I can confirm this resolved the problem. Thanks again for the
incredibly quick fix!
Tested-by: Brad Spengler <spender@xxxxxxxxxxxxxx>
-Brad
On Fri, Feb 19, 2010 at 03:20:11PM -0800, David Miller wrote:
>
> Here's the fix, thanks again for the report:
>
> sparc64: Fix sun4u execute bit check in TSB I-TLB load.
>
> Thanks to testcase and report from Brad Spengler:
>
> --------------------
> #include <stdio.h>
>
> typedef int (* _wee)(void);
>
> int main(void)
> {
> char buf[8] = { '\x81', '\xc7', '\xe0', '\x08', '\x81', '\xe8',
> '\x00', '\x00' };
> _wee wee;
> printf("%p\n", &buf);
> wee = (_wee)&buf;
> wee();
>
> return 0;
> }
> --------------------
>
> TSB I-tlb load code tries to use andcc to check the _PAGE_EXEC_4U bit,
> but that's bit 12 so it gets sign extended all the way up to bit 63
> and the test nearly always passes as a result.
>
> Use sethi to fix the bug.
>
> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
> ---
> arch/sparc/kernel/tsb.S | 6 ++++--
> 1 files changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/arch/sparc/kernel/tsb.S b/arch/sparc/kernel/tsb.S
> index 8c91d9b..db15d12 100644
> --- a/arch/sparc/kernel/tsb.S
> +++ b/arch/sparc/kernel/tsb.S
> @@ -191,10 +191,12 @@ tsb_dtlb_load:
>
> tsb_itlb_load:
> /* Executable bit must be set. */
> -661: andcc %g5, _PAGE_EXEC_4U, %g0
> - .section .sun4v_1insn_patch, "ax"
> +661: sethi %hi(_PAGE_EXEC_4U), %g4
> + andcc %g5, %g4, %g0
> + .section .sun4v_2insn_patch, "ax"
> .word 661b
> andcc %g5, _PAGE_EXEC_4V, %g0
> + nop
> .previous
>
> be,pn %xcc, tsb_do_fault
> --
> 1.6.6.1
Attachment:
signature.asc
Description: Digital signature
