From: Mike Rapoport <rppt@kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>,
Andy Lutomirski <luto@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
Borislav Petkov <bp@alien8.de>,
Catalin Marinas <catalin.marinas@arm.com>,
Christopher Lameter <cl@linux.com>,
Dan Williams <dan.j.williams@intel.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
David Hildenbrand <david@redhat.com>,
Elena Reshetova <elena.reshetova@intel.com>,
"H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>,
James Bottomley <jejb@linux.ibm.com>,
"Kirill A. Shutemov" <kirill@shutemov.name>,
Matthew Wilcox <willy@infradead.org>,
Mark Rutland <mark.rutland@arm.com>,
Mike Rapoport <rppt@linux.ibm.com>,
Mike Rapoport <rppt@kernel.org>,
Michael Kerrisk <mtk.manpages@gmail.com>,
Palmer Dabbelt <palmer@dabbelt.com>,
Paul Walmsley <paul.walmsley@sifive.com>,
Peter Zijlstra <peterz@infradead.org>,
Rick Edgecombe <rick.p.edgecombe@intel.com>,
Roman Gushchin <guro@fb.com>, Shakeel Butt <shakeelb@google.com>,
Shuah Khan <shuah@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Tycho Andersen <tycho@tycho.ws>, Will Deacon <will@kernel.org>,
linux-api@vger.kernel.org, linux-arch@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
linux-nvdimm@lists.01.org, linux-riscv@lists.infradead.org,
x86@kernel.org, Hagen Paul Pfeifer <hagen@jauu.net>,
Palmer Dabbelt <palmerdabbelt@google.com>
Subject: [PATCH v16 05/11] set_memory: allow querying whether set_direct_map_*() is actually enabled
Date: Thu, 21 Jan 2021 14:27:17 +0200 [thread overview]
Message-ID: <20210121122723.3446-6-rppt@kernel.org> (raw)
In-Reply-To: <20210121122723.3446-1-rppt@kernel.org>
From: Mike Rapoport <rppt@linux.ibm.com>
On arm64, set_direct_map_*() functions may return 0 without actually
changing the linear map. This behaviour can be controlled using kernel
parameters, so we need a way to determine at runtime whether calls to
set_direct_map_invalid_noflush() and set_direct_map_default_noflush() have
any effect.
Extend set_memory API with can_set_direct_map() function that allows
checking if calling set_direct_map_*() will actually change the page table,
replace several occurrences of open coded checks in arm64 with the new
function and provide a generic stub for architectures that always modify
page tables upon calls to set_direct_map APIs.
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christopher Lameter <cl@linux.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Elena Reshetova <elena.reshetova@intel.com>
Cc: Hagen Paul Pfeifer <hagen@jauu.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Palmer Dabbelt <palmerdabbelt@google.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tycho Andersen <tycho@tycho.ws>
Cc: Will Deacon <will@kernel.org>
---
arch/arm64/include/asm/Kbuild | 1 -
arch/arm64/include/asm/cacheflush.h | 6 ------
arch/arm64/include/asm/set_memory.h | 17 +++++++++++++++++
arch/arm64/kernel/machine_kexec.c | 1 +
arch/arm64/mm/mmu.c | 6 +++---
arch/arm64/mm/pageattr.c | 13 +++++++++----
include/linux/set_memory.h | 12 ++++++++++++
7 files changed, 42 insertions(+), 14 deletions(-)
create mode 100644 arch/arm64/include/asm/set_memory.h
diff --git a/arch/arm64/include/asm/Kbuild b/arch/arm64/include/asm/Kbuild
index 07ac208edc89..73aa25843f65 100644
--- a/arch/arm64/include/asm/Kbuild
+++ b/arch/arm64/include/asm/Kbuild
@@ -3,5 +3,4 @@ generic-y += early_ioremap.h
generic-y += mcs_spinlock.h
generic-y += qrwlock.h
generic-y += qspinlock.h
-generic-y += set_memory.h
generic-y += user.h
diff --git a/arch/arm64/include/asm/cacheflush.h b/arch/arm64/include/asm/cacheflush.h
index d3598419a284..b1bdf83a73db 100644
--- a/arch/arm64/include/asm/cacheflush.h
+++ b/arch/arm64/include/asm/cacheflush.h
@@ -136,12 +136,6 @@ static __always_inline void __flush_icache_all(void)
dsb(ish);
}
-int set_memory_valid(unsigned long addr, int numpages, int enable);
-
-int set_direct_map_invalid_noflush(struct page *page, int numpages);
-int set_direct_map_default_noflush(struct page *page, int numpages);
-bool kernel_page_present(struct page *page);
-
#include <asm-generic/cacheflush.h>
#endif /* __ASM_CACHEFLUSH_H */
