Linux-EDAC Archive on lore.kernel.org
 help / color / Atom feed
* [tip:ras/core] RAS/CEC: Fix pfn insertion
@ 2019-06-08 21:25 tip-bot for Borislav Petkov
  0 siblings, 0 replies; only message in thread
From: tip-bot for Borislav Petkov @ 2019-06-08 21:25 UTC (permalink / raw)
  To: linux-tip-commits; +Cc: tony.luck, hpa, bp, tglx, mingo, linux-edac

Commit-ID:  6d8e294bf5f0e85c34e8b14b064e2965f53f38b0
Gitweb:     https://git.kernel.org/tip/6d8e294bf5f0e85c34e8b14b064e2965f53f38b0
Author:     Borislav Petkov <bp@suse.de>
AuthorDate: Sat, 20 Apr 2019 12:53:05 +0200
Committer:  Borislav Petkov <bp@suse.de>
CommitDate: Sat, 8 Jun 2019 17:32:00 +0200

RAS/CEC: Fix pfn insertion

When inserting random PFNs for debugging the CEC through
(debugfs)/ras/cec/pfn, depending on the return value of pfn_set(),
multiple values get inserted per a single write.

That is because simple_attr_write() interprets a retval of 0 as
success and claims the whole input. However, pfn_set() returns the
cec_add_elem() value, which, if > 0 and smaller than the whole input
length, makes glibc continue issuing the write syscall until there's
input left:

  pfn_set
  simple_attr_write
  debugfs_attr_write
  full_proxy_write
  vfs_write
  ksys_write
  do_syscall_64
  entry_SYSCALL_64_after_hwframe

leading to those repeated calls.

Return 0 to fix that.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
---
 drivers/ras/cec.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/ras/cec.c b/drivers/ras/cec.c
index 673f8a128397..f5795adc5a6e 100644
--- a/drivers/ras/cec.c
+++ b/drivers/ras/cec.c
@@ -369,7 +369,9 @@ static int pfn_set(void *data, u64 val)
 {
 	*(u64 *)data = val;
 
-	return cec_add_elem(val);
+	cec_add_elem(val);
+
+	return 0;
 }
 
 DEFINE_DEBUGFS_ATTRIBUTE(pfn_ops, u64_get, pfn_set, "0x%llx\n");

^ permalink raw reply	[flat|nested] only message in thread

only message in thread, back to index

Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-06-08 21:25 [tip:ras/core] RAS/CEC: Fix pfn insertion tip-bot for Borislav Petkov

Linux-EDAC Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-edac/0 linux-edac/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-edac linux-edac/ https://lore.kernel.org/linux-edac \
		linux-edac@vger.kernel.org linux-edac@archiver.kernel.org
	public-inbox-index linux-edac


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-edac


AGPL code for this site: git clone https://public-inbox.org/ public-inbox