| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20150116111019.GD18880@pd.tnic>
Date: Fri, 16 Jan 2015 12:10:19 +0100
From: Borislav Petkov <bp@...en8.de>
To: Thomas Gleixner <tglx@...utronix.de>
Cc: LKML <linux-kernel@...r.kernel.org>,
Jiang Liu <jiang.liu@...ux.intel.com>,
Joerg Roedel <joro@...tes.org>, x86@...nel.org,
Tony Luck <tony.luck@...el.com>
Subject: Re: [patch 04/23] x86/ioapic: Check x2apic really
On Thu, Jan 15, 2015 at 09:22:14PM -0000, Thomas Gleixner wrote:
> The x2apic_preenabled flag is just a horrible hack and if X2APIC
> support is disabled it does not reflect the actual hardware
> state. Check the hardware instead.
>
> Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
> ---
> arch/x86/include/asm/apic.h | 2 --
> arch/x86/kernel/apic/apic.c | 4 +++-
> arch/x86/kernel/apic/io_apic.c | 2 +-
> 3 files changed, 4 insertions(+), 4 deletions(-)
>
> Index: tip/arch/x86/include/asm/apic.h
> ===================================================================
> --- tip.orig/arch/x86/include/asm/apic.h
> +++ tip/arch/x86/include/asm/apic.h
> @@ -177,7 +177,6 @@ static inline u64 native_x2apic_icr_read
>
> extern int x2apic_mode;
> extern int x2apic_phys;
> -extern int x2apic_preenabled;
> extern void check_x2apic(void);
> extern void enable_x2apic(void);
> static inline int x2apic_enabled(void)
> @@ -209,7 +208,6 @@ static inline void x2apic_force_phys(voi
> }
>
> #define x2apic_mode (0)
> -#define x2apic_preenabled (0)
> #define x2apic_supported() (0)
> #endif
>
> Index: tip/arch/x86/kernel/apic/apic.c
> ===================================================================
> --- tip.orig/arch/x86/kernel/apic/apic.c
> +++ tip/arch/x86/kernel/apic/apic.c
> @@ -1480,7 +1480,7 @@ static bool nox2apic __initdata;
> #ifdef CONFIG_X86_X2APIC
> int x2apic_mode;
> /* x2apic enabled before OS handover */
> -int x2apic_preenabled;
> +static int x2apic_preenabled;
Bah, let's get rid of this knob completely (ontop of your patch):
---
Index: b/arch/x86/kernel/apic/apic.c
===================================================================
--- a/arch/x86/kernel/apic/apic.c 2015-01-16 12:09:08.116801555 +0100
+++ b/arch/x86/kernel/apic/apic.c 2015-01-16 12:08:41.004802076 +0100
@@ -1480,7 +1480,6 @@ static bool nox2apic __initdata;
#ifdef CONFIG_X86_X2APIC
int x2apic_mode;
/* x2apic enabled before OS handover */
-static int x2apic_preenabled;
static int x2apic_disabled;
static int __init setup_nox2apic(char *str)
{
@@ -1546,7 +1545,7 @@ void check_x2apic(void)
{
if (x2apic_enabled()) {
pr_info("x2apic enabled by BIOS, switching to x2apic ops\n");
- x2apic_preenabled = x2apic_mode = 1;
+ x2apic_mode = 1;
}
}
@@ -1570,7 +1569,6 @@ void enable_x2apic(void)
}
}
#else
-#define x2apic_preenabled (0)
#endif /* CONFIG_X86_X2APIC */
static int __init try_to_enable_IR(void)
@@ -1599,7 +1597,7 @@ static __init void try_to_enable_x2apic(
(IS_ENABLED(CONFIG_HYPERVISOR_GUEST) &&
!hypervisor_x2apic_available())) {
pr_info("IRQ remapping doesn't support X2APIC mode, disable x2apic.\n");
- if (x2apic_preenabled)
+ if (x2apic_enabled())
disable_x2apic();
return;
}
@@ -1643,7 +1641,7 @@ void __init enable_IR_x2apic(void)
legacy_pic->mask_all();
mask_ioapic_entries();
- if (x2apic_preenabled && nox2apic)
+ if (x2apic_enabled() && nox2apic)
disable_x2apic();
/* If irq_remapping_prepare() succeded, try to enable it */
if (ir_stat >= 0)
--
--
Regards/Gruss,
Boris.
Sent from a fat crate under my desk. Formatting is fine.
--
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists