linux.git/arch/alpha/kernel/entry.S, branch v6.6.131 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git alpha: replace hardcoded stack offsets with autogenerated ones 2025-02-21T12:57:27+00:00 Ivan Kokshaysky ink@unseen.parts 2025-02-04T22:35:22+00:00 fd0d07cb8b4792668487201956044ea045e72fef commit 77b823fa619f97d16409ca37ad4f7936e28c5f83 upstream. This allows the assembly in entry.S to automatically keep in sync with changes in the stack layout (struct pt_regs and struct switch_stack). Cc: stable@vger.kernel.org Tested-by: Maciej W. Rozycki <macro@orcam.me.uk> Tested-by: Matt Turner <mattst88@gmail.com> Reviewed-by: Maciej W. Rozycki <macro@orcam.me.uk> Signed-off-by: Ivan Kokshaysky <ink@unseen.parts> Signed-off-by: Matt Turner <mattst88@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 77b823fa619f97d16409ca37ad4f7936e28c5f83 upstream.

This allows the assembly in entry.S to automatically keep in sync with
changes in the stack layout (struct pt_regs and struct switch_stack).

Cc: stable@vger.kernel.org
Tested-by: Maciej W. Rozycki <macro@orcam.me.uk>
Tested-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Ivan Kokshaysky <ink@unseen.parts>
Signed-off-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alpha: align stack for page fault and user unaligned trap handlers 2025-02-21T12:57:18+00:00 Ivan Kokshaysky ink@unseen.parts 2025-02-04T22:35:24+00:00 0f4573f8fe00d968405ebe1ee58aa277bc5794d1 commit 3b35a171060f846b08b48646b38c30b5d57d17ff upstream. do_page_fault() and do_entUna() are special because they use non-standard stack frame layout. Fix them manually. Cc: stable@vger.kernel.org Tested-by: Maciej W. Rozycki <macro@orcam.me.uk> Tested-by: Magnus Lindholm <linmag7@gmail.com> Tested-by: Matt Turner <mattst88@gmail.com> Reviewed-by: Maciej W. Rozycki <macro@orcam.me.uk> Suggested-by: Maciej W. Rozycki <macro@orcam.me.uk> Signed-off-by: Ivan Kokshaysky <ink@unseen.parts> Signed-off-by: Matt Turner <mattst88@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 3b35a171060f846b08b48646b38c30b5d57d17ff upstream.

do_page_fault() and do_entUna() are special because they use
non-standard stack frame layout. Fix them manually.

Cc: stable@vger.kernel.org
Tested-by: Maciej W. Rozycki <macro@orcam.me.uk>
Tested-by: Magnus Lindholm <linmag7@gmail.com>
Tested-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Maciej W. Rozycki <macro@orcam.me.uk>
Suggested-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Ivan Kokshaysky <ink@unseen.parts>
Signed-off-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alpha: lazy FPU switching 2023-02-25T04:14:22+00:00 Al Viro viro@zeniv.linux.org.uk 2022-09-02T01:50:12+00:00 050966666047b5013fe44944cef9e9605bdf6cfe On each context switch we save the FPU registers on stack of old process and restore FPU registers from the stack of new one. That allows us to avoid doing that each time we enter/leave the kernel mode; however, that can get suboptimal in some cases. For one thing, we don't need to bother saving anything for kernel threads. For another, if between entering and leaving the kernel a thread gives CPU up more than once, it will do useless work, saving the same values every time, only to discard the saved copy as soon as it returns from switch_to(). Alternative solution: * move the array we save into from switch_stack to thread_info * have a (thread-synchronous) flag set when we save them * have another flag set when they should be restored on return to userland. * do *NOT* save/restore them in do_switch_stack()/undo_switch_stack(). * restore on the exit to user mode if the restore flag had been set. Clear both flags. * on context switch, entry to fork/clone/vfork, before entry into do_signal() and on entry into straced syscall save the registers and set the 'saved' flag unless it had been already set. * on context switch set the 'restore' flag as well. * have copy_thread() set both flags for child, so the registers would be restored once the child returns to userland. * use the saved data in setup_sigcontext(); have restore_sigcontext() set both flags and copy from sigframe to save area. * teach ptrace to look for FPU registers in thread_info instead of switch_stack. * teach isolated accesses to FPU registers (rdfpcr, wrfpcr, etc.) to check the 'saved' flag (under preempt_disable()) and work with the save area if it's been set; if 'saved' flag is found upon write access, set 'restore' flag as well. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Matt Turner <mattst88@gmail.com> 
	On each context switch we save the FPU registers on stack
of old process and restore FPU registers from the stack of new one.
That allows us to avoid doing that each time we enter/leave the
kernel mode; however, that can get suboptimal in some cases.

	For one thing, we don't need to bother saving anything
for kernel threads.  For another, if between entering and leaving
the kernel a thread gives CPU up more than once, it will do
useless work, saving the same values every time, only to discard
the saved copy as soon as it returns from switch_to().

