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authorGerald Schaefer <gerald.schaefer@linux.ibm.com>2024-07-15 20:04:16 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-07-27 11:36:15 +0200
commit9e13767ccefdc4f8aa92514b592b60f6b54882ff (patch)
tree4e2fbe8b7f4250cd72daf8184e731d0eb2546a84
parentd347c9a398bf7eab9408d207c0a50fb720f9de7d (diff)
s390/mm: Fix VM_FAULT_HWPOISON handling in do_exception()
commit df39038cd89525d465c2c8827eb64116873f141a upstream. There is no support for HWPOISON, MEMORY_FAILURE, or ARCH_HAS_COPY_MC on s390. Therefore we do not expect to see VM_FAULT_HWPOISON in do_exception(). However, since commit af19487f00f3 ("mm: make PTE_MARKER_SWAPIN_ERROR more general"), it is possible to see VM_FAULT_HWPOISON in combination with PTE_MARKER_POISONED, even on architectures that do not support HWPOISON otherwise. In this case, we will end up on the BUG() in do_exception(). Fix this by treating VM_FAULT_HWPOISON the same as VM_FAULT_SIGBUS, similar to x86 when MEMORY_FAILURE is not configured. Also print unexpected fault flags, for easier debugging. Note that VM_FAULT_HWPOISON_LARGE is not expected, because s390 cannot support swap entries on other levels than PTE level. Cc: stable@vger.kernel.org # 6.6+ Fixes: af19487f00f3 ("mm: make PTE_MARKER_SWAPIN_ERROR more general") Reported-by: Yunseong Kim <yskelg@gmail.com> Tested-by: Yunseong Kim <yskelg@gmail.com> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Message-ID: <20240715180416.3632453-1-gerald.schaefer@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--arch/s390/mm/fault.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index 0c66b32e0f9f..063a6ea378aa 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -432,12 +432,13 @@ error:
handle_fault_error_nolock(regs, 0);
else
do_sigsegv(regs, SEGV_MAPERR);
- } else if (fault & VM_FAULT_SIGBUS) {
+ } else if (fault & (VM_FAULT_SIGBUS | VM_FAULT_HWPOISON)) {
if (!user_mode(regs))
handle_fault_error_nolock(regs, 0);
else
do_sigbus(regs);
} else {
+ pr_emerg("Unexpected fault flags: %08x\n", fault);
BUG();
}
}