linux-stable.git/arch/nios2/include/asm, branch linux-5.4.y

nios2: force update_mmu_cache on spurious tlb-permission--related pagefaults

2025-06-27T10:02:54+00:00

[ Upstream commit 2d8a3179ea035f9341b6a73e5ba4029fc67e983d ]

NIOS2 uses a software-managed TLB for virtual address translation. To
flush a cache line, the original mapping is replaced by one to physical
address 0x0 with no permissions (rwx mapped to 0) set. This can lead to
TLB-permission--related traps when such a nominally flushed entry is
encountered as a mapping for an otherwise valid virtual address within a
process (e.g. due to an MMU-PID-namespace rollover that previously
flushed the complete TLB including entries of existing, running
processes).

The default ptep_set_access_flags implementation from mm/pgtable-generic.c
only forces a TLB-update when the page-table entry has changed within the
page table:

	/*
	 * [...] We return whether the PTE actually changed, which in turn
	 * instructs the caller to do things like update__mmu_cache. [...]
	 */
	int ptep_set_access_flags(struct vm_area_struct *vma,
				  unsigned long address, pte_t *ptep,
				  pte_t entry, int dirty)
	{
		int changed = !pte_same(*ptep, entry);
		if (changed) {
			set_pte_at(vma->vm_mm, address, ptep, entry);
			flush_tlb_fix_spurious_fault(vma, address);
		}
		return changed;
	}

However, no cross-referencing with the TLB-state occurs, so the
flushing-induced pseudo entries that are responsible for the pagefault
in the first place are never pre-empted from TLB on this code path.

This commit fixes this behaviour by always requesting a TLB-update in
this part of the pagefault handling, fixing spurious page-faults on the
way. The handling is a straightforward port of the logic from the MIPS
architecture via an arch-specific ptep_set_access_flags function ported
from arch/mips/include/asm/pgtable.h.

Signed-off-by: Simon Schuster 
Signed-off-by: Andreas Oetken 
Signed-off-by: Dinh Nguyen 
Signed-off-by: Sasha Levin

nios2: add force_successful_syscall_return()

2022-08-25T09:18:28+00:00

commit fd0c153daad135d0ec1a53c5dbe6936a724d6ae1 upstream.

If we use the ancient SysV syscall ABI, we'd better have tell the
kernel how to claim that a negative return value is a success.
Use ->orig_r2 for that - it's inaccessible via ptrace, so it's
a fair game for changes and it's normally[*] non-negative on return
from syscall.  Set to -1; syscall is not going to be restart-worthy
by definition, so we won't interfere with that use either.

[*] the only exception is rt_sigreturn(), where we skip the entire
messing with r1/r2 anyway.

Fixes: 82ed08dd1b0e ("nios2: Exception handling")
Signed-off-by: Al Viro 
Signed-off-by: Dinh Nguyen 
Signed-off-by: Greg Kroah-Hartman

nios2: page fault et.al. are not restartable syscalls...

2022-08-25T09:18:27+00:00

commit 8535c239ac674f7ead0f2652932d35c52c4123b2 upstream.

make sure that ->orig_r2 is negative for everything except
the syscalls.

Fixes: 82ed08dd1b0e ("nios2: Exception handling")
Signed-off-by: Al Viro 
Signed-off-by: Dinh Nguyen 
Signed-off-by: Greg Kroah-Hartman

nios2: use fallback for random_get_entropy() instead of zero

2022-06-22T12:11:15+00:00

commit c04e72700f2293013dab40208e809369378f224c upstream.

In the event that random_get_entropy() can't access a cycle counter or
similar, falling back to returning 0 is really not the best we can do.
Instead, at least calling random_get_entropy_fallback() would be
preferable, because that always needs to return _something_, even
falling back to jiffies eventually. It's not as though
random_get_entropy_fallback() is super high precision or guaranteed to
be entropic, but basically anything that's not zero all the time is
better than returning zero all the time.

