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| author |  H. Peter Anvin <hpa@zytor.com>
| 2009-11-13 15:28:16 -0800 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com>
| 2009-11-16 13:44:59 -0800 |
| commit | 4763ed4d45522b876c97e1f7f4b659d211f75571 (patch) | |
| tree | ae053500de9f1c374e4b7f34d8f21d45a5b961d2 /arch/x86/kernel/setup.c | |
| parent | x86, pageattr: Make set_memory_(x|nx) aware of NX support (diff) | |
| download | linux-4763ed4d45522b876c97e1f7f4b659d211f75571.tar.gz linux-4763ed4d45522b876c97e1f7f4b659d211f75571.tar.bz2 linux-4763ed4d45522b876c97e1f7f4b659d211f75571.zip | |
x86, mm: Clean up and simplify NX enablement
The 32- and 64-bit code used very different mechanisms for enabling
NX, but even the 32-bit code was enabling NX in head_32.S if it is
available. Furthermore, we had a bewildering collection of tests for
the available of NX.
This patch:
a) merges the 32-bit set_nx() and the 64-bit check_efer() function
into a single x86_configure_nx() function. EFER control is left
to the head code.
b) eliminates the nx_enabled variable entirely. Things that need to
test for NX enablement can verify __supported_pte_mask directly,
and cpu_has_nx gives the supported status of NX.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Chris Wright <chrisw@sous-sol.org>
LKML-Reference: <1258154897-6770-5-git-send-email-hpa@zytor.com>
Acked-by: Kees Cook <kees.cook@canonical.com>
Diffstat (limited to 'arch/x86/kernel/setup.c')
| -rw-r--r-- | arch/x86/kernel/setup.c | 8 |
1 files changed, 2 insertions, 6 deletions
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 0a6e94ab8339..23b7f46bf843 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -787,21 +787,17 @@ void __init setup_arch(char **cmdline_p) strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE); *cmdline_p = command_line; -#ifdef CONFIG_X86_64 /* * Must call this twice: Once just to detect whether hardware doesn't * support NX (so that the early EHCI debug console setup can safely * call set_fixmap(), and then again after parsing early parameters to * honor the respective command line option. */ - check_efer(); -#endif + x86_configure_nx(); parse_early_param(); -#ifdef CONFIG_X86_64 - check_efer(); -#endif + x86_configure_nx(); /* Must be before kernel pagetables are setup */ vmi_activate(); |