[PATCH] x86_64: fix 32-bit thread debugging
The IA32 ptrace emulation currently returns the wrong registers for fs/gs;
it's returning what x86_64 calls gs_base. We need regs.gsindex in order
for GDB to correctly locate the TLS area. Without this patch, the 32-bit
GDB testsuite bombs on a 64-bit kernel. With it, results look about like
I'd expect, although there are still a handful of kernel-related failures
(vsyscall related?).
Signed-off-by: Daniel Jacobowitz <dan@codesourcery.com>
Acked-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/x86_64/ia32/ptrace32.c b/arch/x86_64/ia32/ptrace32.c
index b98b6d2..2a925e2 100644
--- a/arch/x86_64/ia32/ptrace32.c
+++ b/arch/x86_64/ia32/ptrace32.c
@@ -43,11 +43,11 @@
switch (regno) {
case offsetof(struct user32, regs.fs):
if (val && (val & 3) != 3) return -EIO;
- child->thread.fs = val & 0xffff;
+ child->thread.fsindex = val & 0xffff;
break;
case offsetof(struct user32, regs.gs):
if (val && (val & 3) != 3) return -EIO;
- child->thread.gs = val & 0xffff;
+ child->thread.gsindex = val & 0xffff;
break;
case offsetof(struct user32, regs.ds):
if (val && (val & 3) != 3) return -EIO;
@@ -138,10 +138,10 @@
switch (regno) {
case offsetof(struct user32, regs.fs):
- *val = child->thread.fs;
+ *val = child->thread.fsindex;
break;
case offsetof(struct user32, regs.gs):
- *val = child->thread.gs;
+ *val = child->thread.gsindex;
break;
case offsetof(struct user32, regs.ds):
*val = child->thread.ds;