[PATCH] acpi: fadt: check 32/64 bit PM register addresses for inconsistency (LP: #1536606)

[Colin King]

From: Colin Ian King <colin.king at canonical.com>

A HP BIOS was found in the wild that had a 64 bit PM register that was
different to the 32 bit PM register, and the 32 bit address was correct
but the 64 bit address was not. This is unreconcileable. Which one is
correct?

Upstream ACPICA commit 4da56eeae0749dfe8491285c1e1fad48f6efafd8 defaulted
to using 64 bit address by default which is now causing systems to become
unbootable (c.f. LP#1529381).

I think it is prudent to check for these inconsistencies as yet another
level of sanity checking.

Signed-off-by: Colin Ian King <colin.king at canonical.com>
---
 src/acpi/fadt/fadt.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 50 insertions(+), 1 deletion(-)

diff --git a/src/acpi/fadt/fadt.c b/src/acpi/fadt/fadt.c
index 7556bf5..0f3739b 100644
--- a/src/acpi/fadt/fadt.c
+++ b/src/acpi/fadt/fadt.c
@@ -300,6 +300,55 @@ static void acpi_table_check_fadt_gpe(
 	}
 }
 
+static void acpi_table_check_fadt_addr(
+	fwts_framework *fw,
+	const char *name,
+	const uint32_t addr32,
+	const fwts_acpi_gas *addr64,
+	bool *passed)
+{
+	/* Don't compare if addresses are zero */
+	if ((addr32 == 0) || (addr64->address == 0))
+		return;
+	if (addr32 == addr64->address)
+		return;
+
+	*passed = false;
+	/*
+	 * Since this can cause systems to misbehave
+	 * if the kernel uses the incorrect address we
+	 * make this LOG_LEVEL_HIGH
+	 */
+	fwts_failed(fw, LOG_LEVEL_HIGH,
+		"FADTPmAddr32Addr64Different",
+		"FADT %s (32 bit address) 0x%" PRIx32 " is different from "
+		"X_%s (64 bit address) 0x%" PRIx64 ".",
+		name, addr32, name, addr64->address);
+}
+
+static void acpi_table_check_fadt_pm_addr(
+	fwts_framework *fw,
+	const fwts_acpi_table_fadt *fadt,
+	bool *passed)
+{
+	if (fadt->header.length < 148) {
+		/* No 64 bit PM addresses to sanity check */
+		return;
+	}
+	acpi_table_check_fadt_addr(fw, "PM1a_EVT_BLK", fadt->pm1a_evt_blk,
+			&fadt->x_pm1a_evt_blk, passed);
+	acpi_table_check_fadt_addr(fw, "PM1b_EVT_BLK", fadt->pm1b_evt_blk,
+			&fadt->x_pm1b_evt_blk, passed);
+	acpi_table_check_fadt_addr(fw, "PM1a_CNT_BLK", fadt->pm1a_cnt_blk,
+			&fadt->x_pm1a_cnt_blk, passed);
+	acpi_table_check_fadt_addr(fw, "PM1b_CNT_BLK", fadt->pm1b_cnt_blk,
+			&fadt->x_pm1b_cnt_blk, passed);
+	acpi_table_check_fadt_addr(fw, "PM2_CNT_BLK", fadt->pm2_cnt_blk,
+			&fadt->x_pm2_cnt_blk, passed);
+	acpi_table_check_fadt_addr(fw, "PM_TMR_BLK", fadt->pm_tmr_blk,
+			&fadt->x_pm_tmr_blk, passed);
+}
+
 static int fadt_test1(fwts_framework *fw)
 {
 	bool passed = true;
@@ -309,6 +358,7 @@ static int fadt_test1(fwts_framework *fw)
 	acpi_table_check_fadt_smi(fw, fadt, &passed);
 	acpi_table_check_fadt_pm_tmr(fw, fadt, &passed);
 	acpi_table_check_fadt_gpe(fw, fadt, &passed);
+	acpi_table_check_fadt_pm_addr(fw, fadt, &passed);
 
 	/*
 	 * Bug LP: #833644
@@ -341,7 +391,6 @@ static int fadt_test1(fwts_framework *fw)
 	return FWTS_OK;
 }
 
-
 static int fadt_test2(fwts_framework *fw)
 {
 	uint32_t port, width, val32;
-- 
2.7.0.rc3