From: Andrew Morton <akpm@linux-foundation.org>
To: akpm@linux-foundation.org, arnd@arndb.de, bp@alien8.de,
catalin.marinas@arm.com, cl@linux.com, dan.j.williams@intel.com,
dave.hansen@linux.intel.com, david@redhat.com,
elena.reshetova@intel.com, guro@fb.com, hagen@jauu.net,
hpa@zytor.com, James.Bottomley@HansenPartnership.com,
jejb@linux.ibm.com, kirill@shutemov.name, linux-mm@kvack.org,
lkp@intel.com, luto@kernel.org, mark.rutland@arm.com,
mingo@redhat.com, mm-commits@vger.kernel.org,
mtk.manpages@gmail.com, palmer@dabbelt.com,
palmerdabbelt@google.com, paul.walmsley@sifive.com,
peterz@infradead.org, rick.p.edgecombe@intel.com,
rppt@linux.ibm.com, shakeelb@google.com, shuah@kernel.org,
tglx@linutronix.de, torvalds@linux-foundation.org,
tycho@tycho.ws, viro@zeniv.linux.org.uk, will@kernel.org,
willy@infradead.org
Subject: [patch 10/54] set_memory: allow querying whether set_direct_map_*() is actually enabled
Date: Wed, 07 Jul 2021 18:07:59 -0700 [thread overview]
Message-ID: <20210708010759.RkYzreOc1%akpm@linux-foundation.org> (raw)
In-Reply-To: <20210707175950.eceddb86c6c555555d4730e2@linux-foundation.org>
From: Mike Rapoport <rppt@linux.ibm.com>
Subject: set_memory: allow querying whether set_direct_map_*() is actually enabled
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.
[arnd@arndb.de: arm64: kfence: fix header inclusion ]
Link: https://lkml.kernel.org/r/20210518072034.31572-4-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: James Bottomley <James.Bottomley@HansenPartnership.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>
Cc: kernel test robot <lkp@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
arch/arm64/include/asm/Kbuild | 1 -
arch/arm64/include/asm/cacheflush.h | 6 ------
arch/arm64/include/asm/kfence.h | 2 +-
arch/arm64/include/asm/set_memory.h | 17 +++++++++++++++++
arch/arm64/kernel/machine_kexec.c | 1 +
arch/arm64/mm/mmu.c | 7 +++----
arch/arm64/mm/pageattr.c | 13 +++++++++----
include/linux/set_memory.h | 12 ++++++++++++
8 files changed, 43 insertions(+), 16 deletions(-)
--- a/arch/arm64/include/asm/cacheflush.h~set_memory-allow-querying-whether-set_direct_map_-is-actually-enabled
+++ a/arch/arm64/include/asm/cacheflush.h
@@ -144,12 +144,6 @@ static __always_inline void icache_inval
dsb(ish);
}
-int set_memory_valid(unsigned long addr, int numpages, int enable);
-
-int set_direct_map_invalid_noflush(struct page *page);
-int set_direct_map_default_noflush(struct page *page);
-bool kernel_page_present(struct page *page);
-
#include <asm-generic/cacheflush.h>
#endif /* __ASM_CACHEFLUSH_H */
--- a/arch/arm64/include/asm/Kbuild~set_memory-allow-querying-whether-set_direct_map_-is-actually-enabled
+++ a/arch/arm64/include/asm/Kbuild
@@ -3,7 +3,6 @@ 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
generated-y += cpucaps.h
--- a/arch/arm64/include/asm/kfence.h~set_memory-allow-querying-whether-set_direct_map_-is-actually-enabled
+++ a/arch/arm64/include/asm/kfence.h
@@ -8,7 +8,7 @@
#ifndef __ASM_KFENCE_H
#define __ASM_KFENCE_H
-#include <asm/cacheflush.h>
+#include <asm/set_memory.h>
static inline bool arch_kfence_init_pool(void) { return true; }
--- /dev/null
+++ a/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 set_direct_map_default_noflush(struct page *page);
+bool kernel_page_present(struct page *page);
+
+#endif /* _ASM_ARM64_SET_MEMORY_H */
--- a/arch/arm64/kernel/machine_kexec.c~set_memory-allow-querying-whether-set_direct_map_-is-actually-enabled
+++ a/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>
