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[binutils-gdb] gdb/rs6000: Read backchain as unsigned.
- From: Marcin at sourceware dot org, Koś at sourceware dot org;cielnicki <mwk at sourceware dot org>
- To: gdb-cvs at sourceware dot org
- Date: 9 Mar 2016 17:48:33 -0000
- Subject: [binutils-gdb] gdb/rs6000: Read backchain as unsigned.
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=cc2c4da8813b980a4e68272bb43583f4af6fe89c
commit cc2c4da8813b980a4e68272bb43583f4af6fe89c
Author: Marcin KoÅ?cielnicki <koriakin@0x04.net>
Date: Sun Mar 6 16:38:52 2016 +0100
gdb/rs6000: Read backchain as unsigned.
Previously, backchain was read as a signed quantity, resulting in
addresses like 0xfffffffffffeded0 instead of 0xfffeded0 returned by
unwinder on 32-bit powerpc. While normally such addresses are masked
off, this causes problems for tracepoints, since 0xfffffffffffeded0
is considered unavailable.
Fixes a test failure in gdb.trace/entry-values.exp.
gdb/ChangeLog:
* corefile.c (safe_read_memory_unsigned_integer): New function.
* gdbcore.h (safe_read_memory_unsigned_integer): New prototype.
* rs6000-tdep.c (rs6000_frame_cache): Read backchain as unsigned.
Diff:
---
gdb/ChangeLog | 6 ++++++
gdb/corefile.c | 18 ++++++++++++++++++
gdb/gdbcore.h | 3 +++
gdb/rs6000-tdep.c | 6 +++---
4 files changed, 30 insertions(+), 3 deletions(-)
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 74dec87..83eef37 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,11 @@
2016-03-09 Marcin KoÅ?cielnicki <koriakin@0x04.net>
+ * corefile.c (safe_read_memory_unsigned_integer): New function.
+ * gdbcore.h (safe_read_memory_unsigned_integer): New prototype.
+ * rs6000-tdep.c (rs6000_frame_cache): Read backchain as unsigned.
+
+2016-03-09 Marcin KoÅ?cielnicki <koriakin@0x04.net>
+
* rs6000-tdep.c: Add "ax.h" and "ax-gdb.h" includes.
(rs6000_gen_return_address): New function.
(rs6000_gdbarch_init): Wire in the above.
diff --git a/gdb/corefile.c b/gdb/corefile.c
index dbdbafc..5ad4d40 100644
--- a/gdb/corefile.c
+++ b/gdb/corefile.c
@@ -306,6 +306,24 @@ safe_read_memory_integer (CORE_ADDR memaddr, int len,
return 1;
}
+/* Read memory at MEMADDR of length LEN and put the contents in
+ RETURN_VALUE. Return 0 if MEMADDR couldn't be read and non-zero
+ if successful. */
+
+int
+safe_read_memory_unsigned_integer (CORE_ADDR memaddr, int len,
+ enum bfd_endian byte_order,
+ ULONGEST *return_value)
+{
+ gdb_byte buf[sizeof (ULONGEST)];
+
+ if (target_read_memory (memaddr, buf, len))
+ return 0;
+
+ *return_value = extract_unsigned_integer (buf, len, byte_order);
+ return 1;
+}
+
LONGEST
read_memory_integer (CORE_ADDR memaddr, int len,
enum bfd_endian byte_order)
diff --git a/gdb/gdbcore.h b/gdb/gdbcore.h
index 5db80e5..8b101bc 100644
--- a/gdb/gdbcore.h
+++ b/gdb/gdbcore.h
@@ -76,6 +76,9 @@ extern int safe_read_memory_integer (CORE_ADDR memaddr, int len,
extern ULONGEST read_memory_unsigned_integer (CORE_ADDR memaddr,
int len,
enum bfd_endian byte_order);
+extern int safe_read_memory_unsigned_integer (CORE_ADDR memaddr, int len,
+ enum bfd_endian byte_order,
+ ULONGEST *return_value);
/* Read an integer from debugged code memory, given address,
number of bytes, and byte order for code. */
diff --git a/gdb/rs6000-tdep.c b/gdb/rs6000-tdep.c
index 565c620..2460eb5 100644
--- a/gdb/rs6000-tdep.c
+++ b/gdb/rs6000-tdep.c
@@ -3336,10 +3336,10 @@ rs6000_frame_cache (struct frame_info *this_frame, void **this_cache)
if (!fdata.frameless)
{
/* Frameless really means stackless. */
- LONGEST backchain;
+ ULONGEST backchain;
- if (safe_read_memory_integer (cache->base, wordsize,
- byte_order, &backchain))
+ if (safe_read_memory_unsigned_integer (cache->base, wordsize,
+ byte_order, &backchain))
cache->base = (CORE_ADDR) backchain;
}