FreeBSD x86: Remove fallback for detecting signal trampolines by address.

A few FreeBSD releases did not include the page holding the signal
code in core dumps.  As a workaround, a sysctl was used to fetch the
default location of the signal code instead.  The youngest affected
FreeBSD release is 10.1 released in November 2014 and EOLed in
December 2016.  The fallback only works for native processes and would
require a separate unwinder once the FreeBSD arches are converted to
use tramp_frame for signal frames.

1 files changed, 0 insertions, 28 deletions

diff --git a/gdb/amd64-fbsd-nat.c b/gdb/amd64-fbsd-nat.c
index 376e1ff..3c79a40 100644
--- a/gdb/amd64-fbsd-nat.c
+++ b/gdb/amd64-fbsd-nat.c
@@ -278,32 +278,4 @@ Please report this to <bug-gdb@gnu.org>."),
     }
 
   SC_RBP_OFFSET = offset;
-
-#ifdef KERN_PROC_SIGTRAMP
-  /* Normally signal frames are detected via amd64fbsd_sigtramp_p.
-     However, FreeBSD 9.2 through 10.1 do not include the page holding
-     the signal code in core dumps.  These releases do provide a
-     kern.proc.sigtramp.<pid> sysctl that returns the location of the
-     signal trampoline for a running process.  We fetch the location
-     of the current (gdb) process and use this to identify signal
-     frames in core dumps from these releases.  Note that this only
-     works for core dumps of 64-bit (FreeBSD/amd64) processes and does
-     not handle core dumps of 32-bit (FreeBSD/i386) processes.  */
-  {
-    int mib[4];
-    struct kinfo_sigtramp kst;
-    size_t len;
-
-    mib[0] = CTL_KERN;
-    mib[1] = KERN_PROC;
-    mib[2] = KERN_PROC_SIGTRAMP;
-    mib[3] = getpid ();
-    len = sizeof (kst);
-    if (sysctl (mib, 4, &kst, &len, NULL, 0) == 0)
-      {
-	amd64fbsd_sigtramp_start_addr = (uintptr_t) kst.ksigtramp_start;
-	amd64fbsd_sigtramp_end_addr = (uintptr_t) kst.ksigtramp_end;
-      }
-  }
-#endif
 }