From: Paul Floyd <pjfloyd@wanadoo.fr>
Date: Tue, 9 Nov 2021 22:11:15 +0000 (+0100)
Subject: Bug 445032 valgrind/memcheck crash with SIGSEGV when SIGVTALRM timer used and libthr... 
X-Git-Tag: VALGRIND_3_19_0~98
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4b8eddfde14291e288a7017edce5c7225e1533d6;p=thirdparty%2Fvalgrind.git

Bug 445032 valgrind/memcheck crash with SIGSEGV when SIGVTALRM timer used and libthr.so associated

The problem was that 'struct sigframe' has both a uContext struct
member and a puContext pointer to that struct. And puContext wasn't
being initialized to point to uContext.

It seems that the pthread sigreturn code uses puContext on i386.
amd64, with register arguments, didn't have this problem.
---

diff --git a/NEWS b/NEWS
index 888f07bb6b..c6e9361a14 100644
--- a/NEWS
+++ b/NEWS
@@ -46,6 +46,8 @@ are not entered into bugzilla tend to get forgotten about or ignored.
 444571  PPC, fix the lxsibzx and lxsihzx so they only load their respective
         sized data.
 444836  PPC, pstq instruction for R=1 is not storing to the correct address.
+445032  valgrind/memcheck crash with SIGSEGV when SIGVTALRM timer used and
+        libthr.so associated
 
 To see details of a given bug, visit
   https://bugs.kde.org/show_bug.cgi?id=XXXXXX
diff --git a/coregrind/m_sigframe/sigframe-x86-freebsd.c b/coregrind/m_sigframe/sigframe-x86-freebsd.c
index a1d8638e5a..12f51e385c 100644
--- a/coregrind/m_sigframe/sigframe-x86-freebsd.c
+++ b/coregrind/m_sigframe/sigframe-x86-freebsd.c
@@ -304,6 +304,8 @@ static Addr build_sigframe(ThreadState *tst,
       err = 0;
    }
 
+   frame->puContext =  (Addr)&frame->uContext;
+
    synth_ucontext(tst->tid, siginfo, trapno, err, mask,
                   &frame->uContext, &frame->fpstate);