgcc/config/i386/freebsd-unwind.h b/libgcc/config/i386/freebsd-unwind.h
new file mode 100644
index 0000000..b83ba0d
--- /dev/null
+++ b/libgcc/config/i386/freebsd-unwind.h
@@ -0,0 +1,173 @@
+/* DWARF2 EH unwinding support for FreeBSD: AMD x86-64 and x86.
+   Copyright (C) 2015 Free Software Foundation, Inc.
+   Contributed by John Marino <gnugcc@marino.st>
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+<http://www.gnu.org/licenses/>.  */
+
+/* Do code reading to identify a signal frame, and set the frame
+   state data appropriately.  See unwind-dw2.c for the structs. */
+
+#include <sys/types.h>
+#include <signal.h>
+#include <sys/ucontext.h>
+#include <machine/sigframe.h>
+
+#define REG_NAME(reg)	sf_uc.uc_mcontext.mc_## reg
+
+#ifdef __x86_64__
+#define MD_FALLBACK_FRAME_STATE_FOR x86_64_freebsd_fallback_frame_state
+
+static _Unwind_Reason_Code
+x86_64_freebsd_fallback_frame_state
+(struct _Unwind_Context *context, _Unwind_FrameState *fs)
+{
+  struct sigframe *sf;
+  long new_cfa;
+
+  /* Prior to FreeBSD 9, the signal trampoline was located immediately
+     before the ps_strings.  To support non-executable stacks on AMD64,
+     the sigtramp was moved to a shared page for FreeBSD 9.  Unfortunately
+     this means looking frame patterns again (sys/amd64/amd64/sigtramp.S)
+     rather than using the robust and convenient KERN_PS_STRINGS trick.
+
+     <pc + 00>:  lea     0x10(%rsp),%rdi
+     <pc + 05>:  pushq   $0x0
+     <pc + 17>:  mov     $0x1a1,%rax
+     <pc + 14>:  syscall
+
+     If we can't find this pattern, we're at the end of the stack.
+  */
+
+  if (!(   *(unsigned int *)(context->ra)      == 0x247c8d48
+        && *(unsigned int *)(context->ra +  4) == 0x48006a10
+        && *(unsigned int *)(context->ra +  8) == 0x01a1c0c7
+        && *(unsigned int *)(context->ra + 12) == 0x050f0000 ))
+    return _URC_END_OF_STACK;
+
+  sf = (struct sigframe *) context->cfa;
+  new_cfa = sf->REG_NAME(rsp);
+  fs->regs.cfa_how = CFA_REG_OFFSET;
+  /* Register 7 is rsp  */
+  fs->regs.cfa_reg = 7;
+  fs->regs.cfa_offset = new_cfa - (long) context->cfa;
+
+  /* The SVR4 register numbering macros aren't usable in libgcc.  */
+  fs->regs.reg[0].how = REG_SAVED_OFFSET;
+  fs->regs.reg[0].loc.offset = (long)&sf->REG_NAME(rax) - new_cfa;
+  fs->regs.reg[1].how = REG_SAVED_OFFSET;
+  fs->regs.reg[1].loc.offset = (long)&sf->REG_NAME(rdx) - new_cfa;
+  fs->regs.reg[2].how = REG_SAVED_OFFSET;
+  fs->regs.reg[2].loc.offset = (long)&sf->REG_NAME(rcx) - new_cfa;
+  fs->regs.reg[3].how = REG_SAVED_OFFSET;
+  fs->regs.reg[3].loc.offset = (long)&sf->REG_NAME(rbx) - new_cfa;
+  fs->regs.reg[4].how = REG_SAVED_OFFSET;
+  fs->regs.reg[4].loc.offset = (long)&sf->REG_NAME(rsi) - new_cfa;
+  fs->regs.reg[5].how = REG_SAVED_OFFSET;
+  fs->regs.reg[5].loc.offset = (long)&sf->REG_NAME(rdi) - new_cfa;
+  fs->regs.reg[6].how = REG_SAVED_OFFSET;
+  fs->regs.reg[6].loc.offset = (long)&sf->REG_NAME(rbp) - new_cfa;
+  fs->regs.reg[8].how = REG_SAVED_OFFSET;
+  fs->regs.reg[8].loc.offset = (long)&sf->REG_NAME(r8) - new_cfa;
+  fs->regs.reg[9].how = REG_SAVED_OFFSET;
+  fs->regs.reg[9].loc.offset = (long)&sf->REG_NAME(r9) - new_cfa;
+  fs->regs.reg[10].how = REG_SAVED_OFFSET;
+  fs->regs.reg[10].loc.offset = (long)&sf->REG_NAME(r10) - new_cfa;
+  fs->regs.reg[11].how = REG_SAVED_OFFSET;
