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authorD Scott Phillips2023-06-26 17:29:39 -0700
committerGreg Kroah-Hartman2023-09-13 09:43:03 +0200
commit8bf567b63c2afcc482041564d0ad0c4c2bf8cb09 (patch)
tree06aa46831a50f343c90754f927a2b167e57a7f9d /drivers/firmware
parente95d7a8a6edd14f8fab44c777dd7281db91f6ae2 (diff)
arm64: sdei: abort running SDEI handlers during crash
commit 5cd474e57368f0957c343bb21e309cf82826b1ef upstream. Interrupts are blocked in SDEI context, per the SDEI spec: "The client interrupts cannot preempt the event handler." If we crashed in the SDEI handler-running context (as with ACPI's AGDI) then we need to clean up the SDEI state before proceeding to the crash kernel so that the crash kernel can have working interrupts. Track the active SDEI handler per-cpu so that we can COMPLETE_AND_RESUME the handler, discarding the interrupted context. Fixes: f5df26961853 ("arm64: kernel: Add arch-specific SDEI entry code and CPU masking") Signed-off-by: D Scott Phillips <scott@os.amperecomputing.com> Cc: stable@vger.kernel.org Reviewed-by: James Morse <james.morse@arm.com> Tested-by: Mihai Carabas <mihai.carabas@oracle.com> Link: https://lore.kernel.org/r/20230627002939.2758-1-scott@os.amperecomputing.com Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/firmware')
-rw-r--r--drivers/firmware/arm_sdei.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/firmware/arm_sdei.c b/drivers/firmware/arm_sdei.c
index f9040bd61081..285fe7ad490d 100644
--- a/drivers/firmware/arm_sdei.c
+++ b/drivers/firmware/arm_sdei.c
@@ -1095,3 +1095,22 @@ int sdei_event_handler(struct pt_regs *regs,
return err;
}
NOKPROBE_SYMBOL(sdei_event_handler);
+
+void sdei_handler_abort(void)
+{
+ /*
+ * If the crash happened in an SDEI event handler then we need to
+ * finish the handler with the firmware so that we can have working
+ * interrupts in the crash kernel.
+ */
+ if (__this_cpu_read(sdei_active_critical_event)) {
+ pr_warn("still in SDEI critical event context, attempting to finish handler.\n");
+ __sdei_handler_abort();
+ __this_cpu_write(sdei_active_critical_event, NULL);
+ }
+ if (__this_cpu_read(sdei_active_normal_event)) {
+ pr_warn("still in SDEI normal event context, attempting to finish handler.\n");
+ __sdei_handler_abort();
+ __this_cpu_write(sdei_active_normal_event, NULL);
+ }
+}