	Alternative solution:

* move the array we save into from switch_stack to thread_info
* have a (thread-synchronous) flag set when we save them
* have another flag set when they should be restored on return to userland.
* do *NOT* save/restore them in do_switch_stack()/undo_switch_stack().
* restore on the exit to user mode if the restore flag had
been set.  Clear both flags.
* on context switch, entry to fork/clone/vfork, before entry into do_signal()
and on entry into straced syscall save the registers and set the 'saved' flag
unless it had been already set.
* on context switch set the 'restore' flag as well.
* have copy_thread() set both flags for child, so the registers would be
restored once the child returns to userland.
* use the saved data in setup_sigcontext(); have restore_sigcontext() set both flags
and copy from sigframe to save area.
* teach ptrace to look for FPU registers in thread_info instead of
switch_stack.
* teach isolated accesses to FPU registers (rdfpcr, wrfpcr, etc.)
to check the 'saved' flag (under preempt_disable()) and work with the save area
if it's been set; if 'saved' flag is found upon write access, set 'restore' flag
as well.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Matt Turner <mattst88@gmail.com>
alpha: replace NR_SYSCALLS by NR_syscalls 2023-02-14T17:37:17+00:00 Yang Yang yang.yang29@zte.com.cn 2022-03-29T02:57:38+00:00 d6e595792fb6c02c220bf68b50cf7649b1f05e15 Reference to other arch likes x86_64 or arm64 to do this replacement. To solve compile error when using NR_syscalls in kernel[1]. [1] https://lore.kernel.org/all/202203270449.WBYQF9X3-lkp@intel.com/ Signed-off-by: Yang Yang <yang.yang29@zte.com.cn> Signed-off-by: Matt Turner <mattst88@gmail.com> 
Reference to other arch likes x86_64 or arm64 to do this replacement.
To solve compile error when using NR_syscalls in kernel[1].

[1] https://lore.kernel.org/all/202203270449.WBYQF9X3-lkp@intel.com/

Signed-off-by: Yang Yang <yang.yang29@zte.com.cn>
Signed-off-by: Matt Turner <mattst88@gmail.com>
alpha: ret_from_fork can go straight to ret_to_user 2022-10-30T03:31:16+00:00 Al Viro viro@zeniv.linux.org.uk 2021-09-18T22:42:20+00:00 fa6a3bf7ff3734ff13764d1b9e36c48f93eb3677 We only hit ret_from_fork when the child is meant to return to userland (since 2012 or so). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> 
We only hit ret_from_fork when the child is meant to return to
userland (since 2012 or so).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
alpha: syscall exit cleanup 2022-10-30T03:31:15+00:00 Al Viro viro@zeniv.linux.org.uk 2021-09-18T22:38:15+00:00 e778eaecedcb0422dd81af23cf83546b4932fc19 $ret_success consists of two insn + branch to ret_from_syscall. The thing is, those insns are identical to the ones immediately preceding ret_from_syscall... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> 
$ret_success consists of two insn + branch to ret_from_syscall.
The thing is, those insns are identical to the ones immediately
preceding ret_from_syscall...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
alpha: fix handling of a3 on straced syscalls 2022-10-30T03:31:15+00:00 Al Viro viro@zeniv.linux.org.uk 2021-09-18T22:27:12+00:00 19a09e426893a3cb08b97147b8dc22bdfcab3bba For successful syscall that happens to return a negative, we want a3 set to 0, no matter whether it's straced or not. As it is, for straced case we leave the value it used to have on syscall entry. Easily fixed, fortunately... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> 
For successful syscall that happens to return a negative, we want
a3 set to 0, no matter whether it's straced or not.  As it is,
for straced case we leave the value it used to have on syscall
entry.  Easily fixed, fortunately...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
alpha: fix syscall entry in !AUDUT_SYSCALL case 2022-10-30T03:31:15+00:00 Al Viro viro@zeniv.linux.org.uk 2021-09-18T22:18:48+00:00 f7b2431a6d22f7a91c567708e071dfcd6d66db14 We only want to take the slow path if SYSCALL_TRACE or SYSCALL_AUDIT is set; on !AUDIT_SYSCALL configs the current tree hits it whenever _any_ thread flag (including NEED_RESCHED, NOTIFY_SIGNAL, etc.) happens to be set. Fixes: a9302e843944 "alpha: Enable system-call auditing support" Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> 
We only want to take the slow path if SYSCALL_TRACE or SYSCALL_AUDIT is
set; on !AUDIT_SYSCALL configs the current tree hits it whenever _any_
thread flag (including NEED_RESCHED, NOTIFY_SIGNAL, etc.) happens to
be set.

Fixes: a9302e843944 "alpha: Enable system-call auditing support"
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
alpha: add support for TIF_NOTIFY_SIGNAL 2020-12-12T16:16:34+00:00 Jens Axboe axboe@kernel.dk 2020-10-08T15:11:42+00:00 5a9a8897c253a075805401d38d987ec1ac1824b6 Wire up TIF_NOTIFY_SIGNAL handling for alpha. Cc: linux-alpha@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk> 
Wire up TIF_NOTIFY_SIGNAL handling for alpha.

Cc: linux-alpha@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
alpha: unify the glue for sigreturn-like syscalls 2018-08-17T01:03:35+00:00 Al Viro viro@zeniv.linux.org.uk 2018-08-17T01:03:35+00:00 8a68060cefa6db0e02600ac35deed0dc2fa6a68f Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> 
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>