--- a/arch/arm64/mm/mmu.c~set_memory-allow-querying-whether-set_direct_map_-is-actually-enabled
+++ a/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>
@@ -515,8 +516,7 @@ static void __init map_mem(pgd_t *pgdp)
*/
BUILD_BUG_ON(pgd_index(direct_map_end - 1) == pgd_index(direct_map_end));
- if (rodata_full || crash_mem_map || debug_pagealloc_enabled() ||
- IS_ENABLED(CONFIG_KFENCE))
+ if (can_set_direct_map() || crash_mem_map || IS_ENABLED(CONFIG_KFENCE))
flags |= NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
/*
@@ -1489,8 +1489,7 @@ int arch_add_memory(int nid, u64 start,
* 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),
--- a/arch/arm64/mm/pageattr.c~set_memory-allow-querying-whether-set_direct_map_-is-actually-enabled
+++ a/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;
@@ -155,7 +160,7 @@ int set_direct_map_invalid_noflush(struc
.clear_mask = __pgprot(PTE_VALID),
};
- if (!debug_pagealloc_enabled() && !rodata_full)
+ if (!can_set_direct_map())
return 0;
return apply_to_page_range(&init_mm,
@@ -170,7 +175,7 @@ int set_direct_map_default_noflush(struc
.clear_mask = __pgprot(PTE_RDONLY),
};
- if (!debug_pagealloc_enabled() && !rodata_full)
+ if (!can_set_direct_map())
return 0;
return apply_to_page_range(&init_mm,
@@ -181,7 +186,7 @@ int set_direct_map_default_noflush(struc
#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);
@@ -206,7 +211,7 @@ bool kernel_page_present(struct page *pa
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);
--- a/include/linux/set_memory.h~set_memory-allow-querying-whether-set_direct_map_-is-actually-enabled
+++ a/include/linux/set_memory.h
@@ -28,7 +28,19 @@ static inline bool kernel_page_present(s
{
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)
_
next prev parent reply other threads:[~2021-07-08 1:08 UTC|newest]
Thread overview: 71+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-08 0:59 incoming Andrew Morton
2021-07-08 1:07 ` [patch 01/54] lib/test: fix spelling mistakes Andrew Morton
2021-07-08 1:07 ` [patch 02/54] lib: " Andrew Morton
2021-07-08 1:07 ` [patch 03/54] lib: fix spelling mistakes in header files Andrew Morton
2021-07-08 1:07 ` [patch 04/54] hexagon: handle {,SOFT}IRQENTRY_TEXT in linker script Andrew Morton
2021-07-08 1:07 ` [patch 05/54] hexagon: use common DISCARDS macro Andrew Morton
2021-07-08 1:07 ` [patch 06/54] hexagon: select ARCH_WANT_LD_ORPHAN_WARN Andrew Morton
2021-07-08 1:07 ` [patch 07/54] mm/slub: use stackdepot to save stack trace in objects Andrew Morton
2021-07-16 7:39 ` Christoph Hellwig
2021-07-16 8:57 ` Vlastimil Babka
2021-07-16 9:12 ` Christoph Hellwig
2021-07-16 20:12 ` Linus Torvalds
2021-07-16 22:37 ` Vlastimil Babka
2021-07-17 17:34 ` Randy Dunlap
2021-07-18 7:29 ` Vlastimil Babka
2021-07-18 14:17 ` Randy Dunlap
2021-07-08 1:07 ` [patch 08/54] mmap: make mlock_future_check() global Andrew Morton
2021-07-08 1:07 ` [patch 09/54] riscv/Kconfig: make direct map manipulation options depend on MMU Andrew Morton
2021-07-08 1:07 ` Andrew Morton [this message]
2021-07-08 1:08 ` [patch 11/54] mm: introduce memfd_secret system call to create "secret" memory areas Andrew Morton
2021-07-08 3:13 ` Linus Torvalds
2021-07-08 5:21 ` Mike Rapoport
2021-07-08 18:38 ` Linus Torvalds
2021-07-08 20:13 ` Hagen Paul Pfeifer
2021-07-09 15:44 ` Mike Rapoport
2021-07-08 1:08 ` [patch 12/54] PM: hibernate: disable when there are active secretmem users Andrew Morton
2021-07-08 3:15 ` Linus Torvalds
2021-07-08 5:30 ` Mike Rapoport
2021-07-08 1:08 ` [patch 13/54] arch, mm: wire up memfd_secret system call where relevant Andrew Morton
