[PATCH] x86/PAT: priority the PAT warn to error to highlight the developer

From: jun . zhang
Date: Sun Sep 29 2019 - 03:40:46 EST


From: zhang jun <jun.zhang@xxxxxxxxx>

Documentation/x86/pat.txt says:
set_memory_uc() or set_memory_wc() must use together with set_memory_wb()

if break the PAT attribute, there are tons of warning like:
[ 45.846872] x86/PAT: NDK MediaCodec_:3753 map pfn RAM range req
write-combining for [mem 0x1e7a80000-0x1e7a87fff], got write-back
and in the extremely case, we see kernel panic unexpected like:
list_del corruption. prev->next should be ffff88806dbe69c0,
but was ffff888036f048c0

so it's better to priority the warn to error to highlight to
remind the developer.

Signed-off-by: zhang jun <jun.zhang@xxxxxxxxx>
Signed-off-by: he, bo <bo.he@xxxxxxxxx>
---
arch/x86/mm/pat.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index d9fbd4f69920..43a4dfdcedc8 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -897,7 +897,7 @@ static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t *vma_prot,

pcm = lookup_memtype(paddr);
if (want_pcm != pcm) {
- pr_warn("x86/PAT: %s:%d map pfn RAM range req %s for [mem %#010Lx-%#010Lx], got %s\n",
+ pr_err("x86/PAT: %s:%d map pfn RAM range req %s for [mem %#010Lx-%#010Lx], got %s!!!\n",
current->comm, current->pid,
cattr_name(want_pcm),
(unsigned long long)paddr,
--
2.17.1