From: Andy Lutomirski <luto@kernel.org>
To: X86 ML <x86@kernel.org>
Cc: Borislav Petkov <bpetkov@suse.de>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Brian Gerst <brgerst@gmail.com>,
Dave Hansen <dave.hansen@intel.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Andy Lutomirski <luto@kernel.org>
Subject: [PATCH v3 03/19] x86/gdt: Put per-cpu GDT remaps in ascending order
Date: Thu, 23 Nov 2017 20:32:49 -0800 [thread overview]
Message-ID: <3966a6edf6fd45deca4cf52a9b9276402499dda9.1511497875.git.luto@kernel.org> (raw)
In-Reply-To: <cover.1511497874.git.luto@kernel.org>
In-Reply-To: <cover.1511497874.git.luto@kernel.org>
We currently have CPU 0's GDT at the top of the GDT range and
higher-numbered CPUs at lower addresses. This happens because the
fixmap is upside down (index 0 is the top of the fixmap).
Flip it so that GDTs are in ascending order by virtual address.
This will simplify a future patch that will generalize the GDT
remap to contain multiple pages.
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
arch/x86/include/asm/desc.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/desc.h b/arch/x86/include/asm/desc.h
index 4011cb03ef08..95cd95eb7285 100644
--- a/arch/x86/include/asm/desc.h
+++ b/arch/x86/include/asm/desc.h
@@ -63,7 +63,7 @@ static inline struct desc_struct *get_current_gdt_rw(void)
/* Get the fixmap index for a specific processor */
static inline unsigned int get_cpu_gdt_ro_index(int cpu)
{
- return FIX_GDT_REMAP_BEGIN + cpu;
+ return FIX_GDT_REMAP_END - cpu;
}
/* Provide the fixmap address of the remapped GDT */
--
2.13.6
next prev parent reply other threads:[~2017-11-24 4:36 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-24 4:32 [PATCH v3 00/19] Entry stack switching Andy Lutomirski
2017-11-24 4:32 ` [PATCH v3 01/19] x86/asm/64: Allocate and enable the SYSENTER stack Andy Lutomirski
2017-11-24 4:32 ` [PATCH v3 02/19] x86/dumpstack: Add get_stack_info() support for " Andy Lutomirski
2017-11-24 4:32 ` Andy Lutomirski [this message]
2017-11-24 4:32 ` [PATCH v3 04/19] x86/fixmap: Generalize the GDT fixmap mechanism Andy Lutomirski
2017-11-24 4:32 ` [PATCH v3 05/19] x86/kasan/64: Teach KASAN about the cpu_entry_area Andy Lutomirski
2017-11-24 13:16 ` Andrey Ryabinin
2017-11-24 16:27 ` Andy Lutomirski
2017-11-24 17:21 ` [PATCH v4] x86/mm/kasan: " Andrey Ryabinin
2017-11-24 19:26 ` Andy Lutomirski
2017-11-24 17:26 ` [PATCH v3 05/19] x86/kasan/64: " Andrey Ryabinin
2017-11-24 4:32 ` [PATCH v3 06/19] x86/asm: Fix assumptions that the HW TSS is at the beginning of cpu_tss Andy Lutomirski
2017-11-24 4:32 ` [PATCH v3 07/19] x86/dumpstack: Handle stack overflow on all stacks Andy Lutomirski
2017-11-24 4:32 ` [PATCH v3 08/19] x86/asm: Move SYSENTER_stack to the beginning of struct tss_struct Andy Lutomirski
2017-11-24 4:32 ` [PATCH v3 09/19] x86/asm: Remap the TSS into the cpu entry area Andy Lutomirski
2017-11-24 4:32 ` [PATCH v3 10/19] x86/asm/64: Separate cpu_current_top_of_stack from TSS.sp0 Andy Lutomirski
2017-11-24 4:32 ` [PATCH v3 11/19] x86/espfix/64: Stop assuming that pt_regs is on the entry stack Andy Lutomirski
2017-11-24 4:32 ` [PATCH v3 12/19] x86/asm/64: Use a percpu trampoline stack for IDT entries Andy Lutomirski
2017-11-24 4:32 ` [PATCH v3 13/19] x86/asm/64: Return to userspace from the trampoline stack Andy Lutomirski
2017-11-24 4:33 ` [PATCH v3 14/19] x86/entry/64: Create a percpu SYSCALL entry trampoline Andy Lutomirski
2017-11-24 11:39 ` David Laight
2017-12-01 5:56 ` Andy Lutomirski
2017-11-24 4:33 ` [PATCH v3 15/19] x86/irq: Remove an old outdated comment about context tracking races Andy Lutomirski
2017-11-24 4:33 ` [PATCH v3 16/19] x86/irq/64: In the stack overflow warning, print the offending IP Andy Lutomirski
2017-11-24 4:33 ` [PATCH v3 17/19] x86/entry/64: Move the IST stacks into cpu_entry_area Andy Lutomirski
2017-11-24 4:33 ` [PATCH v3 18/19] x86/entry/64: Remove the SYSENTER stack canary Andy Lutomirski
2017-11-24 4:33 ` [PATCH v3 19/19] x86/entry: Clean up SYSENTER_stack code Andy Lutomirski
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