kernel.git/arch/parisc/kernel/syscall.S, branch linux-5.16.y

parisc: Correct completer in lws start

2021-12-21T20:07:39Z

The completer in the "or,ev %r1,%r30,%r30" instruction is reversed, so we are not clipping the LWS number when we are called from a 32-bit process (W=0). We need to nulify the following depdi instruction when the least-significant bit of %r30 is 1. If the %r20 register is not clipped, a user process could perform a LWS call that would branch to an undefined location in the kernel and potentially crash the machine. Signed-off-by: John David Anglin Cc: stable@vger.kernel.org # 4.19+ Signed-off-by: Helge Deller

parisc: Fix extraction of hash lock bits in syscall.S

2021-11-22T06:37:31Z

The extru instruction leaves the most significant 32 bits of the target register in an undefined state on PA 2.0 systems. If any of these bits are nonzero, this will break the calculation of the lock pointer. Fix by using extrd,u instruction via extru_safe macro on 64-bit kernels. Signed-off-by: John David Anglin Signed-off-by: Helge Deller

parisc: Don't disable interrupts in cmpxchg and futex operations

2021-11-04T10:21:20Z

I no longer think interrupts can be disabled in the futex and cmpxchg operations because of COW breaks. This not ideal but I suspect it's the best we can do. For the cmpxchg operations in syscall.S, we rely on the code to not schedule off the gateway page. For the futex, I added code to disable preemption. So far, I haven't seen the warnings with the attached change but the change is only lightly tested. Signed-off-by: Dave Anglin Signed-off-by: Helge Deller

parisc: Use PRIV_USER in syscall.S

2021-11-01T06:36:00Z

Signed-off-by: Helge Deller

parisc: Move thread_info into task struct

2021-11-01T06:35:59Z

This implements the CONFIG_THREAD_INFO_IN_TASK option. With this change: - before thread_info was part of the stack and located at the beginning of the stack - now the thread_info struct is moved and located inside the task_struct structure - the stack is allocated and handled like the major other platforms - drop the cpu field of thread_info and use instead the one in task_struct Signed-off-by: Helge Deller Signed-off-by: Sven Schnelle

parisc: syscalls: switch to generic syscalltbl.sh

2021-04-27T07:43:56Z

Many architectures duplicate similar shell scripts. This commit converts parisc to use scripts/syscalltbl.sh. This also unifies syscall_table_64.h and syscall_table_c32.h. Signed-off-by: Masahiro Yamada Acked-by: Helge Deller Signed-off-by: Helge Deller

parisc: Switch to more fine grained lws locks

2020-10-15T06:10:39Z

Increase the number of lws locks to 256 entries (instead of 16) and choose lock entry based on bits 3-11 (instead of 4-7) of the relevant address. With this change we archieve more fine-grained locking in futex syscalls and thus reduce the number of possible stalls. Signed-off-by: John David Anglin Signed-off-by: Helge Deller

Revert "parisc: Revert "Release spinlocks using ordered store""

2020-07-28T16:56:14Z

This reverts commit 86d4d068df573a8c2105554624796c086d6bec3d. Signed-off-by: Helge Deller Cc: # v5.0+

Revert "parisc: Use ldcw instruction for SMP spinlock release barrier"

2020-07-28T16:54:40Z

This reverts commit 9e5c602186a692a7e848c0da17aed40f49d30519. No need to use the ldcw instruction as SMP spinlock release barrier. Revert it to gain back speed again. Signed-off-by: Helge Deller Cc: # v5.2+

Revert "parisc: Drop LDCW barrier in CAS code when running UP"

2020-07-28T16:52:58Z

This reverts commit e6eb5fe9123f05dcbf339ae5c0b6d32fcc0685d5. We need to optimize it differently. A follow up patch will correct it. Signed-off-by: Helge Deller Cc: # v5.2+