The following commit has been merged into the ras/core branch of tip: Commit-ID: e40879b6d7d858b03813cd53c17dfef9c297f525 Gitweb: https://git.kernel.org/tip/e40879b6d7d858b03813cd53c17dfef9c297f525 Author: Yazen Ghannam <yazen.ghannam@xxxxxxx> AuthorDate: Fri, 08 Jan 2021 04:00:35 Committer: Borislav Petkov (AMD) <bp@xxxxxxxxx> CommitterDate: Tue, 16 May 2023 12:16:22 +02:00 x86/MCE: Check a hw error's address to determine proper recovery action Make sure that machine check errors with a usable address are properly marked as poison. This is needed for errors that occur on memory which have MCG_STATUS[RIPV] clear - i.e., the interrupted process cannot be restarted reliably. One example is data poison consumption through the instruction fetch units on AMD Zen-based systems. The MF_MUST_KILL flag is passed to memory_failure() when MCG_STATUS[RIPV] is not set. So the associated process will still be killed. What this does, practically, is get rid of one more check to kill_current_task with the eventual goal to remove it completely. Also, make the handling identical to what is done on the notifier path (uc_decode_notifier() does that address usability check too). The scenario described above occurs when hardware can precisely identify the address of poisoned memory, but execution cannot reliably continue for the interrupted hardware thread. [ bp: Massage commit message. ] Signed-off-by: Yazen Ghannam <yazen.ghannam@xxxxxxx> Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx> Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx> Link: https://lore.kernel.org/r/20230322005131.174499-1-tony.luck@xxxxxxxxx --- arch/x86/kernel/cpu/mce/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c index 2eec60f..22dfcb2 100644 --- a/arch/x86/kernel/cpu/mce/core.c +++ b/arch/x86/kernel/cpu/mce/core.c @@ -1533,7 +1533,7 @@ noinstr void do_machine_check(struct pt_regs *regs) /* If this triggers there is no way to recover. Die hard. */ BUG_ON(!on_thread_stack() || !user_mode(regs)); - if (kill_current_task) + if (!mce_usable_address(&m)) queue_task_work(&m, msg, kill_me_now); else queue_task_work(&m, msg, kill_me_maybe);
|