Messages in this thread Patch in this message | | | Date | Mon, 19 Sep 2016 11:44:51 +0100 | From | Mark Rutland <> | Subject | Re: [RFC PATCH 2/8] thread_info: allow custom in-task thread_info |
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[Adding Yosinori Sato for h8300]
On Fri, Sep 16, 2016 at 08:11:14AM -0700, Andy Lutomirski wrote: > > On Thu, Sep 15, 2016 at 11:37:47AM -0700, Andy Lutomirski wrote: > > > On Thu, Sep 15, 2016 at 6:49 AM, Mark Rutland <mark.rutland@arm.com> wrote: > > Just to check, what do you mean to happen with the flags field? Should > > that always be in the generic thread_info? e.g. > > > > struct thread_info { > > u32 flags; > > #ifdef arch_thread_info > > struct arch_thread_info arch_ti; > > #endif > > }; > > Exactly. Possibly with a comment that using thread_struct should be > preferred and that arch_thread_info should be used only if some header > file requires access via current_thread_info() or task_thread_info().
Sure thing.
While looking at that, I spotted that would cause a circular include on h8300, but that appears to be because of a larger bug anyhow. It seems h8300 has thread_info::restart_block, and manipulates this in its signal code, yet core code manipulates task_struct::restart_block.
I think we need something like the below (which is completely untested).
Thanks, Mark.
---->8---- From 4dfbdc7706bfb03a48999ff69e85e0c7361adffe Mon Sep 17 00:00:00 2001 From: Mark Rutland <mark.rutland@arm.com> Date: Mon, 19 Sep 2016 11:33:42 +0100 Subject: [PATCH] h8300: fix syscall restarting
Back in commit f56141e3e2d9aabf ("all arches, signal: move restart_block to struct task_struct"), all architectures and core code were changed to use task_struct::restart_block. However, when h8300 support was subsequently restored in v4.2, it was not updated to account for this, and maintains thread_info::restart_block, which is not kept in sync.
This patch drops the redundant restart_block from thread_info, and moves h8300 to the common one in task_struct, ensuring that syscall restarting always works as expected.
Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: stable@vger.kernel.org # v4.2+ --- arch/h8300/include/asm/thread_info.h | 4 ---- arch/h8300/kernel/signal.c | 2 +- 2 files changed, 1 insertion(+), 5 deletions(-)
diff --git a/arch/h8300/include/asm/thread_info.h b/arch/h8300/include/asm/thread_info.h index b408fe6..3cef068 100644 --- a/arch/h8300/include/asm/thread_info.h +++ b/arch/h8300/include/asm/thread_info.h @@ -31,7 +31,6 @@ struct thread_info { int cpu; /* cpu we're on */ int preempt_count; /* 0 => preemptable, <0 => BUG */ mm_segment_t addr_limit; - struct restart_block restart_block; }; /* @@ -44,9 +43,6 @@ struct thread_info { .cpu = 0, \ .preempt_count = INIT_PREEMPT_COUNT, \ .addr_limit = KERNEL_DS, \ - .restart_block = { \ - .fn = do_no_restart_syscall, \ - }, \ } #define init_thread_info (init_thread_union.thread_info) diff --git a/arch/h8300/kernel/signal.c b/arch/h8300/kernel/signal.c index ad1f81f..7138303 100644 --- a/arch/h8300/kernel/signal.c +++ b/arch/h8300/kernel/signal.c @@ -79,7 +79,7 @@ restore_sigcontext(struct sigcontext *usc, int *pd0) unsigned int er0; /* Always make any pending restarted system calls return -EINTR */ - current_thread_info()->restart_block.fn = do_no_restart_syscall; + current->restart_block.fn = do_no_restart_syscall; /* restore passed registers */ #define COPY(r) do { err |= get_user(regs->r, &usc->sc_##r); } while (0) -- 1.9.1
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