From 6d8e294bf5f0e85c34e8b14b064e2965f53f38b0 Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Sat, 20 Apr 2019 12:53:05 +0200 Subject: 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 Cc: Tony Luck Cc: linux-edac --- drivers/ras/cec.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/ras') 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"); -- cgit v1.2.3-55-g7522