From f3c238866bf64e6109ad0c1d3b0056d3b979ca68 Mon Sep 17 00:00:00 2001 From: tangbinzy Date: Tue, 18 Jul 2023 06:07:25 +0000 Subject: [PATCH] acpi: fix OEM ID/OEM Table ID padding mainline inclusion commit 748c030f360a940fe0c9382c8ca1649096c3a80d category: bugfix --------------------------------------------------------------- Commit [2] broke original '\0' padding of OEM ID and OEM Table ID fields in headers of ACPI tables. While it doesn't have impact on default values since QEMU uses 6 and 8 characters long values respectively, it broke usecase where IDs are provided on QEMU CLI. It shouldn't affect guest (but may cause licensing verification issues in guest OS). One of the broken usecases is user supplied SLIC table with IDs shorter than max possible length, where [2] mangles IDs with extra spaces in RSDT and FADT tables whereas guest OS expects those to mirror the respective values of the used SLIC table. Fix it by replacing whitespace padding with '\0' padding in accordance with [1] and expectations of guest OS 1) ACPI spec, v2.0b 17.2 AML Grammar Definition ... //OEM ID of up to 6 characters. If the OEM ID is //shorter than 6 characters, it can be terminated //with a NULL character. 2) Fixes: 602b458201 ("acpi: Permit OEM ID and OEM table ID fields to be changed") Resolves: https://gitlab.com/qemu-project/qemu/-/issues/707 Reported-by: Dmitry V. Orekhov Signed-off-by: Igor Mammedov Cc: qemu-stable@nongnu.org Message-Id: <20220112130332.1648664-4-imammedo@redhat.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Reviewed-by: Ani Sinha Tested-by: Dmitry V. Orekhov dima.orekhov@gmail.com Signed-off-by: tangbinzy --- hw/acpi/aml-build.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c index 39b8d807c09..fd35cfb6bb8 100644 --- a/hw/acpi/aml-build.c +++ b/hw/acpi/aml-build.c @@ -1746,9 +1746,9 @@ void acpi_table_begin(AcpiTable *desc, GArray *array) build_append_int_noprefix(array, 0, 4); /* Length */ build_append_int_noprefix(array, desc->rev, 1); /* Revision */ build_append_int_noprefix(array, 0, 1); /* Checksum */ - build_append_padded_str(array, desc->oem_id, 6, ' '); /* OEMID */ + build_append_padded_str(array, desc->oem_id, 6, '\0'); /* OEMID */ /* OEM Table ID */ - build_append_padded_str(array, desc->oem_table_id, 8, ' '); + build_append_padded_str(array, desc->oem_table_id, 8, '\0'); build_append_int_noprefix(array, 1, 4); /* OEM Revision */ g_array_append_vals(array, ACPI_BUILD_APPNAME8, 4); /* Creator ID */ build_append_int_noprefix(array, 1, 4); /* Creator Revision */ -- Gitee