Re: [PATCH 4/6] x86/coredump: use core regs, rather that TIF_IA32 flag
From: Dmitry Safonov
Date: Wed Jun 08 2016 - 09:30:34 EST
On 06/07/2016 01:43 AM, Oleg Nesterov wrote:
On 06/06, Oleg Nesterov wrote:
On 06/01, Dmitry Safonov wrote:
static int fill_thread_core_info(struct elf_thread_core_info *t,
const struct user_regset_view *view,
- long signr, size_t *total)
+ long signr, size_t *total,
+ struct pt_regs *regs __maybe_unused)
{
unsigned int i;
@@ -1652,11 +1653,11 @@ static int fill_thread_core_info(struct elf_thread_core_info *t,
*/
fill_prstatus(&t->prstatus, t->task, signr);
(void) view->regsets[0].get(t->task, &view->regsets[0],
- 0, PR_REG_SIZE(t->prstatus.pr_reg),
+ 0, PR_REG_SIZE(t->prstatus.pr_reg, regs),
Hmm. I don't understand this... Note that this "regs" argument has nothing
to do with t->task if the process is multithreaded,
@@ -1772,7 +1773,8 @@ static int fill_note_info(struct elfhdr *elf, int phdrs,
* Now fill in each thread's information.
*/
for (t = info->thread; t != NULL; t = t->next)
- if (!fill_thread_core_info(t, view, siginfo->si_signo, &info->size))
+ if (!fill_thread_core_info(t, view, siginfo->si_signo,
+ &info->size, regs))
fill_note_info(..., args) is called with args = task_pt_regs(dumper_thread).
forgot to mention... yes, this matches the fact we use a single "view"
for all threads, and we get it via task_user_regset_view(dump_task).
But this change (imo) adds even more confusion, and without the next patch
the logic looks "obviously wrong", becauase PR_REG_SIZE/etc look at
dumper_thread->cs while task_user_regset_view() checks thread flags.
Anyway I fail to understand these macros... Say, PR_REG_SIZE(S). Can't we
kill it and use regsets[0].n * regsets[0].size instead ? These numbers
should match whatever we do, if we call ->get().
Thanks, the idea of dropping PR_REG_SIZE looks better than my patch!
I'll try to drop those macros for the next revision.
--
Regards,
Dmitry Safonov