diff --git a/arch/arm64/include/asm/set_memory.h b/arch/arm64/include/asm/set_memory.h
new file mode 100644
index 000000000000..ecb6b0f449ab
--- /dev/null
+++ b/arch/arm64/include/asm/set_memory.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _ASM_ARM64_SET_MEMORY_H
+#define _ASM_ARM64_SET_MEMORY_H
+
+#include <asm-generic/set_memory.h>
+
+bool can_set_direct_map(void);
+#define can_set_direct_map can_set_direct_map
+
+int set_memory_valid(unsigned long addr, int numpages, int enable);
+
+int set_direct_map_invalid_noflush(struct page *page, int numpages);
+int set_direct_map_default_noflush(struct page *page, int numpages);
+bool kernel_page_present(struct page *page);
+
+#endif /* _ASM_ARM64_SET_MEMORY_H */
diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c
index a0b144cfaea7..0cbc50c4fa5a 100644
--- a/arch/arm64/kernel/machine_kexec.c
+++ b/arch/arm64/kernel/machine_kexec.c
@@ -11,6 +11,7 @@
#include <linux/kernel.h>
#include <linux/kexec.h>
#include <linux/page-flags.h>
+#include <linux/set_memory.h>
#include <linux/smp.h>
#include <asm/cacheflush.h>
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 30c6dd02e706..79604049fff5 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -22,6 +22,7 @@
#include <linux/io.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
+#include <linux/set_memory.h>
#include <asm/barrier.h>
#include <asm/cputype.h>
@@ -492,7 +493,7 @@ static void __init map_mem(pgd_t *pgdp)
int flags = 0;
u64 i;
- if (rodata_full || crash_mem_map || debug_pagealloc_enabled())
+ if (can_set_direct_map() || crash_mem_map)
flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
/*
@@ -1468,8 +1469,7 @@ int arch_add_memory(int nid, u64 start, u64 size,
* KFENCE requires linear map to be mapped at page granularity, so that
* it is possible to protect/unprotect single pages in the KFENCE pool.
*/
- if (rodata_full || debug_pagealloc_enabled() ||
- IS_ENABLED(CONFIG_KFENCE))
+ if (can_set_direct_map() || IS_ENABLED(CONFIG_KFENCE))
flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
__create_pgd_mapping(swapper_pg_dir, start, __phys_to_virt(start),
diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
index b53ef37bf95a..d505172265b0 100644
--- a/arch/arm64/mm/pageattr.c
+++ b/arch/arm64/mm/pageattr.c
@@ -19,6 +19,11 @@ struct page_change_data {
bool rodata_full __ro_after_init = IS_ENABLED(CONFIG_RODATA_FULL_DEFAULT_ENABLED);
+bool can_set_direct_map(void)
+{
+ return rodata_full || debug_pagealloc_enabled();
+}
+
static int change_page_range(pte_t *ptep, unsigned long addr, void *data)
{
struct page_change_data *cdata = data;
@@ -156,7 +161,7 @@ int set_direct_map_invalid_noflush(struct page *page, int numpages)
};
unsigned long size = PAGE_SIZE * numpages;
- if (!debug_pagealloc_enabled() && !rodata_full)
+ if (!can_set_direct_map())
return 0;
return apply_to_page_range(&init_mm,
@@ -172,7 +177,7 @@ int set_direct_map_default_noflush(struct page *page, int numpages)
};
unsigned long size = PAGE_SIZE * numpages;
- if (!debug_pagealloc_enabled() && !rodata_full)
+ if (!can_set_direct_map())
return 0;
return apply_to_page_range(&init_mm,
@@ -183,7 +188,7 @@ int set_direct_map_default_noflush(struct page *page, int numpages)
#ifdef CONFIG_DEBUG_PAGEALLOC
void __kernel_map_pages(struct page *page, int numpages, int enable)
{
- if (!debug_pagealloc_enabled() && !rodata_full)
+ if (!can_set_direct_map())
return;
set_memory_valid((unsigned long)page_address(page), numpages, enable);
@@ -208,7 +213,7 @@ bool kernel_page_present(struct page *page)
pte_t *ptep;
unsigned long addr = (unsigned long)page_address(page);
- if (!debug_pagealloc_enabled() && !rodata_full)
+ if (!can_set_direct_map())
return true;
pgdp = pgd_offset_k(addr);
diff --git a/include/linux/set_memory.h b/include/linux/set_memory.h
index c650f82db813..7b4b6626032d 100644
--- a/include/linux/set_memory.h
+++ b/include/linux/set_memory.h
@@ -28,7 +28,19 @@ static inline bool kernel_page_present(struct page *page)
{
return true;
}
+#else /* CONFIG_ARCH_HAS_SET_DIRECT_MAP */
+/*
+ * Some architectures, e.g. ARM64 can disable direct map modifications at
+ * boot time. Let them overrive this query.
