kernel.git/arch/parisc/include, branch linux-6.4.y

parisc: Fix lightweight spinlock checks to not break futexes

2023-08-16T16:32:18Z

commit a0f4b7879f2e14986200747d1b545e5daac8c624 upstream. The lightweight spinlock checks verify that a spinlock has either value 0 (spinlock locked) and that not any other bits than in __ARCH_SPIN_LOCK_UNLOCKED_VAL is set. This breaks the current LWS code, which writes the address of the lock into the lock word to unlock it, which was an optimization to save one assembler instruction. Fix it by making spinlock_types.h accessible for asm code, change the LWS spinlock-unlocking code to write __ARCH_SPIN_LOCK_UNLOCKED_VAL into the lock word, and add some missing lightweight spinlock checks to the LWS path. Finally, make the spinlock checks dependend on DEBUG_KERNEL. Noticed-by: John David Anglin Signed-off-by: Helge Deller Tested-by: John David Anglin Cc: stable@vger.kernel.org # v6.4+ Fixes: 15e64ef6520e ("parisc: Add lightweight spinlock checks") Signed-off-by: Greg Kroah-Hartman

init: Remove check_bugs() leftovers

2023-08-08T18:04:49Z

commit 61235b24b9cb37c13fcad5b9596d59a1afdcec30 upstream Everything is converted over to arch_cpu_finalize_init(). Remove the check_bugs() leftovers including the empty stubs in asm-generic, alpha, parisc, powerpc and xtensa. Signed-off-by: Thomas Gleixner Reviewed-by: Richard Henderson Link: https://lore.kernel.org/r/20230613224545.553215951@linutronix.de Signed-off-by: Daniel Sneddon Signed-off-by: Greg Kroah-Hartman

parisc: Delete redundant register definitions in

2023-06-17T04:48:11Z

We define sp and ipsw in using ".reg", and when using current binutils (snapshot 2.40.50.20230611) the definitions in using "=" conflict with those: arch/parisc/include/asm/assembly.h: Assembler messages: arch/parisc/include/asm/assembly.h:93: Error: symbol `sp' is already defined arch/parisc/include/asm/assembly.h:95: Error: symbol `ipsw' is already defined Delete the duplicate definitions in . Also delete the definition of gp, which isn't used anywhere. Signed-off-by: Ben Hutchings Cc: stable@vger.kernel.org # v6.0+ Signed-off-by: Helge Deller

parisc: Fix flush_dcache_page() for usage from irq context

2023-05-24T17:03:49Z

Since at least kernel 6.1, flush_dcache_page() is called with IRQs disabled, e.g. from aio_complete(). But the current implementation for flush_dcache_page() on parisc unintentionally re-enables IRQs, which may lead to deadlocks. Fix it by using xa_lock_irqsave() and xa_unlock_irqrestore() for the flush_dcache_mmap_*lock() macros instead. Cc: linux-parisc@vger.kernel.org Cc: stable@kernel.org # 5.18+ Signed-off-by: Helge Deller

parisc: Add lightweight spinlock checks

2023-05-24T12:23:07Z

Add a lightweight spinlock check which uses only two instructions per spinlock call. It detects if a spinlock has been trashed by some memory corruption and then halts the kernel. It will not detect uninitialized spinlocks, for which CONFIG_DEBUG_SPINLOCK needs to be enabled. This lightweight spinlock check shouldn't influence runtime, so it's safe to enable it by default. The __ARCH_SPIN_LOCK_UNLOCKED_VAL constant has been choosen small enough to be able to be loaded by one LDI assembler statement. Signed-off-by: Helge Deller

parisc: Fix encoding of swp_entry due to added SWP_EXCLUSIVE flag

2023-05-14T00:04:27Z

Fix the __swp_offset() and __swp_entry() macros due to commit 6d239fc78c0b ("parisc/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE") which introduced the SWP_EXCLUSIVE flag by reusing the _PAGE_ACCESSED flag. Reported-by: Christoph Biedl Tested-by: Christoph Biedl Reviewed-by: David Hildenbrand Signed-off-by: Helge Deller Fixes: 6d239fc78c0b ("parisc/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE") Cc: # v6.3+

Merge tag 'locking-core-2023-05-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2023-05-05T19:56:55Z

Pull locking updates from Ingo Molnar: - Introduce local{,64}_try_cmpxchg() - a slightly more optimal primitive, which will be used in perf events ring-buffer code - Simplify/modify rwsems on PREEMPT_RT, to address writer starvation - Misc cleanups/fixes * tag 'locking-core-2023-05-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: locking/atomic: Correct (cmp)xchg() instrumentation locking/x86: Define arch_try_cmpxchg_local() locking/arch: Wire up local_try_cmpxchg() locking/generic: Wire up local{,64}_try_cmpxchg() locking/atomic: Add generic try_cmpxchg{,64}_local() support locking/rwbase: Mitigate indefinite writer starvation locking/arch: Rename all internal __xchg() names to __arch_xchg()

parisc: Drop HP-UX constants and structs from grfioctl.h

2023-05-03T15:43:26Z

Signed-off-by: Helge Deller

parisc: Replace regular spinlock with spin_trylock on panic path

2023-05-03T15:43:26Z

The panic notifiers' callbacks execute in an atomic context, with interrupts/preemption disabled, and all CPUs not running the panic function are off, so it's very dangerous to wait on a regular spinlock, there's a risk of deadlock. Refactor the panic notifier of parisc/power driver to make use of spin_trylock - for that, we've added a second version of the soft-power function. Also, some comments were reorganized and trailing white spaces, useless header inclusion and blank lines were removed. Cc: "James E.J. Bottomley" Cc: Jeroen Roovers Acked-by: Helge Deller # parisc Signed-off-by: Guilherme G. Piccoli Signed-off-by: Helge Deller

parisc: Limit amount of kgdb breakpoints on parisc

2023-05-03T15:41:21Z

kgdb is rarely used and 40 breakpoints seems enough to debug parisc specific bugs. Signed-off-by: Helge Deller