On Thu Sep 5, 2024 at 6:04 AM EEST, Shuai Xue wrote: > > > 在 2024/9/4 00:09, Jarkko Sakkinen 写道: > > On Mon Sep 2, 2024 at 6:00 AM EEST, Shuai Xue wrote: > >> Synchronous error was detected as a result of user-space process accessing > >> a 2-bit uncorrected error. The CPU will take a synchronous error exception > >> such as Synchronous External Abort (SEA) on Arm64. The kernel will queue a > >> memory_failure() work which poisons the related page, unmaps the page, and > >> then sends a SIGBUS to the process, so that a system wide panic can be > >> avoided. > >> > >> However, no memory_failure() work will be queued unless all bellow > >> preconditions check passed: > >> > >> - `if (!(mem_err->validation_bits & CPER_MEM_VALID_PA))` in ghes_handle_memory_failure() > >> - `if (flags == -1)` in ghes_handle_memory_failure() > >> - `if (!IS_ENABLED(CONFIG_ACPI_APEI_MEMORY_FAILURE))` in ghes_do_memory_failure() > >> - `if (!pfn_valid(pfn) && !arch_is_platform_page(physical_addr)) ` in ghes_do_memory_failure() > >> > >> In such case, the user-space process will trigger SEA again. This loop > >> can potentially exceed the platform firmware threshold or even trigger a > >> kernel hard lockup, leading to a system reboot. > >> > >> Fix it by performing a force kill if no memory_failure() work is queued > >> for synchronous errors. > >> > >> Suggested-by: Xiaofei Tan <tanxiaofei@xxxxxxxxxx> > >> Signed-off-by: Shuai Xue <xueshuai@xxxxxxxxxxxxxxxxx> > >> > >> --- > >> drivers/acpi/apei/ghes.c | 10 ++++++++++ > >> 1 file changed, 10 insertions(+) > >> > >> diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c > >> index 623cc0cb4a65..b0b20ee533d9 100644 > >> --- a/drivers/acpi/apei/ghes.c > >> +++ b/drivers/acpi/apei/ghes.c > >> @@ -801,6 +801,16 @@ static bool ghes_do_proc(struct ghes *ghes, > >> } > >> } > >> > >> + /* > >> + * If no memory failure work is queued for abnormal synchronous > >> + * errors, do a force kill. > >> + */ > >> + if (sync && !queued) { > >> + pr_err("Sending SIGBUS to %s:%d due to hardware memory corruption\n", > >> + current->comm, task_pid_nr(current)); > > > > Hmm... doest this need "hardware" or would "memory corruption" be > > enough? > > > > Also, does this need to say that it is sending SIGBUS when the signal > > itself tells that already? > > > > I.e. could "%s:%d has memory corruption" be enough information? > > Hi, Jarkko, > > Thank you for your suggestion. Maybe it could. > > There are some similar error info which use "hardware memory error", e.g. By tweaking my original suggestion just a bit: "%s:%d: hardware memory corruption" Can't get clearer than that, right? BR, Jarkko