From 94cd915f48523bbcbe20f74835d7f5a9d0b3a916 Mon Sep 17 00:00:00 2001
From: Michael Snyder <msnyder@vmware.com>
Date: Tue, 8 Jan 2002 00:59:31 +0000
Subject: [PATCH] 2002-01-07 Michael Snyder <msnyder@redhat.com>
* infptrace.c (GDB_MAX_ALLOCA): New define.
(child_xfer_memory): Use xmalloc/xfree instead of alloca if the
size of the buffer exceeds GDB_MAX_ALLOCA (default 1 megabyte,
can be overridden with whatever value is appropriate to the host).
* infttrace.c (child_xfer_memory): Add FIXME warning about use of
alloca to allocate potentially large buffer.
* rs6000-nat.c (child_xfer_memory): Ditto.
* symm-nat.c (child_xfer_memory): Ditto.
* x86-64-linux-nat.c (child_xfer_memory): Ditto.
---
gdb/ChangeLog | 12 ++++++++++++
gdb/infptrace.c | 22 ++++++++++++++++++++--
gdb/infttrace.c | 5 ++++-
gdb/symm-nat.c | 5 ++++-
gdb/x86-64-linux-nat.c | 6 ++++--
5 files changed, 44 insertions(+), 6 deletions(-)
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 4b5b530fab..f6b07d1f4b 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,15 @@
+2002-01-07 Michael Snyder <msnyder@redhat.com>
+
+ * infptrace.c (GDB_MAX_ALLOCA): New define.
+ (child_xfer_memory): Use xmalloc/xfree instead of alloca if the
+ size of the buffer exceeds GDB_MAX_ALLOCA (default 1 megabyte,
+ can be overridden with whatever value is appropriate to the host).
+ * infttrace.c (child_xfer_memory): Add FIXME warning about use of
+ alloca to allocate potentially large buffer.
+ * rs6000-nat.c (child_xfer_memory): Ditto.
+ * symm-nat.c (child_xfer_memory): Ditto.
+ * x86-64-linux-nat.c (child_xfer_memory): Ditto.
+
2002-01-07 Jackie Smith Cashion <jsmith@redhat.com>
From Nick Clifton <nickc@redhat.com>
diff --git a/gdb/infptrace.c b/gdb/infptrace.c
index 9815e05ef0..c39ca030e7 100644
--- a/gdb/infptrace.c
+++ b/gdb/infptrace.c
@@ -480,6 +480,11 @@ store_inferior_registers (int regno)
#endif /* !defined (FETCH_INFERIOR_REGISTERS). */
+/* Set an upper limit on alloca. */
+#ifndef GDB_MAX_ALLOCA
+#define GDB_MAX_ALLOCA 0x1000
+#endif
+
#if !defined (CHILD_XFER_MEMORY)
/* NOTE! I tried using PTRACE_READDATA, etc., to read and write memory
in the NEW_SUN_PTRACE case. It ought to be straightforward. But
@@ -506,9 +511,20 @@ child_xfer_memory (CORE_ADDR memaddr, char *myaddr, int len, int write,
/* Round ending address up; get number of longwords that makes. */
int count = ((((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
/ sizeof (PTRACE_XFER_TYPE));
+ int alloc = count * sizeof (PTRACE_XFER_TYPE);
+ PTRACE_XFER_TYPE *buffer;
+ struct cleanup *old_chain = NULL;
+
/* Allocate buffer of that many longwords. */
- PTRACE_XFER_TYPE *buffer =
- (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
+ if (len < GDB_MAX_ALLOCA)
+ {
+ buffer = (PTRACE_XFER_TYPE *) alloca (alloc);
+ }
+ else
+ {
+ buffer = (PTRACE_XFER_TYPE *) xmalloc (alloc);
+ old_chain = make_cleanup (xfree, buffer);
+ }
if (write)
{
@@ -573,6 +589,8 @@ child_xfer_memory (CORE_ADDR memaddr, char *myaddr, int len, int write,
len);
}
+ if (old_chain != NULL)
+ do_cleanups (old_chain);
return len;
}
diff --git a/gdb/infttrace.c b/gdb/infttrace.c
index c3216a5f0e..df0a5e579d 100644
--- a/gdb/infttrace.c
+++ b/gdb/infttrace.c
@@ -4922,8 +4922,11 @@ child_xfer_memory (CORE_ADDR memaddr, char *myaddr, int len, int write,
= (((memaddr + len) - addr) + sizeof (TTRACE_XFER_TYPE) - 1)
/ sizeof (TTRACE_XFER_TYPE);
/* Allocate buffer of that many longwords. */
+ /* FIXME (alloca): This code, cloned from infptrace.c, is unsafe
+ because it uses alloca to allocate a buffer of arbitrary size.
+ For very large xfers, this could crash GDB's stack. */
register TTRACE_XFER_TYPE *buffer
- = (TTRACE_XFER_TYPE *) alloca (count * sizeof (TTRACE_XFER_TYPE));
+ = (TTRACE_XFER_TYPE *) alloca (count * sizeof (TTRACE_XFER_TYPE));
if (write)
{
diff --git a/gdb/symm-nat.c b/gdb/symm-nat.c
index 183fa9198d..d686777431 100644
--- a/gdb/symm-nat.c
+++ b/gdb/symm-nat.c
@@ -764,8 +764,11 @@ child_xfer_memory (CORE_ADDR memaddr, char *myaddr, int len, int write,
= (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
/ sizeof (PTRACE_XFER_TYPE);
/* Allocate buffer of that many longwords. */
+ /* FIXME (alloca): This code, cloned from infptrace.c, is unsafe
+ because it uses alloca to allocate a buffer of arbitrary size.
+ For very large xfers, this could crash GDB's stack. */
register PTRACE_XFER_TYPE *buffer
- = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
+ = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
if (write)
{
diff --git a/gdb/x86-64-linux-nat.c b/gdb/x86-64-linux-nat.c
index 268aad583b..85912e8138 100644
--- a/gdb/x86-64-linux-nat.c
+++ b/gdb/x86-64-linux-nat.c
@@ -147,8 +147,7 @@ fill_gregset (elf_gregset_t * gregsetp, int regno)
for (i = 0; i < X86_64_NUM_GREGS; i++)
if ((regno == -1 || regno == i))
- *(regp + x86_64_regmap[i]) =
- *(elf_greg_t *) & registers[REGISTER_BYTE (i)];
+ read_register_gen (i, regp + x86_64_regmap[i]);
}
/* Fetch all general-purpose registers from process/thread TID and
@@ -417,6 +416,9 @@ child_xfer_memory (CORE_ADDR memaddr, char *myaddr, int len, int write,
= (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
/ sizeof (PTRACE_XFER_TYPE);
/* Allocate buffer of that many longwords. */
+ /* FIXME (alloca): This code, cloned from infptrace.c, is unsafe
+ because it uses alloca to allocate a buffer of arbitrary size.
+ For very large xfers, this could crash GDB's stack. */
register PTRACE_XFER_TYPE *buffer
= (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
--
2.42.0