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[PATCH 4/4] Test ability to access unwritten-to mmap data in core file
- From: Kevin Buettner <kevinb at redhat dot com>
- To: gdb-patches at sourceware dot org
- Cc: Kevin Buettner <kevinb at redhat dot com>
- Date: Wed, 4 Mar 2020 17:42:43 -0700
- Subject: [PATCH 4/4] Test ability to access unwritten-to mmap data in core file
- References: <20200305004243.334607-1-kevinb@redhat.com>
gdb/testsuite/ChangeLog:
* gdb.base/corefile.exp (accessing anonymous, unwritten-to mmap data):
New test.
* gdb.base/coremaker.c (buf3): New global.
(mmapdata): Add mmap call which uses MAP_ANONYMOUSE and MAP_PRIVATE
flags.
Change-Id: Ifb8d77b06050e1220f33f83f1bec27533e4d9ead
---
gdb/testsuite/gdb.base/corefile.exp | 6 ++++++
gdb/testsuite/gdb.base/coremaker.c | 10 ++++++++++
2 files changed, 16 insertions(+)
diff --git a/gdb/testsuite/gdb.base/corefile.exp b/gdb/testsuite/gdb.base/corefile.exp
index 34b903b350..d46b38704c 100644
--- a/gdb/testsuite/gdb.base/corefile.exp
+++ b/gdb/testsuite/gdb.base/corefile.exp
@@ -175,6 +175,12 @@ gdb_test_multiple "x/8bd buf2" "$test" {
}
}
+# Test ability to read anonymous and, more importantly, unwritten-to
+# mmap'd data.
+
+gdb_test "x/wx buf3" "$hex:\[ \t\]+0x00000000" \
+ "accessing anonymous, unwritten-to mmap data"
+
# test reinit_frame_cache
gdb_load ${binfile}
diff --git a/gdb/testsuite/gdb.base/coremaker.c b/gdb/testsuite/gdb.base/coremaker.c
index 55330fd3e8..3a01c16405 100644
--- a/gdb/testsuite/gdb.base/coremaker.c
+++ b/gdb/testsuite/gdb.base/coremaker.c
@@ -38,6 +38,7 @@
char *buf1;
char *buf2;
+char *buf3;
int coremaker_data = 1; /* In Data section */
int coremaker_bss; /* In BSS section */
@@ -98,6 +99,15 @@ mmapdata ()
}
/* Touch buf2 so kernel writes it out into 'core'. */
buf2[0] = buf1[0];
+
+ /* Create yet another region which is allocated, but not written to. */
+ buf3 = mmap (NULL, MAPSIZE, PROT_READ | PROT_WRITE,
+ MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+ if (buf3 == (char *) -1)
+ {
+ perror ("mmap failed");
+ return;
+ }
}
void
--
2.24.1