x86/mm/cpa: Add set_direct_map_*() functions

Add two new functions set_direct_map_default_noflush() and
set_direct_map_invalid_noflush() for setting the direct map alias for the
page to its default valid permissions and to an invalid state that cannot
be cached in a TLB, respectively. These functions do not flush the TLB.

Note, __kernel_map_pages() does something similar but flushes the TLB and
doesn't reset the permission bits to default on all architectures.

Also add an ARCH config ARCH_HAS_SET_DIRECT_MAP for specifying whether
these have an actual implementation or a default empty one.

Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <akpm@linux-foundation.org>
Cc: <ard.biesheuvel@linaro.org>
Cc: <deneen.t.dock@intel.com>
Cc: <kernel-hardening@lists.openwall.com>
Cc: <kristen@linux.intel.com>
Cc: <linux_dti@icloud.com>
Cc: <will.deacon@arm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190426001143.4983-15-namit@vmware.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Rick Edgecombe 2019-04-25 17:11:34 -07:00 committed by Ingo Molnar
parent 0a203df5cf
commit d253ca0c38
5 changed files with 30 additions and 3 deletions

View File

@ -249,6 +249,10 @@ config ARCH_HAS_FORTIFY_SOURCE
config ARCH_HAS_SET_MEMORY
bool
# Select if arch has all set_direct_map_invalid/default() functions
config ARCH_HAS_SET_DIRECT_MAP
bool
# Select if arch init_task must go in the __init_task_data section
config ARCH_TASK_STRUCT_ON_STACK
bool

View File

@ -65,6 +65,7 @@ config X86
select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE
select ARCH_HAS_SET_MEMORY
select ARCH_HAS_SET_DIRECT_MAP
select ARCH_HAS_STRICT_KERNEL_RWX
select ARCH_HAS_STRICT_MODULE_RWX
select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE

View File

@ -85,6 +85,9 @@ int set_pages_nx(struct page *page, int numpages);
int set_pages_ro(struct page *page, int numpages);
int set_pages_rw(struct page *page, int numpages);
int set_direct_map_invalid_noflush(struct page *page);
int set_direct_map_default_noflush(struct page *page);
extern int kernel_set_to_readonly;
void set_kernel_text_rw(void);
void set_kernel_text_ro(void);

View File

@ -2209,8 +2209,6 @@ int set_pages_rw(struct page *page, int numpages)
return set_memory_rw(addr, numpages);
}
#ifdef CONFIG_DEBUG_PAGEALLOC
static int __set_pages_p(struct page *page, int numpages)
{
unsigned long tempaddr = (unsigned long) page_address(page);
@ -2249,6 +2247,17 @@ static int __set_pages_np(struct page *page, int numpages)
return __change_page_attr_set_clr(&cpa, 0);
}
int set_direct_map_invalid_noflush(struct page *page)
{
return __set_pages_np(page, 1);
}
int set_direct_map_default_noflush(struct page *page)
{
return __set_pages_p(page, 1);
}
#ifdef CONFIG_DEBUG_PAGEALLOC
void __kernel_map_pages(struct page *page, int numpages, int enable)
{
if (PageHighMem(page))
@ -2282,7 +2291,6 @@ void __kernel_map_pages(struct page *page, int numpages, int enable)
}
#ifdef CONFIG_HIBERNATION
bool kernel_page_present(struct page *page)
{
unsigned int level;

View File

@ -17,6 +17,17 @@ static inline int set_memory_x(unsigned long addr, int numpages) { return 0; }
static inline int set_memory_nx(unsigned long addr, int numpages) { return 0; }
#endif
#ifndef CONFIG_ARCH_HAS_SET_DIRECT_MAP
static inline int set_direct_map_invalid_noflush(struct page *page)
{
return 0;
}
static inline int set_direct_map_default_noflush(struct page *page)
{
return 0;
}
#endif
#ifndef set_mce_nospec
static inline int set_mce_nospec(unsigned long pfn)
{