Cc: Thomas Gleixner 
Cc: Arnd Bergmann 
Acked-by: Dinh Nguyen 
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: Greg Kroah-Hartman

uaccess: fix nios2 and microblaze get_user_8()

2022-04-15T12:18:08+00:00

[ Upstream commit a97b693c3712f040c5802f32b2d685352e08cefa ]

These two architectures implement 8-byte get_user() through
a memcpy() into a four-byte variable, which won't fit.

Use a temporary 64-bit variable instead here, and use a double
cast the way that risc-v and openrisc do to avoid compile-time
warnings.

Fixes: 6a090e97972d ("arch/microblaze: support get_user() of size 8 bytes")
Fixes: 5ccc6af5e88e ("nios2: Memory management")
Reviewed-by: Christoph Hellwig 
Acked-by: Dinh Nguyen 
Signed-off-by: Arnd Bergmann 
Signed-off-by: Sasha Levin

NIOS2: irqflags: rename a redefined register name

2021-10-27T07:54:25+00:00

[ Upstream commit 4cce60f15c04d69eff6ffc539ab09137dbe15070 ]

Both arch/nios2/ and drivers/mmc/host/tmio_mmc.c define a macro
with the name "CTL_STATUS". Change the one in arch/nios2/ to be
"CTL_FSTATUS" (flags status) to eliminate the build warning.

In file included from ../drivers/mmc/host/tmio_mmc.c:22:
drivers/mmc/host/tmio_mmc.h:31: warning: "CTL_STATUS" redefined
   31 | #define CTL_STATUS 0x1c
arch/nios2/include/asm/registers.h:14: note: this is the location of the previous definition
   14 | #define CTL_STATUS      0

Fixes: b31ebd8055ea ("nios2: Nios2 registers")
Signed-off-by: Randy Dunlap 
Cc: Dinh Nguyen 
Signed-off-by: Dinh Nguyen 
Signed-off-by: Sasha Levin

mm: treewide: clarify pgtable_page_{ctor,dtor}() naming

2019-09-26T17:10:44+00:00

The naming of pgtable_page_{ctor,dtor}() seems to have confused a few
people, and until recently arm64 used these erroneously/pointlessly for
other levels of page table.

To make it incredibly clear that these only apply to the PTE level, and to
align with the naming of pgtable_pmd_page_{ctor,dtor}(), let's rename them
to pgtable_pte_page_{ctor,dtor}().

These changes were generated with the following shell script:

----
git grep -lw 'pgtable_page_.tor' | while read FILE; do
    sed -i '{s/pgtable_page_ctor/pgtable_pte_page_ctor/}' $FILE;
    sed -i '{s/pgtable_page_dtor/pgtable_pte_page_dtor/}' $FILE;
done
----

... with the documentation re-flowed to remain under 80 columns, and
whitespace fixed up in macros to keep backslashes aligned.

There should be no functional change as a result of this patch.

Link: http://lkml.kernel.org/r/20190722141133.3116-1-mark.rutland@arm.com
Signed-off-by: Mark Rutland 
Reviewed-by: Mike Rapoport 
Acked-by: Geert Uytterhoeven 	[m68k]
Cc: Anshuman Khandual 
Cc: Matthew Wilcox 
Cc: Michal Hocko 
Cc: Yu Zhao 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: consolidate pgtable_cache_init() and pgd_cache_init()

2019-09-24T22:54:09+00:00

Both pgtable_cache_init() and pgd_cache_init() are used to initialize kmem
cache for page table allocations on several architectures that do not use
PAGE_SIZE tables for one or more levels of the page table hierarchy.

Most architectures do not implement these functions and use __weak default
NOP implementation of pgd_cache_init().  Since there is no such default
for pgtable_cache_init(), its empty stub is duplicated among most
architectures.

Rename the definitions of pgd_cache_init() to pgtable_cache_init() and
drop empty stubs of pgtable_cache_init().

Link: http://lkml.kernel.org/r/1566457046-22637-1-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport 
Acked-by: Will Deacon 		[arm64]
Acked-by: Thomas Gleixner 	[x86]
Cc: Catalin Marinas 
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Cc: Matthew Wilcox 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: remove quicklist page table caches