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[pushed] Fix gdbserver --debug issues caught by Valgrind
- From: Pedro Alves <palves at redhat dot com>
- To: gdb-patches at sourceware dot org
- Date: Thu, 6 Aug 2015 13:41:30 +0100
- Subject: [pushed] Fix gdbserver --debug issues caught by Valgrind
- Authentication-results: sourceware.org; auth=none
Running gdbserver --debug under Valgrind shows:
==4803== Invalid read of size 4
==4803== at 0x432B62: linux_write_memory (linux-low.c:5320)
==4803== by 0x4143F7: write_inferior_memory (target.c:83)
==4803== by 0x415895: remove_memory_breakpoint (mem-break.c:362)
==4803== by 0x432EF5: linux_remove_point (linux-low.c:5460)
==4803== by 0x416319: delete_raw_breakpoint (mem-break.c:802)
==4803== by 0x4163F3: release_breakpoint (mem-break.c:842)
==4803== by 0x416477: delete_breakpoint_1 (mem-break.c:869)
==4803== by 0x4164EF: delete_breakpoint (mem-break.c:891)
==4803== by 0x416843: delete_gdb_breakpoint_1 (mem-break.c:1069)
==4803== by 0x4168D8: delete_gdb_breakpoint (mem-break.c:1098)
==4803== by 0x4134E3: process_serial_event (server.c:4051)
==4803== by 0x4138E4: handle_serial_event (server.c:4196)
==4803== Address 0x4c6b930 is 0 bytes inside a block of size 1 alloc'd
==4803== at 0x4A0645D: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==4803== by 0x4240C6: xmalloc (common-utils.c:43)
==4803== by 0x41439C: write_inferior_memory (target.c:80)
==4803== by 0x415895: remove_memory_breakpoint (mem-break.c:362)
==4803== by 0x432EF5: linux_remove_point (linux-low.c:5460)
==4803== by 0x416319: delete_raw_breakpoint (mem-break.c:802)
==4803== by 0x4163F3: release_breakpoint (mem-break.c:842)
==4803== by 0x416477: delete_breakpoint_1 (mem-break.c:869)
==4803== by 0x4164EF: delete_breakpoint (mem-break.c:891)
==4803== by 0x416843: delete_gdb_breakpoint_1 (mem-break.c:1069)
==4803== by 0x4168D8: delete_gdb_breakpoint (mem-break.c:1098)
==4803== by 0x4134E3: process_serial_event (server.c:4051)
==4803==
And:
==7272== Conditional jump or move depends on uninitialised value(s)
==7272== at 0x3615E48361: vfprintf (vfprintf.c:1634)
==7272== by 0x414E89: debug_vprintf (debug.c:60)
==7272== by 0x42800A: debug_printf (common-debug.c:35)
==7272== by 0x43937B: my_waitpid (linux-waitpid.c:149)
==7272== by 0x42D740: linux_wait_for_event_filtered (linux-low.c:2441)
==7272== by 0x42DADA: linux_wait_for_event (linux-low.c:2552)
==7272== by 0x42E165: linux_wait_1 (linux-low.c:2860)
==7272== by 0x42F5D8: linux_wait (linux-low.c:3453)
==7272== by 0x4144A4: mywait (target.c:107)
==7272== by 0x413969: handle_target_event (server.c:4214)
==7272== by 0x41A1A6: handle_file_event (event-loop.c:429)
==7272== by 0x41996D: process_event (event-loop.c:184)
gdb/ChangeLog:
2015-08-06 Pedro Alves <palves@redhat.com>
* nat/linux-waitpid.c (my_waitpid): Only print *status if waitpid
returned > 0.
gdb/gdbserver/ChangeLog:
2015-08-06 Pedro Alves <palves@redhat.com>
* linux-low.c (linux_write_memory): Rewrite debug output to avoid
reading beyond the passed in buffer length.
---
gdb/ChangeLog | 5 +++++
gdb/gdbserver/ChangeLog | 5 +++++
gdb/gdbserver/linux-low.c | 22 +++++++++++++---------
gdb/nat/linux-waitpid.c | 2 +-
4 files changed, 24 insertions(+), 10 deletions(-)
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 591fe25..193581f 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2015-08-06 Pedro Alves <palves@redhat.com>
+
+ * nat/linux-waitpid.c (my_waitpid): Only print *status if waitpid
+ returned > 0.
+
2015-08-06 Pierre Langlois <pierre.langlois@arm.com>
* common/agent.c (symbol_list) <required>: Remove.
diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog
index e45050a..79904d9 100644
--- a/gdb/gdbserver/ChangeLog
+++ b/gdb/gdbserver/ChangeLog
@@ -1,3 +1,8 @@
+2015-08-06 Pedro Alves <palves@redhat.com>
+
+ * linux-low.c (linux_write_memory): Rewrite debug output to avoid
+ reading beyond the passed in buffer length.
+
2015-08-06 Pierre Langlois <pierre.langlois@arm.com>
* tracepoint.c (symbol_list) <required>: Remove.
diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c
index 98fffc9..2146a2c 100644
--- a/gdb/gdbserver/linux-low.c
+++ b/gdb/gdbserver/linux-low.c
@@ -5336,15 +5336,19 @@ linux_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len)
if (debug_threads)
{
/* Dump up to four bytes. */
- unsigned int val = * (unsigned int *) myaddr;
- if (len == 1)
- val = val & 0xff;
- else if (len == 2)
- val = val & 0xffff;
- else if (len == 3)
- val = val & 0xffffff;
- debug_printf ("Writing %0*x to 0x%08lx in process %d\n",
- 2 * ((len < 4) ? len : 4), val, (long)memaddr, pid);
+ char str[4 * 2 + 1];
+ char *p = str;
+ int dump = len < 4 ? len : 4;
+
+ for (i = 0; i < dump; i++)
+ {
+ sprintf (p, "%02x", myaddr[i]);
+ p += 2;
+ }
+ *p = '\0';
+
+ debug_printf ("Writing %s to 0x%08lx in process %d\n",
+ str, (long) memaddr, pid);
}
/* Fill start and end extra bytes of buffer with existing memory data. */
diff --git a/gdb/nat/linux-waitpid.c b/gdb/nat/linux-waitpid.c
index 97149bd..cbcdd95 100644
--- a/gdb/nat/linux-waitpid.c
+++ b/gdb/nat/linux-waitpid.c
@@ -144,7 +144,7 @@ my_waitpid (int pid, int *status, int flags)
}
linux_debug ("my_waitpid (%d, 0x%x): status(%x), %d\n",
- pid, flags, status ? *status : -1, ret);
+ pid, flags, (ret > 0 && status != NULL) ? *status : -1, ret);
errno = out_errno;
return ret;
--
1.9.3