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 <[EMAIL PROTECTED]>

diff -r -p -u z/linux-2.6.11/arch/x86_64/ia32/ptrace32.c 
linux-2.6.11/arch/x86_64/ia32/ptrace32.c
--- linux-2.6.12.3.orig/arch/x86_64/ia32/ptrace32.c     2005-03-02 
02:37:52.000000000 -0500
+++ linux-2.6.12.3/arch/x86_64/ia32/ptrace32.c  2005-07-31 15:29:48.000000000 
-0400
@@ -43,11 +43,11 @@ static int putreg32(struct task_struct *
        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 @@ static int getreg32(struct task_struct *
 
        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;

-- 
Daniel Jacobowitz
CodeSourcery, LLC
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to