7 Commits

Author SHA1 Message Date
Benjamin Herrenschmidt
31de991dee kern/acpi: Fix out of bounds access in grub_acpi_xsdt_find_table()
The calculation of the size of the table was incorrect (copy/pasta from
grub_acpi_rsdt_find_table() I assume...). The entries are 64-bit long.

This causes us to access beyond the end of the table which is causing
crashes during boot on some systems. Typically this is causing a crash
on VMWare when using UEFI and enabling serial autodetection, as

  grub_acpi_find_table (GRUB_ACPI_SPCR_SIGNATURE);

will goes past the end of the table (the SPCR table doesn't exits).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
Tested-by: Renata Ravanelli <rravanel@redhat.com>
2024-10-31 16:04:00 +01:00
Michael Chang
48f569c78a kern/acpi: Skip NULL entries in RSDT and XSDT
During attempts to configure a serial console, a Page Fault Exception
and system reset were encountered, specifically on release 2.12~rc1.
This issue was not present in prior versions and seemed to affect only
a specific machine, potentially pointing to hardware or firmware flaw.

After investigation, it was discovered that the invalid page access
occurred during the discovery of serial MMIO ports as specified by
ACPI's SPCR table [1]. The recent change uncovered an issue in GRUB's
ACPI driver.

In certain cases, the XSDT/RSDT root table might contain a NULL entry as
a terminator, depending on how the tables are assembled. GRUB cannot
blindly trust the address in the root table to be valid and should
perform a sanity check for NULL entries. This patch introduces this
simple check.

This fix is also inspired by a related Linux kernel fix [2].

[1] 7b192ec4c term/ns8250: Use ACPI SPCR table when available to configure serial
[2] 0f929fbf0 ACPICA: Tables: Add new mechanism to skip NULL entries in RSDT and XSDT.

Signed-off-by: Michael Chang <mchang@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2023-10-03 15:38:48 +02:00
Qiumiao Zhang
4fb58cf0af kern/acpi: Use xsdt_addr if present
According to the ACPI specification, in ACPI 2.0 or later, an
ACPI-compatible OS must use the XSDT if present. So, we should
use xsdt_addr instead of rsdt_addr if xsdt_addr is valid.

Signed-off-by: Qiumiao Zhang <zhangqiumiao1@huawei.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2023-06-13 16:00:39 +02:00
Benjamin Herrenschmidt
cff78b3b61 kern/acpi: Export a generic grub_acpi_find_table()
And convert grub_acpi_find_fadt() to use it.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2023-01-18 23:07:06 +01:00
Elyes Haouas
edd9af9192 kern: Remove trailing whitespaces
Signed-off-by: Elyes Haouas <ehaouas@noos.fr>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2022-03-14 15:46:55 +01:00
Vladimir Serbinenko
b29638222e Make grub_acpi_find_fadt accessible generically 2016-02-12 11:35:48 +01:00
Vladimir Serbinenko
d43a5ee651 tsc: Use alternative delay sources whenever appropriate.
PIT isn't available on some of new hardware including Hyper-V. So
use pmtimer for calibration. Moreover pmtimer calibration is faster, so
use it on coreboor where booting time is important.

Based on patch by Michael Chang.
2015-11-27 11:39:55 +01:00