From: Oliver Kurth <okurth@vmware.com>
Date: Wed, 10 Jun 2020 19:05:46 +0000 (-0700)
Subject: Make peeking back into the stack work for back traces
X-Git-Tag: stable-11.2.0~156
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0cfda58aaa8bc0fea56f1211897e7f2237f6070a;p=thirdparty%2Fopen-vm-tools.git

Make peeking back into the stack work for back traces

GCC 10 doesn't like peeking back before the end of an arrary (which
is used to peek into the stack).  Fix this.

https://github.com/vmware/open-vm-tools/issues/429
---

diff --git a/open-vm-tools/lib/user/utilBacktrace.c b/open-vm-tools/lib/user/utilBacktrace.c
index 998713656..d26d21e7d 100644
--- a/open-vm-tools/lib/user/utilBacktrace.c
+++ b/open-vm-tools/lib/user/utilBacktrace.c
@@ -343,7 +343,8 @@ UtilBacktraceFromPointerWithFunc(uintptr_t *basePtr,       // IN:
                                i, x[0], x[1], dli.dli_sname, dli.dli_fname,
                                 dli.dli_fbase);
       } else {
-         outFunc(outFuncData, "SymBacktrace[%d] %#08x eip %#08x \n", i, x[0], x[1]);
+         outFunc(outFuncData, "SymBacktrace[%d] %#08x eip %#08x \n", i, x[0],
+                 x[1]);
       }
       x = (uintptr_t *) x[0];
    }
@@ -394,6 +395,7 @@ Util_Backtrace(int bugNr) // IN
  *-----------------------------------------------------------------------------
  */
 
+
 void
 Util_BacktraceWithFunc(int bugNr,                // IN:
                        Util_OutputFunc outFunc,  // IN:
@@ -413,7 +415,7 @@ Util_BacktraceWithFunc(int bugNr,                // IN:
    if (bugNr == 0) {
       outFunc(outFuncData, "Backtrace:\n");
    } else {
-      outFunc(outFuncData, "Backtrace for bugNr=%d\n",bugNr);
+      outFunc(outFuncData, "Backtrace for bugNr=%d\n", bugNr);
    }
    frames = backtrace(callstack, ARRAYSIZE(callstack));
    for (i = 0; i < frames; i++) {
@@ -431,14 +433,14 @@ Util_BacktraceWithFunc(int bugNr,                // IN:
       }
    }
 #else
-   uintptr_t *x = (uintptr_t *) &bugNr;
-
    if (bugNr == 0) {
       outFunc(outFuncData, "Backtrace:\n");
    } else {
-      outFunc(outFuncData, "Backtrace for bugNr=%d\n",bugNr);
+      outFunc(outFuncData, "Backtrace for bugNr=%d\n", bugNr);
    }
-   /* coverity[ptr_arith] */
-   UtilBacktraceFromPointerWithFunc(&x[-2], outFunc, outFuncData);
+
+   UtilBacktraceFromPointerWithFunc(__builtin_frame_address(0), outFunc,
+                                    outFuncData);
 #endif
 }
+