Re: [PATCH] core dump: user_regset writeback

From: Andrew Morton
Date: Thu Feb 28 2008 - 15:47:10 EST


On Wed, 27 Feb 2008 12:06:38 -0800 (PST)
Roland McGrath <roland@xxxxxxxxxx> wrote:

>
> This makes the user_regset-based core dump code call user_regset
> writeback hooks when available. This is necessary groundwork to
> allow IA64 to set CORE_DUMP_USE_REGSET.
>
> CC: Shaohua Li <shaohua.li@xxxxxxxxx>
> Signed-off-by: Roland McGrath <roland@xxxxxxxxxx>
> ---
> fs/binfmt_elf.c | 15 +++++++++++++++
> 1 files changed, 15 insertions(+), 0 deletions(-)
>
> diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
> index 41a958a..eb7cca3 100644
> --- a/fs/binfmt_elf.c
> +++ b/fs/binfmt_elf.c
> @@ -1424,6 +1424,18 @@ struct elf_note_info {
> int thread_notes;
> };
>
> +/*
> + * When a regset has a writeback hook, we call it on each thread before
> + * dumping user memory. On register window machines, this makes sure the
> + * user memory backing the register data is up to date before we read it.
> + */
> +static void do_thread_regset_writeback(struct task_struct *task,
> + const struct user_regset *regset)
> +{
> + if (regset->writeback)
> + regset->writeback(task, regset, 1);
> +}
> +
> static int fill_thread_core_info(struct elf_thread_core_info *t,
> const struct user_regset_view *view,
> long signr, size_t *total)
> @@ -1445,6 +1457,8 @@ static int fill_thread_core_info(struct elf_thread_core_info *t,
> sizeof(t->prstatus), &t->prstatus);
> *total += notesize(&t->notes[0]);
>
> + do_thread_regset_writeback(t->task, &view->regsets[0]);
> +
> /*
> * Each other regset might generate a note too. For each regset
> * that has no core_note_type or is inactive, we leave t->notes[i]
> @@ -1452,6 +1466,7 @@ static int fill_thread_core_info(struct elf_thread_core_info *t,
> */
> for (i = 1; i < view->n; ++i) {
> const struct user_regset *regset = &view->regsets[i];
> + do_thread_regset_writeback(t->task, regset);
> if (regset->core_note_type &&
> (!regset->active || regset->active(t->task, regset))) {
> int ret;

Is there a need for this in 2.6.25?
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