From 65afd0754fe419302efca95599b19e53ffca8dbd Mon Sep 17 00:00:00 2001
From: Pekka Enberg <penberg@cloudius-systems.com>
Date: Mon, 26 Aug 2013 14:20:58 +0300
Subject: [PATCH] runtime: Fix mincore() on an unmapped address
Fix mincore() to deal with unmapped addresses like msync() does.
This fixes a SIGSEGV in libunwind's access_mem() when leak detector is
enabled:
(gdb) bt
#0 page_fault (ef=0xffffc0003ffe7008) at ../../core/mmu.cc:871
#1 <signal handler called>
#2 ContiguousSpace::block_start_const (this=<optimized out>, p=0x77d2f3968)
at /usr/src/debug/java-1.7.0-openjdk-1.7.0.25-2.3.12.3.fc19.x86_64/openjdk/hotspot/src/share/vm/oops/oop.inline.hpp:411
#3 0x00001000008ae16c in GenerationBlockStartClosure::do_space (this=0x2000001f9100, s=<optimized out>)
at /usr/src/debug/java-1.7.0-openjdk-1.7.0.25-2.3.12.3.fc19.x86_64/openjdk/hotspot/src/share/vm/memory/generation.cpp:242
#4 0x00001000007f097c in DefNewGeneration::space_iterate (this=0xffffc0003fb68c00, blk=0x2000001f9100, usedOnly=<optimized out>)
at /usr/src/debug/java-1.7.0-openjdk-1.7.0.25-2.3.12.3.fc19.x86_64/openjdk/hotspot/src/share/vm/memory/defNewGeneration.cpp:480
#5 0x00001000008aca0e in Generation::block_start (this=<optimized out>, p=<optimized out>)
at /usr/src/debug/java-1.7.0-openjdk-1.7.0.25-2.3.12.3.fc19.x86_64/openjdk/hotspot/src/share/vm/memory/generation.cpp:251
#6 0x0000100000b06d2f in os::print_location (st=st@entry=0x2000001f9560, x=32165017960, verbose=verbose@entry=false)
at /usr/src/debug/java-1.7.0-openjdk-1.7.0.25-2.3.12.3.fc19.x86_64/openjdk/hotspot/src/share/vm/runtime/os.cpp:868
#7 0x0000100000b11b5b in os::print_register_info (st=0x2000001f9560, context=0x2000001f9740)
at /usr/src/debug/java-1.7.0-openjdk-1.7.0.25-2.3.12.3.fc19.x86_64/openjdk/hotspot/src/os_cpu/linux_x86/vm/os_linux_x86.cpp:839
#8 0x0000100000c6cde8 in VMError::report (this=0x2000001f9610, st=st@entry=0x2000001f9560)
at /usr/src/debug/java-1.7.0-openjdk-1.7.0.25-2.3.12.3.fc19.x86_64/openjdk/hotspot/src/share/vm/utilities/vmError.cpp:551
#9 0x0000100000c6da3b in VMError::report_and_die (this=this@entry=0x2000001f9610)
at /usr/src/debug/java-1.7.0-openjdk-1.7.0.25-2.3.12.3.fc19.x86_64/openjdk/hotspot/src/share/vm/utilities/vmError.cpp:984
#10 0x0000100000b1109f in JVM_handle_linux_signal (sig=11, info=0x2000001f9bb8, ucVoid=0x2000001f9740,
abort_if_unrecognized=<optimized out>)
at /usr/src/debug/java-1.7.0-openjdk-1.7.0.25-2.3.12.3.fc19.x86_64/openjdk/hotspot/src/os_cpu/linux_x86/vm/os_linux_x86.cpp:528
#11 0x000000000039f242 in call_signal_handler (frame=0x2000001f9b10) at ../../arch/x64/signal.cc:69
#12 <signal handler called>
#13 0x000000000057d721 in access_mem ()
#14 0x000000000057cb1d in dwarf_get ()
#15 0x000000000057ce51 in _ULx86_64_step ()
#16 0x00000000004315fd in backtrace (buffer=0x1ff9d80 <memory::alloc_tracker::remember(void*, int)::bt>, size=20)
at ../../libc/misc/backtrace.cc:16
#17 0x00000000003b8d99 in memory::alloc_tracker::remember (this=0x1777ae0 <memory::tracker>, addr=0xffffc0004508de00, size=54)
at ../../core/alloctracker.cc:59
#18 0x00000000003b0504 in memory::tracker_remember (addr=0xffffc0004508de00, size=54) at ../../core/mempool.cc:43
#19 0x00000000003b2152 in std_malloc (size=54) at ../../core/mempool.cc:723
#20 0x00000000003b259c in malloc (size=54) at ../../core/mempool.cc:856
#21 0x0000100001615e4c in JNU_GetStringPlatformChars (env=env@entry=0xffffc0003a4dc1d8, jstr=jstr@entry=0xffffc0004591b800,
isCopy=isCopy@entry=0x0) at ../../../src/share/native/common/jni_util.c:801
#22 0x000010000161ada6 in Java_java_io_UnixFileSystem_getBooleanAttributes0 (env=0xffffc0003a4dc1d8, this=<optimized out>,
file=<optimized out>) at ../../../src/solaris/native/java/io/UnixFileSystem_md.c:111
#23 0x000020000021ed8e in ?? ()
#24 0x00002000001faa58 in ?? ()
#25 0x00002000001faac0 in ?? ()
#26 0x00002000001faa50 in ?? ()
#27 0x0000000000000000 in ?? ()
Spotted by Avi Kivity.
---
runtime.cc | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/runtime.cc b/runtime.cc
index ea75e780e..b9dc598af 100644
--- a/runtime.cc
+++ b/runtime.cc
@@ -35,6 +35,8 @@
#include "bsd/sys/sys/sysctl.h"
#include <osv/power.hh>
#include <sys/time.h>
+#include "mmu.hh"
+#include "libc/libc.hh"
#define __LC_LAST 13
@@ -182,6 +184,9 @@ gid_t getegid(void)
int mincore(void *addr, size_t length, unsigned char *vec)
{
+ if (!mmu::ismapped(addr, length)) {
+ return libc_error(ENOMEM);
+ }
memset(vec, 0x01, (length + getpagesize() - 1) / getpagesize());
return 0;
}
--
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