[PATCH v11 5/5] arm64: send SIGBUS to user process for SEA exception
From: Tong Tiangen <hidden>
Date: 2024-02-07 13:22:27
Also in:
linux-arm-kernel, linux-mm, lkml
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
For SEA exception, kernel require take some action to recover from memory error, such as isolate poison page adn kill failure thread, which are done in memory_failure(). During the test, the failure thread cannot be killed due to this issue[1], Here, I temporarily workaround this issue by sending signals to user processes (!(PF_KTHREAD|PF_IO_WORKER|PF_WQ_WORKER|PF_USER_WORKER)) in do_sea(). After [1] is merged, this patch can be rolled back or the SIGBUS will be sent repeated. [1]https://lore.kernel.org/lkml/20240204080144.7977-1-xueshuai@linux.alibaba.com/ (local) Signed-off-by: Tong Tiangen <redacted> --- arch/arm64/mm/fault.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 78f9d5ce83bb..a27bb2de1a7c 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c@@ -824,9 +824,6 @@ static int do_sea(unsigned long far, unsigned long esr, struct pt_regs *regs) const struct fault_info *inf; unsigned long siaddr; - if (do_apei_claim_sea(regs)) - return 0; - inf = esr_to_fault_info(esr); if (esr & ESR_ELx_FnV) { siaddr = 0;
@@ -838,6 +835,19 @@ static int do_sea(unsigned long far, unsigned long esr, struct pt_regs *regs) */ siaddr = untagged_addr(far); } + + if (do_apei_claim_sea(regs)) { + if (!(current->flags & (PF_KTHREAD | + PF_USER_WORKER | + PF_WQ_WORKER | + PF_IO_WORKER))) { + set_thread_esr(0, esr); + arm64_force_sig_fault(inf->sig, inf->code, siaddr, + "Uncorrected memory error on access to poison memory\n"); + } + return 0; + } + arm64_notify_die(inf->name, regs, inf->sig, inf->code, siaddr, esr); return 0;
--
2.25.1