From: Julian Seward <jseward@acm.org>
Date: Sat, 10 Sep 2011 09:10:03 +0000 (+0000)
Subject: Properly preserve FP registers (and, more generally, the entire guest
X-Git-Tag: svn/VALGRIND_3_7_0~216
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0f9ced90ec19c346b02c79c4678c51cc40c0f15e;p=thirdparty%2Fvalgrind.git

Properly preserve FP registers (and, more generally, the entire guest
state) across signal deliveries.  Fixes #281488.



git-svn-id: svn://svn.valgrind.org/valgrind/trunk@12021
---

diff --git a/coregrind/m_sigframe/sigframe-arm-linux.c b/coregrind/m_sigframe/sigframe-arm-linux.c
index 47677005a4..988b9906f1 100644
--- a/coregrind/m_sigframe/sigframe-arm-linux.c
+++ b/coregrind/m_sigframe/sigframe-arm-linux.c
@@ -53,9 +53,19 @@
 #include "pub_core_transtab.h"      // VG_(discard_translations)
 
 
+/* This uses the hack of dumping the vex guest state along with both
+   shadows in the frame, and restoring it afterwards from there,
+   rather than pulling it out of the ucontext.  That means that signal
+   handlers which modify the ucontext and then return, expecting their
+   modifications to take effect, will have those modifications
+   ignored.  This could be fixed properly with an hour or so more
+   effort. */
+
+
 struct vg_sig_private {
    UInt magicPI;
    UInt sigNo_private;
+   VexGuestARMState vex;
    VexGuestARMState vex_shadow1;
    VexGuestARMState vex_shadow2;
 };
@@ -180,6 +190,7 @@ static void build_sigframe(ThreadState *tst,
 
    priv->magicPI = 0x31415927;
    priv->sigNo_private = sigNo;
+   priv->vex         = tst->arch.vex;
    priv->vex_shadow1 = tst->arch.vex_shadow1;
    priv->vex_shadow2 = tst->arch.vex_shadow2;
 
@@ -316,6 +327,9 @@ void VG_(sigframe_destroy)( ThreadId tid, Bool isRT )
    REST(pc,R15T);
 #  undef REST
 
+   /* Uh, the next line makes all the REST() above pointless. */
+   tst->arch.vex         = priv->vex;
+
    tst->arch.vex_shadow1 = priv->vex_shadow1;
    tst->arch.vex_shadow2 = priv->vex_shadow2;
 
@@ -325,7 +339,7 @@ void VG_(sigframe_destroy)( ThreadId tid, Bool isRT )
    if (VG_(clo_trace_signals))
       VG_(message)(Vg_DebugMsg,
                    "vg_pop_signal_frame (thread %d): "
-                   "isRT=%d valid magic; PC=%#x",
+                   "isRT=%d valid magic; PC=%#x\n",
                    tid, has_siginfo, tst->arch.vex.guest_R15T);
 
    /* tell the tools */