+  fs->regs.reg[11].loc.offset = (long)&sf->REG_NAME(r11) - new_cfa;
+  fs->regs.reg[12].how = REG_SAVED_OFFSET;
+  fs->regs.reg[12].loc.offset = (long)&sf->REG_NAME(r12) - new_cfa;
+  fs->regs.reg[13].how = REG_SAVED_OFFSET;
+  fs->regs.reg[13].loc.offset = (long)&sf->REG_NAME(r13) - new_cfa;
+  fs->regs.reg[14].how = REG_SAVED_OFFSET;
+  fs->regs.reg[14].loc.offset = (long)&sf->REG_NAME(r14) - new_cfa;
+  fs->regs.reg[15].how = REG_SAVED_OFFSET;
+  fs->regs.reg[15].loc.offset = (long)&sf->REG_NAME(r15) - new_cfa;
+  fs->regs.reg[16].how = REG_SAVED_OFFSET;
+  fs->regs.reg[16].loc.offset = (long)&sf->REG_NAME(rip) - new_cfa;
+  fs->retaddr_column = 16;
+  fs->signal_frame = 1;
+  return _URC_NO_REASON;
+}
+
+#else /* Next section is for i386  */
+
+#define MD_FALLBACK_FRAME_STATE_FOR x86_freebsd_fallback_frame_state
+
+/*
+ * We can't use KERN_PS_STRINGS anymore if we want to support FreeBSD32
+ * compat on AMD64.  The sigtramp is in a shared page in that case so the
+ * x86_sigtramp_range only works on a true i386 system.  We have to
+ * search for the sigtramp frame if we want it working everywhere.
+ */
+
+static _Unwind_Reason_Code
+x86_freebsd_fallback_frame_state
+(struct _Unwind_Context *context, _Unwind_FrameState *fs)
+{
+  struct sigframe *sf;
+  long new_cfa;
+
+/*
+ * i386 sigtramp frame we are looking for follows.
+ * Apparently PSL_VM is variable, so we can't look past context->ra + 4
+ * <sigcode>:
+ *   0:	ff 54 24 10          	call   *0x10(%esp)          *SIGF_HANDLER
+ *   4:	8d 44 24 20          	lea    0x20(%esp),%eax       SIGF_UC
+ *   8:	50                   	push   %eax
+ *   9:	f7 40 54 00 00 02 00 	testl  $0x20000,0x54(%eax)  $PSL_VM
+ *  10:	75 03                	jne    15 <sigcode+0x15>
+ *  12:	8e 68 14             	mov    0x14(%eax),%gs        UC_GS
+ *  15:	b8 a1 01 00 00       	mov    0x1a1,%eax           $SYS_sigreturn
+ */
+
+  if (!(   *(unsigned int *)(context->ra - 4) == 0x102454ff
+        && *(unsigned int *)(context->ra)     == 0x2024448d ))
+    return _URC_END_OF_STACK;
+
+  sf = (struct sigframe *) context->cfa;
+  new_cfa = sf->REG_NAME(esp);
+  fs->regs.cfa_how = CFA_REG_OFFSET;
+  fs->regs.cfa_reg = 4;
+  fs->regs.cfa_offset = new_cfa - (long) context->cfa;
+
+  /* The SVR4 register numbering macros aren't usable in libgcc.  */
+  fs->regs.reg[0].how = REG_SAVED_OFFSET;
+  fs->regs.reg[0].loc.offset = (long)&sf->REG_NAME(eax) - new_cfa;
+  fs->regs.reg[3].how = REG_SAVED_OFFSET;
+  fs->regs.reg[3].loc.offset = (long)&sf->REG_NAME(ebx) - new_cfa;
+  fs->regs.reg[1].how = REG_SAVED_OFFSET;
+  fs->regs.reg[1].loc.offset = (long)&sf->REG_NAME(ecx) - new_cfa;
+  fs->regs.reg[2].how = REG_SAVED_OFFSET;
+  fs->regs.reg[2].loc.offset = (long)&sf->REG_NAME(edx) - new_cfa;
+  fs->regs.reg[6].how = REG_SAVED_OFFSET;
+  fs->regs.reg[6].loc.offset = (long)&sf->REG_NAME(esi) - new_cfa;
+  fs->regs.reg[7].how = REG_SAVED_OFFSET;
+  fs->regs.reg[7].loc.offset = (long)&sf->REG_NAME(edi) - new_cfa;
+  fs->regs.reg[5].how = REG_SAVED_OFFSET;
+  fs->regs.reg[5].loc.offset = (long)&sf->REG_NAME(ebp) - new_cfa;
+  fs->regs.reg[8].how = REG_SAVED_OFFSET;
+  fs->regs.reg[8].loc.offset = (long)&sf->REG_NAME(eip) - new_cfa;
+  fs->retaddr_column = 8;
+  fs->signal_frame = 1;
+  return _URC_NO_REASON;
+}
+#endif /* ifdef __x86_64__  */