+ */
+#ifndef can_set_direct_map
+static inline bool can_set_direct_map(void)
+{
+ return true;
+}
+#define can_set_direct_map can_set_direct_map
#endif
+#endif /* CONFIG_ARCH_HAS_SET_DIRECT_MAP */
#ifndef set_mce_nospec
static inline int set_mce_nospec(unsigned long pfn, bool unmap)
--
2.28.0
next prev parent reply other threads:[~2021-01-21 12:28 UTC|newest]
Thread overview: 78+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-21 12:27 [PATCH v16 00/11] mm: introduce memfd_secret system call to create "secret" memory areas Mike Rapoport
2021-01-21 12:27 ` [PATCH v16 01/11] mm: add definition of PMD_PAGE_ORDER Mike Rapoport
2021-01-21 12:27 ` [PATCH v16 02/11] mmap: make mlock_future_check() global Mike Rapoport
2021-01-21 12:27 ` [PATCH v16 03/11] riscv/Kconfig: make direct map manipulation options depend on MMU Mike Rapoport
2021-01-21 12:27 ` [PATCH v16 04/11] set_memory: allow set_direct_map_*_noflush() for multiple pages Mike Rapoport
2021-01-21 12:27 ` Mike Rapoport [this message]
2021-01-21 12:27 ` [PATCH v16 06/11] mm: introduce memfd_secret system call to create "secret" memory areas Mike Rapoport
2021-01-25 17:01 ` Michal Hocko
2021-01-25 21:36 ` Mike Rapoport
2021-01-26 7:16 ` Michal Hocko
2021-01-26 8:33 ` Mike Rapoport
2021-01-26 9:00 ` Michal Hocko
2021-01-26 9:20 ` Mike Rapoport
2021-01-26 9:49 ` Michal Hocko
2021-01-26 9:53 ` David Hildenbrand
2021-01-26 10:19 ` Michal Hocko
2021-01-26 9:20 ` Michal Hocko
2021-02-03 12:15 ` Michal Hocko
2021-02-04 11:34 ` Mike Rapoport
2021-01-21 12:27 ` [PATCH v16 07/11] secretmem: use PMD-size pages to amortize direct map fragmentation Mike Rapoport
2021-01-26 11:46 ` Michal Hocko
2021-01-26 11:56 ` David Hildenbrand
2021-01-26 12:08 ` Michal Hocko
2021-01-28 9:22 ` Mike Rapoport
2021-01-28 13:01 ` Michal Hocko
2021-01-28 13:28 ` Christoph Lameter
2021-01-28 13:49 ` Michal Hocko
2021-01-28 15:56 ` Christoph Lameter
2021-01-28 16:23 ` Michal Hocko
2021-01-28 15:28 ` James Bottomley
2021-01-29 7:03 ` Mike Rapoport
2021-01-28 21:05 ` James Bottomley
2021-01-29 7:53 ` Michal Hocko
2021-01-29 8:23 ` Michal Hocko
2021-02-01 16:56 ` James Bottomley
2021-02-02 9:35 ` Michal Hocko
2021-02-02 12:48 ` Mike Rapoport
2021-02-02 13:14 ` David Hildenbrand
2021-02-02 13:32 ` Michal Hocko
2021-02-02 14:12 ` David Hildenbrand
2021-02-02 14:22 ` Michal Hocko
2021-02-02 14:26 ` David Hildenbrand
2021-02-02 14:32 ` Michal Hocko
2021-02-02 14:34 ` David Hildenbrand
2021-02-02 18:15 ` Mike Rapoport
2021-02-02 18:55 ` James Bottomley
2021-02-03 12:09 ` Michal Hocko
2021-02-04 11:31 ` Mike Rapoport
2021-02-02 13:27 ` Michal Hocko
2021-02-02 19:10 ` Mike Rapoport
2021-02-03 9:12 ` Michal Hocko
2021-02-04 9:58 ` Mike Rapoport
2021-02-04 13:02 ` Michal Hocko
2021-01-29 7:21 ` Mike Rapoport
2021-01-29 8:51 ` Michal Hocko
2021-02-02 14:42 ` David Hildenbrand
2021-01-21 12:27 ` [PATCH v16 08/11] secretmem: add memcg accounting Mike Rapoport
2021-01-25 16:17 ` Matthew Wilcox
2021-01-25 17:18 ` Shakeel Butt
2021-01-25 21:35 ` Mike Rapoport
2021-01-28 15:07 ` Shakeel Butt
2021-01-25 16:54 ` Michal Hocko
2021-01-25 21:38 ` Mike Rapoport
2021-01-26 7:31 ` Michal Hocko
2021-01-26 8:56 ` Mike Rapoport
2021-01-26 9:15 ` Michal Hocko
2021-01-26 14:48 ` Matthew Wilcox
2021-01-26 15:05 ` Michal Hocko
2021-01-27 18:42 ` Roman Gushchin
2021-01-28 7:58 ` Michal Hocko
2021-01-28 14:05 ` Shakeel Butt
2021-01-28 14:22 ` Michal Hocko
2021-01-28 14:57 ` Shakeel Butt
2021-01-21 12:27 ` [PATCH v16 09/11] PM: hibernate: disable when there are active secretmem users Mike Rapoport
2021-01-21 12:27 ` [PATCH v16 10/11] arch, mm: wire up memfd_secret system call where relevant Mike Rapoport
2021-01-25 18:18 ` Catalin Marinas
2021-01-21 12:27 ` [PATCH v16 11/11] secretmem: test: add basic selftest for memfd_secret(2) Mike Rapoport
2021-01-21 22:18 ` [PATCH v16 00/11] mm: introduce memfd_secret system call to create "secret" memory areas Andrew Morton
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