From: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
To: <linux-kernel@vger.kernel.org>
Cc: <linux-mips@linux-mips.org>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Victor Kamensky <victor.kamensky@linaro.org>
Subject: [PATCH] uprobes: allow for a cache flush after ixol breakpoint creation
Date: Tue, 13 Dec 2016 11:40:57 +0100 [thread overview]
Message-ID: <1481625657-22850-1-git-send-email-marcin.nowakowski@imgtec.com> (raw)
Commit 72e6ae285a1d ('ARM: 8043/1: uprobes need icache flush after xol
write' has introduced an arch-specific method to ensure all caches are
flushed appropriately after an instruction is written to an XOL page.
However, when the XOL area is created and the out-of-line breakpoint
instruction is copied, caches are not flushed at all and stale data may
be found in icache.
Replace a simple copy_to_page() with arch_uprobe_copy_ixol() to allow
the arch to ensure all caches are updated accordingly.
This change fixes uprobes on MIPS InterAptiv (tested on Creator Ci40).
Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Ingo Molnar <mingo@redhat.com>
CC: Arnaldo Carvalho de Melo <acme@kernel.org>
CC: Alexander Shishkin <alexander.shishkin@linux.intel.com>
CC: Victor Kamensky <victor.kamensky@linaro.org>
---
kernel/events/uprobes.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index f9ec9ad..b5916b4 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1194,7 +1194,7 @@ static struct xol_area *__create_xol_area(unsigned long vaddr)
/* Reserve the 1st slot for get_trampoline_vaddr() */
set_bit(0, area->bitmap);
atomic_set(&area->slot_count, 1);
- copy_to_page(area->pages[0], 0, &insn, UPROBE_SWBP_INSN_SIZE);
+ arch_uprobe_copy_ixol(area->pages[0], 0, &insn, UPROBE_SWBP_INSN_SIZE);
if (!xol_add_vma(mm, area))
return area;
--
2.7.4
next reply other threads:[~2016-12-13 10:41 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-13 10:40 Marcin Nowakowski [this message]
2016-12-20 7:58 ` [tip:perf/urgent] uprobes: Fix uprobes on MIPS, allow for a cache flush after ixol breakpoint creation tip-bot for Marcin Nowakowski
2016-12-20 13:08 ` Oleg Nesterov
2016-12-20 15:21 ` Marcin Nowakowski
2016-12-20 17:50 ` Oleg Nesterov
2016-12-21 11:24 ` Ralf Baechle
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