From: Wang YanQing <udknight@gmail.com> To: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>, "H. Peter Anvin" <hpa@zytor.com>, Randy Dunlap <rdunlap@xenotime.net>, Stephen Rothwell <sfr@canb.auug.org.au>, linux-next@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>, Michal Januszewski <spock@gentoo.org>, linux-fbdev@vger.kernel.org, x86@kernel.org, Andrew Morton <akpm@linux-foundation.org> Subject: Re: [PATCH] x86: export 'pcibios_enabled' Date: Thu, 22 Mar 2012 08:41:35 +0800 [thread overview] Message-ID: <20120322004135.GA4253@udknight> (raw) In-Reply-To: <20120314112137.68fa4f70@pyramind.ukuu.org.uk> On Wed, Mar 14, 2012 at 11:21:37AM +0000, Alan Cox wrote: > You can use set_memory_x() to mark memory executable (and _nx to set it back). > NO I can't, if I set_memory_x and don't set pcibios_enabled = 1, then static_protections will still failed because pcibios_enabled == 0, and I don't want to use set_memory_x, because I don't want to give the user of uvesafb that feeling "I will lost BIOS NX protection if I choice uvesafb." > If you really need to know if NX is being used then the check > > if (__supported_pte_mask & PTE_NX) > > will do the trick and the variable is exported. I don't understand what do you mean, do you means CONFIG_X86_PAE for 32? Or CONFIG_X86_64? when NX is being used, the pci bios is NX or not also depend on ACPI.ACPI on or off all will influnce the code path in pci_arch_init, decide the set_bios_x have chance to execute or not.See https://lkml.org/lkml/2011/11/16/84 By the way _PAGE_NX instead of PTE_NX, right? > I'd suggest however you wrap that in a cpu_has_nx() type macro somewhere > in the arch headers. > The same above. > If you go poking around pcibios values you are going to get burned if > someone is ever bored enough to make NX and PCIBIOS work together > differently. > Indeed according to 5bd5a452662bc37c54fb6828db1a3faf87e6511c, who bring me the trouble, check the pcibios_enabled is the only simple and good way to resolve the Oops I meet. If you really don't want it, and if I am not all wrong about your "helper method", you means you want export the below: int check_pcibios_enabled()? See https://lkml.org/lkml/2012/2/26/124 Thanks.
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From: Wang YanQing <udknight@gmail.com> To: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>, "H. Peter Anvin" <hpa@zytor.com>, Randy Dunlap <rdunlap@xenotime.net>, Stephen Rothwell <sfr@canb.auug.org.au>, linux-next@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>, Michal Januszewski <spock@gentoo.org>, linux-fbdev@vger.kernel.org, x86@kernel.org, Andrew Morton <akpm@linux-foundation.org> Subject: Re: [PATCH] x86: export 'pcibios_enabled' Date: Thu, 22 Mar 2012 00:41:35 +0000 [thread overview] Message-ID: <20120322004135.GA4253@udknight> (raw) In-Reply-To: <20120314112137.68fa4f70@pyramind.ukuu.org.uk> On Wed, Mar 14, 2012 at 11:21:37AM +0000, Alan Cox wrote: > You can use set_memory_x() to mark memory executable (and _nx to set it back). > NO I can't, if I set_memory_x and don't set pcibios_enabled = 1, then static_protections will still failed because pcibios_enabled = 0, and I don't want to use set_memory_x, because I don't want to give the user of uvesafb that feeling "I will lost BIOS NX protection if I choice uvesafb." > If you really need to know if NX is being used then the check > > if (__supported_pte_mask & PTE_NX) > > will do the trick and the variable is exported. I don't understand what do you mean, do you means CONFIG_X86_PAE for 32? Or CONFIG_X86_64? when NX is being used, the pci bios is NX or not also depend on ACPI.ACPI on or off all will influnce the code path in pci_arch_init, decide the set_bios_x have chance to execute or not.See https://lkml.org/lkml/2011/11/16/84 By the way _PAGE_NX instead of PTE_NX, right? > I'd suggest however you wrap that in a cpu_has_nx() type macro somewhere > in the arch headers. > The same above. > If you go poking around pcibios values you are going to get burned if > someone is ever bored enough to make NX and PCIBIOS work together > differently. > Indeed according to 5bd5a452662bc37c54fb6828db1a3faf87e6511c, who bring me the trouble, check the pcibios_enabled is the only simple and good way to resolve the Oops I meet. If you really don't want it, and if I am not all wrong about your "helper method", you means you want export the below: int check_pcibios_enabled()? See https://lkml.org/lkml/2012/2/26/124 Thanks.
next prev parent reply other threads:[~2012-03-22 0:42 UTC|newest] Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top 2012-03-13 9:41 linux-next: Tree for Mar 13 Stephen Rothwell 2012-03-13 17:10 ` linux-next: Tree for Mar 13 (dlm / gfs2) Randy Dunlap 2012-03-13 20:30 ` [PATCH] x86: export 'pcibios_enabled' Randy Dunlap 2012-03-13 20:30 ` Randy Dunlap 2012-03-14 0:43 ` H. Peter Anvin 2012-03-14 0:43 ` H. Peter Anvin 2012-03-14 9:29 ` Alan Cox 2012-03-14 10:59 ` Florian Tobias Schandinat 2012-03-14 11:21 ` Alan Cox 2012-03-22 0:41 ` Wang YanQing [this message] 2012-03-22 0:41 ` Wang YanQing 2012-03-26 0:27 ` Wang YanQing 2012-03-26 0:27 ` Wang YanQing 2012-03-16 0:41 ` Wang YanQing 2012-03-16 0:41 ` Wang YanQing 2012-03-19 0:30 ` Wang YanQing 2012-03-19 0:30 ` Wang YanQing 2012-03-19 1:03 ` [PATCH v2] x86: export 'pcibios_enabled' as GPL Randy Dunlap 2012-03-19 1:03 ` Randy Dunlap 2012-03-21 4:37 ` Wang YanQing 2012-03-21 4:37 ` Wang YanQing 2012-03-21 9:29 ` Alan Cox 2012-03-13 21:06 ` linux-next: Tree for Mar 13 (ata) Randy Dunlap 2012-03-13 21:22 ` Jeff Garzik 2012-03-14 0:36 ` Dan Williams
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