2021-07-08 1:08 ` [patch 14/54] secretmem: test: add basic selftest for memfd_secret(2) Andrew Morton
2021-07-08 1:08 ` [patch 15/54] mm: fix spelling mistakes in header files Andrew Morton
2021-07-08 1:08 ` [patch 16/54] mm: add setup_initial_init_mm() helper Andrew Morton
2021-07-08 1:08 ` [patch 17/54] arc: convert to setup_initial_init_mm() Andrew Morton
2021-07-08 1:08 ` [patch 18/54] arm: " Andrew Morton
2021-07-08 1:08 ` [patch 19/54] arm64: " Andrew Morton
2021-07-08 1:08 ` [patch 20/54] csky: " Andrew Morton
2021-07-08 1:08 ` [patch 21/54] h8300: " Andrew Morton
2021-07-08 1:08 ` [patch 22/54] m68k: " Andrew Morton
2021-07-08 1:08 ` [patch 23/54] nds32: " Andrew Morton
2021-07-08 1:08 ` [patch 24/54] nios2: " Andrew Morton
2021-07-08 1:08 ` [patch 25/54] openrisc: " Andrew Morton
2021-07-08 1:08 ` [patch 26/54] powerpc: " Andrew Morton
2021-07-08 4:46 ` Christophe Leroy
2021-07-08 1:08 ` [patch 27/54] riscv: " Andrew Morton
2021-07-08 1:08 ` [patch 28/54] s390: " Andrew Morton
2021-07-08 1:09 ` [patch 29/54] sh: " Andrew Morton
2021-07-08 1:09 ` [patch 30/54] x86: " Andrew Morton
2021-07-08 1:09 ` [patch 31/54] buildid: only consider GNU notes for build ID parsing Andrew Morton
2021-07-08 1:09 ` [patch 32/54] buildid: add API to parse build ID out of buffer Andrew Morton
2021-07-08 1:09 ` [patch 33/54] buildid: stash away kernels build ID on init Andrew Morton
2021-07-08 1:09 ` [patch 34/54] dump_stack: add vmlinux build ID to stack traces Andrew Morton
2021-07-08 1:09 ` [patch 35/54] module: add printk formats to add module build ID to stacktraces Andrew Morton
2021-07-08 1:09 ` [patch 36/54] arm64: stacktrace: use %pSb for backtrace printing Andrew Morton
2021-07-08 1:09 ` [patch 37/54] x86/dumpstack: use %pSb/%pBb " Andrew Morton
2021-07-08 1:09 ` [patch 38/54] scripts/decode_stacktrace.sh: support debuginfod Andrew Morton
2021-07-08 1:09 ` [patch 39/54] scripts/decode_stacktrace.sh: silence stderr messages from addr2line/nm Andrew Morton
2021-07-08 1:09 ` [patch 40/54] scripts/decode_stacktrace.sh: indicate 'auto' can be used for base path Andrew Morton
2021-07-08 1:09 ` [patch 41/54] buildid: mark some arguments const Andrew Morton
2021-07-08 1:09 ` [patch 42/54] buildid: fix kernel-doc notation Andrew Morton
2021-07-08 1:09 ` [patch 43/54] kdump: use vmlinux_build_id to simplify Andrew Morton
2021-07-08 1:09 ` [patch 44/54] mm: rename pud_page_vaddr to pud_pgtable and make it return pmd_t * Andrew Morton
2021-07-08 1:09 ` [patch 45/54] mm: rename p4d_page_vaddr to p4d_pgtable and make it return pud_t * Andrew Morton
2021-07-08 1:09 ` [patch 46/54] selftest/mremap_test: update the test to handle pagesize other than 4K Andrew Morton
2021-07-08 1:10 ` [patch 47/54] selftest/mremap_test: avoid crash with static build Andrew Morton
2021-07-08 1:10 ` [patch 48/54] mm/mremap: convert huge PUD move to separate helper Andrew Morton
2021-07-08 1:10 ` [patch 49/54] mm/mremap: don't enable optimized PUD move if page table levels is 2 Andrew Morton
2021-07-08 1:10 ` [patch 50/54] mm/mremap: use pmd/pud_poplulate to update page table entries Andrew Morton
2021-07-08 1:10 ` [patch 51/54] mm/mremap: hold the rmap lock in write mode when moving " Andrew Morton
2021-07-08 1:10 ` [patch 52/54] mm/mremap: allow arch runtime override Andrew Morton
2021-07-08 1:10 ` [patch 53/54] powerpc/book3s64/mm: update flush_tlb_range to flush page walk cache Andrew Morton
2021-07-08 1:10 ` [patch 54/54] powerpc/mm: enable HAVE_MOVE_PMD support Andrew Morton
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