From: Ingo Molnar <mingo@kernel.org>
To: linux-kernel@vger.kernel.org
Cc: Dave Hansen <dave.hansen@linux.intel.com>,
Andy Lutomirski <luto@amacapital.net>,
Thomas Gleixner <tglx@linutronix.de>,
"H . Peter Anvin" <hpa@zytor.com>,
Peter Zijlstra <peterz@infradead.org>,
Borislav Petkov <bp@alien8.de>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: [PATCH 07/24] x86/mm/kaiser: Map the CPU entry area
Date: Mon, 27 Nov 2017 11:49:06 +0100 [thread overview]
Message-ID: <20171127104923.14378-8-mingo@kernel.org> (raw)
In-Reply-To: <20171127104923.14378-1-mingo@kernel.org>
From: Dave Hansen <dave.hansen@linux.intel.com>
There is now a special 'struct cpu_entry_area' that contains all
of the data needed to enter the kernel. It's mapped in the fixmap
area and contains:
* The GDT (hardware segment descriptor)
* The TSS (thread information structure that points the hardware
to the various stacks, and contains the entry stack).
* The entry trampoline code itself
* The exception stacks (aka IRQ stacks)
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-mm@kvack.org
Cc: michael.schwarz@iaik.tugraz.at
Cc: moritz.lipp@iaik.tugraz.at
Cc: richard.fellner@student.tugraz.at
Link: https://lkml.kernel.org/r/20171123003453.D4CB33A9@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/include/asm/kaiser.h | 6 ++++++
arch/x86/kernel/cpu/common.c | 4 ++++
arch/x86/mm/kaiser.c | 31 +++++++++++++++++++++++++++++++
include/linux/kaiser.h | 3 +++
4 files changed, 44 insertions(+)
diff --git a/arch/x86/include/asm/kaiser.h b/arch/x86/include/asm/kaiser.h
index 3c2cc71b4058..040cb096d29d 100644
--- a/arch/x86/include/asm/kaiser.h
+++ b/arch/x86/include/asm/kaiser.h
@@ -33,6 +33,12 @@
extern int kaiser_add_mapping(unsigned long addr, unsigned long size,
unsigned long flags);
+/**
+ * kaiser_add_mapping_cpu_entry - map the cpu entry area
+ * @cpu: the CPU for which the entry area is being mapped
+ */
+extern void kaiser_add_mapping_cpu_entry(int cpu);
+
/**
* kaiser_remove_mapping - remove a kernel mapping from the userpage tables
* @addr: the start address of the range
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 1509f09abf5e..7b348cc33e2d 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -4,6 +4,7 @@
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/percpu.h>
+#include <linux/kaiser.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/delay.h>
@@ -584,6 +585,9 @@ static inline void setup_cpu_entry_area(int cpu)
__set_fixmap(get_cpu_entry_area_index(cpu, entry_trampoline),
__pa_symbol(_entry_trampoline), PAGE_KERNEL_RX);
#endif
+ /* CPU 0's mapping is done in kaiser_init() */
+ if (cpu)
+ kaiser_add_mapping_cpu_entry(cpu);
}
/* Load the original GDT from the per-cpu structure */
diff --git a/arch/x86/mm/kaiser.c b/arch/x86/mm/kaiser.c
index 72dc15364390..10c0e9e6bf6b 100644
--- a/arch/x86/mm/kaiser.c
+++ b/arch/x86/mm/kaiser.c
@@ -353,6 +353,26 @@ static void __init kaiser_init_all_pgds(void)
WARN_ON(__ret); \
} while (0)
+void kaiser_add_mapping_cpu_entry(int cpu)
+{
+ kaiser_add_user_map_early(get_cpu_gdt_ro(cpu), PAGE_SIZE,
+ __PAGE_KERNEL_RO);
+
+ /* includes the entry stack */
+ kaiser_add_user_map_early(&get_cpu_entry_area(cpu)->tss,
+ sizeof(get_cpu_entry_area(cpu)->tss),
+ __PAGE_KERNEL | _PAGE_GLOBAL);
+
+ /* Entry code, so needs to be EXEC */
+ kaiser_add_user_map_early(&get_cpu_entry_area(cpu)->entry_trampoline,
+ sizeof(get_cpu_entry_area(cpu)->entry_trampoline),
+ __PAGE_KERNEL_RX | _PAGE_GLOBAL);
+
+ kaiser_add_user_map_early(&get_cpu_entry_area(cpu)->exception_stacks,
+ sizeof(get_cpu_entry_area(cpu)->exception_stacks),
+ __PAGE_KERNEL | _PAGE_GLOBAL);
+}
+
extern char __per_cpu_user_mapped_start[], __per_cpu_user_mapped_end[];
/*
* If anything in here fails, we will likely die on one of the
@@ -393,6 +413,17 @@ void __init kaiser_init(void)
kaiser_add_user_map_early((void *)idt_descr.address,
sizeof(gate_desc) * NR_VECTORS,
__PAGE_KERNEL_RO | _PAGE_GLOBAL);
+
+ /*
+ * We delay CPU 0's mappings because these structures are
+ * created before the page allocator is up. Deferring it
+ * until here lets us use the plain page allocator
+ * unconditionally in the page table code above.
