From: "Steve Pratt/Austin/IBM" <slpratt@us.ibm.com>
To: linux-kernel@vger.kernel.org
Cc: torvalds@transmeta.com, linux-mm@kvack.org
Subject: [PATCH] 2.4.0-test10-pre6 TLB flush race in establish_pte
Date: Mon, 30 Oct 2000 15:31:22 -0600 [thread overview]
Message-ID: <OFB4731A18.0D8D8BC1-ON85256988.0074562B@raleigh.ibm.com> (raw)
Back in April there were discussions about the race in establish_pte with
the flush_tlb before the set_pte. Many options were discussed, but due in
part to a concern about S/390 having introduced the code, no patch ever
appeared. I talked with Martin Schwidefsky of the S/390 Linux development
team and he said that:
>the establish_pte was in fact introduced because of Linux/390. We wanted
to use the special S/390 instruction ipte (invalidate page >table entry).
In the meantime we found out that we need a lot more changes to be able to
use this instruction, so we disabled it again. >Until we have a proper
patch you should revoke the establish_pte change if you found it to be
faulty. I too think there is a race >condition.
So while there may be a more elegant solution down the road, I would like
to see the simple fix put back into 2.4. Here is the patch to essential
put the code back to the way it was before the S/390 merge. Patch is
against 2.4.0-test10pre6.
--- linux/mm/memory.c Fri Oct 27 15:26:14 2000
+++ linux-2.4.0-test10patch/mm/memory.c Fri Oct 27 15:45:54 2000
@@ -781,8 +781,8 @@
*/
static inline void establish_pte(struct vm_area_struct * vma, unsigned long address, pte_t *page_table, pte_t entry)
{
- flush_tlb_page(vma, address);
set_pte(page_table, entry);
+ flush_tlb_page(vma, address);
update_mmu_cache(vma, address, entry);
}
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next reply other threads:[~2000-10-30 21:32 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2000-10-30 21:31 Steve Pratt/Austin/IBM [this message]
2000-10-30 21:39 ` [PATCH] 2.4.0-test10-pre6 TLB flush race in establish_pte Kanoj Sarcar
2000-10-31 0:30 ` Andrea Arcangeli
2000-10-31 16:23 ` Steven Pratt
2000-10-31 16:44 ` Andrea Arcangeli
2000-10-31 18:42 Ulrich.Weigand
2000-10-31 19:13 ` Andrea Arcangeli
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