Package: user-mode-linux
Version: 3.2-1um-1
Severity: normal
Tags: patch
Hi!
Using gdbserver inside an UML instance displays "Couldn't write debug
register". I have discovered this patch from Barry Friedman which works
fine for me:
http://www.mail-archive.com/user-mode-linux-devel@lists.sourceforge.net/msg06753.html
I also attach a version rebased for Linux 3.2.
-- System Information:
Debian Release: wheezy/sid
APT prefers unstable
APT policy: (500, 'unstable'), (500, 'testing'), (101, 'experimental')
Architecture: amd64 (x86_64)
Kernel: Linux 3.2.0-2-amd64 (SMP w/4 CPU cores)
Locale: LANG=fr_FR.utf8, LC_CTYPE=fr_FR.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Versions of packages user-mode-linux depends on:
ii libc6 2.13-33
ii uml-utilities 20070815-1.3
user-mode-linux recommends no packages.
Versions of packages user-mode-linux suggests:
ii rootstrap 0.3.24-6.1
ii rxvt-unicode [x-terminal-emulator] 9.15-1
ii slirp <none>
ii terminator [x-terminal-emulator] 0.95-1
ii user-mode-linux-doc 20060501-1
ii vde2 2.3.2-4
ii xterm [x-terminal-emulator] 278-1
-- no debconf information
diff --git a/arch/x86/um/ptrace_64.c b/arch/x86/um/ptrace_64.c
index 3b52bf0..583070c 100644
--- a/arch/x86/um/ptrace_64.c
+++ b/arch/x86/um/ptrace_64.c
@@ -120,7 +120,7 @@ int poke_user(struct task_struct *child, long addr, long data)
else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
(addr <= offsetof(struct user, u_debugreg[7]))) {
addr -= offsetof(struct user, u_debugreg[0]);
- addr = addr >> 2;
+ addr = addr >> 3;
if ((addr == 4) || (addr == 5))
return -EIO;
child->thread.arch.debugregs[addr] = data;
@@ -187,7 +187,7 @@ int peek_user(struct task_struct *child, long addr, long data)
else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
(addr <= offsetof(struct user, u_debugreg[7]))) {
addr -= offsetof(struct user, u_debugreg[0]);
- addr = addr >> 2;
+ addr = addr >> 3;
tmp = child->thread.arch.debugregs[addr];
}
return put_user(tmp, (unsigned long *) data);