+ *
+ * This is OK because kaiser_init() is called long before
+ * we ever run userspace and need the KAISER mappings.
+ */
+ kaiser_add_mapping_cpu_entry(0);
}
int kaiser_add_mapping(unsigned long addr, unsigned long size,
diff --git a/include/linux/kaiser.h b/include/linux/kaiser.h
index 0fd800efa95c..77db4230a0dd 100644
--- a/include/linux/kaiser.h
+++ b/include/linux/kaiser.h
@@ -25,5 +25,8 @@ static inline int kaiser_add_mapping(unsigned long addr, unsigned long size,
return 0;
}
+static inline void kaiser_add_mapping_cpu_entry(int cpu)
+{
+}
#endif /* !CONFIG_KAISER */
#endif /* _INCLUDE_KAISER_H */
--
2.14.1
next prev parent reply other threads:[~2017-11-27 10:51 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-27 10:48 [PATCH 00/24] x86/mm: Add KAISER support Ingo Molnar
2017-11-27 10:49 ` [PATCH 01/24] x86/mm/kaiser: Disable global pages by default with KAISER Ingo Molnar
2017-11-27 10:49 ` [PATCH 02/24] x86/mm/kaiser: Prepare the x86/entry assembly code for entry/exit CR3 switching Ingo Molnar
2017-11-27 17:31 ` Peter Zijlstra
2017-11-27 17:33 ` Thomas Gleixner
2017-11-27 21:00 ` Peter Zijlstra
2017-11-27 10:49 ` [PATCH 03/24] x86/mm/kaiser: Introduce user-mapped per-CPU areas Ingo Molnar
2017-11-27 10:49 ` [PATCH 04/24] x86/mm/kaiser: Unmap kernel mappings from userspace page tables, core patch Ingo Molnar
2017-11-27 15:39 ` Peter Zijlstra
2017-11-27 17:04 ` Borislav Petkov
2017-11-27 19:17 ` Dave Hansen
2017-11-28 10:34 ` Peter Zijlstra
2017-11-27 10:49 ` [PATCH 05/24] x86/mm/kaiser: Allow NX poison to be set in p4d/pgd Ingo Molnar
2017-11-27 10:49 ` [PATCH 06/24] x86/mm/kaiser: Make sure the static PGDs are 8k in size Ingo Molnar
2017-11-27 10:49 ` Ingo Molnar [this message]
2017-11-27 10:49 ` [PATCH 08/24] x86/mm/kaiser: Map the dynamically-allocated LDTs Ingo Molnar
2017-11-29 22:03 ` [08/24] " Guenter Roeck
2017-11-27 10:49 ` [PATCH 09/24] x86/mm/kaiser: Map the espfix structures Ingo Molnar
2017-11-27 10:49 ` [PATCH 10/24] x86/mm/kaiser: Map the entry stack variables Ingo Molnar
2017-11-27 17:22 ` Peter Zijlstra
2017-11-27 17:32 ` Thomas Gleixner
2017-11-27 21:00 ` Peter Zijlstra
2017-11-27 17:29 ` Peter Zijlstra
2017-11-27 17:32 ` Thomas Gleixner
2017-11-27 10:49 ` [PATCH 11/24] x86/mm/kaiser: Map virtually-addressed performance monitoring buffers Ingo Molnar
