Messages in this thread Patch in this message | | | Date | Fri, 28 Aug 2009 14:11:57 +0100 | From | "Jan Beulich" <> | Subject | [PATCH] x86-64: fix earlyprintk=dbgp for machines without NX |
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Since parse_early_param() may (e.g. for earlyprintk=dbgp) involve calls to page table manipulation functions (here set_fixmap_nocache()), NX hardware support must be determined before calling that function (so that __supported_pte_mask gets properly set up). But the call after parse_early_param() can also not go away, as that will honor eventual command line specified disabling of the NX functionality (this will then just result in whatever mappings got established during parse_early_param() having the NX bit set despite it being disabled on the command line, but I think that's tolerable).
Signed-off-by: Jan Beulich <jbeulich@novell.com> Cc: Yinghai Lu <yhlu.kernel@gmail.com>
--- arch/x86/kernel/setup.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
--- linux-2.6.31-rc8/arch/x86/kernel/setup.c 2009-08-28 14:57:38.000000000 +0200 +++ 2.6.31-rc8-x86_64-check-efer-earlier/arch/x86/kernel/setup.c 2009-08-28 14:52:33.000000000 +0200 @@ -796,6 +796,16 @@ 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 + parse_early_param(); #ifdef CONFIG_X86_64
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