2017-11-27 10:49 ` [PATCH 12/24] x86/mm: Move the CR3 construction functions to tlbflush.h Ingo Molnar
2017-11-27 10:49 ` [PATCH 13/24] x86/mm: Remove hard-coded ASID limit checks Ingo Molnar
2017-11-27 10:49 ` [PATCH 14/24] x86/mm: Put MMU-to-h/w ASID translation in one place Ingo Molnar
2017-11-27 10:49 ` [PATCH 15/24] x86/mm: Allow flushing for future ASID switches Ingo Molnar
2017-11-28 5:16 ` Andy Lutomirski
2017-11-28 7:32 ` Dave Hansen
2017-11-28 16:39 ` Peter Zijlstra
2017-11-28 16:48 ` Peter Zijlstra
2017-11-28 18:13 ` Dave Hansen
2017-11-28 19:05 ` Peter Zijlstra
2017-11-28 19:36 ` Peter Zijlstra
2017-11-28 20:34 ` Andy Lutomirski
2017-11-28 20:39 ` Peter Zijlstra
2017-11-28 20:45 ` Peter Zijlstra
2017-11-30 15:40 ` Peter Zijlstra
2017-11-30 15:42 ` Andy Lutomirski
2017-11-30 15:44 ` Peter Zijlstra
2017-11-30 15:51 ` Dave Hansen
2017-11-30 16:18 ` Peter Zijlstra
2017-11-30 18:44 ` Dave Hansen
2017-11-30 18:48 ` Andy Lutomirski
2017-11-30 18:53 ` Dave Hansen
2017-11-30 20:01 ` Peter Zijlstra
2017-11-30 21:51 ` Andy Lutomirski
2017-11-30 18:55 ` Peter Zijlstra
2017-11-30 19:00 ` Dave Hansen
2017-11-30 19:20 ` Peter Zijlstra
2017-11-27 10:49 ` [PATCH 16/24] x86/mm/kaiser: Use PCID feature to make user and kernel switches faster Ingo Molnar
2017-11-28 5:22 ` Andy Lutomirski
2017-11-28 7:52 ` Dave Hansen
2017-11-27 10:49 ` [PATCH 17/24] x86/mm/kaiser: Disable native VSYSCALL Ingo Molnar
2017-11-27 10:49 ` [PATCH 18/24] x86/mm/kaiser: Add Kconfig Ingo Molnar
2017-11-27 10:49 ` [PATCH 19/24] x86/mm/kaiser: Respect disabled CPU features Ingo Molnar
2017-11-27 10:49 ` [PATCH 20/24] x86/mm/kaiser: Simplify disabling of global pages Ingo Molnar
2017-11-27 10:49 ` [PATCH 21/24] x86/mm/dump_pagetables: Check Kaiser shadow page table for WX pages Ingo Molnar
2017-11-27 10:49 ` [PATCH 22/24] x86/mm/debug_pagetables: Allow dumping current pagetables Ingo Molnar
2017-11-27 10:49 ` [PATCH 23/24] x86/mm/kaiser: Add boot time disable switch Ingo Molnar
2017-11-27 10:49 ` [PATCH 24/24] x86/mm/kaiser: Use the other page_table_lock pattern Ingo Molnar
2017-11-27 13:51 ` [PATCH 00/24] x86/mm: Add KAISER support Borislav Petkov
2017-11-27 13:57 ` Thomas Gleixner
2017-11-27 13:59 ` Borislav Petkov
2017-11-27 14:03 ` Ingo Molnar
2017-11-27 14:08 ` Ingo Molnar
2017-11-27 19:43 ` Linus Torvalds
2017-11-27 20:01 ` Linus Torvalds
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