From 5e1a00969afe98a713bf14d1ba1902403b60e287 Mon Sep 17 00:00:00 2001 From: Christopher Clark Date: Thu, 16 Aug 2018 13:04:52 -0700 Subject: [PATCH v2] libxl/arm: Fix build on arm64 + acpi w/ gcc 8.2 To: xen-devel@lists.xenproject.org Cc: wei.liu2@citrix.com, ian.jackson@eu.citrix.com, julien.grall@arm.com, sstabellini@kernel.org [modified for Xen 4.11 to add required: #include ] Add zero-padding to #defined ACPI table strings that are copied. Provides sufficient characters to satisfy the length required to fully populate the destination and prevent array-bounds warnings. Add BUILD_BUG_ON sizeof checks for compile-time length checking. Signed-off-by: Christopher Clark Reviewed-by: Stefano Stabellini Acked-by: Wei Liu --- v2: add BUILD_BUG_ON length checks, requested by Wei. v1: Please add this patch to the backport list for the next minor 4.11 release. Prior to this: gcc 8.2 objects to memcpy past bounds: | libxl_arm_acpi.c: In function 'make_acpi_header': | libxl_arm_acpi.c:208:5: error: 'memcpy' forming offset [5, 6] is out of the bounds [0, 4] [-Werror=array-bounds] | memcpy(h->oem_id, ACPI_OEM_ID, sizeof(h->oem_id)); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | libxl_arm_acpi.c:209:5: error: 'memcpy' forming offset [5, 8] is out of the bounds [0, 4] [-Werror=array-bounds] | memcpy(h->oem_table_id, ACPI_OEM_TABLE_ID, sizeof(h->oem_table_id)); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | libxl_arm_acpi.c:211:5: error: 'memcpy' forming offset 4 is out of the bounds [0, 3] [-Werror=array-bounds] | memcpy(h->asl_compiler_id, ACPI_ASL_COMPILER_ID, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | sizeof(h->asl_compiler_id)); | ~~~~~~~~~~~~~~~~~~~~~~~~~~~ | In function 'make_acpi_rsdp.isra.4', | inlined from 'libxl__prepare_acpi' at libxl_arm_acpi.c:389:5: | libxl_arm_acpi.c:193:5: error: 'memcpy' forming offset [5, 6] is out of the bounds [0, 4] [-Werror=array-bounds] | memcpy(rsdp->oem_id, ACPI_OEM_ID, sizeof(rsdp->oem_id)); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ tools/libxl/libxl_arm_acpi.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/tools/libxl/libxl_arm_acpi.c b/tools/libxl/libxl_arm_acpi.c index 636f724..8924396 100644 --- a/tools/libxl/libxl_arm_acpi.c +++ b/tools/libxl/libxl_arm_acpi.c @@ -29,6 +29,7 @@ typedef int64_t s64; #include #include +#include #ifndef BITS_PER_LONG #ifdef _LP64 @@ -48,9 +49,9 @@ extern const unsigned char dsdt_anycpu_arm[]; _hidden extern const int dsdt_anycpu_arm_len; -#define ACPI_OEM_ID "Xen" -#define ACPI_OEM_TABLE_ID "ARM" -#define ACPI_ASL_COMPILER_ID "XL" +#define ACPI_OEM_ID "Xen\0\0" +#define ACPI_OEM_TABLE_ID "ARM\0\0\0\0" +#define ACPI_ASL_COMPILER_ID "XL\0" enum { RSDP, @@ -190,6 +191,7 @@ static void make_acpi_rsdp(libxl__gc *gc, struct xc_dom_image *dom, struct acpi_table_rsdp *rsdp = (void *)dom->acpi_modules[0].data + offset; memcpy(rsdp->signature, "RSD PTR ", sizeof(rsdp->signature)); + BUILD_BUG_ON(sizeof(ACPI_OEM_ID) != sizeof(rsdp->oem_id)); memcpy(rsdp->oem_id, ACPI_OEM_ID, sizeof(rsdp->oem_id)); rsdp->length = acpitables[RSDP].size; rsdp->revision = 0x02; @@ -205,9 +207,12 @@ static void make_acpi_header(struct acpi_table_header *h, const char *sig, memcpy(h->signature, sig, 4); h->length = len; h->revision = rev; + BUILD_BUG_ON(sizeof(ACPI_OEM_ID) != sizeof(h->oem_id)); memcpy(h->oem_id, ACPI_OEM_ID, sizeof(h->oem_id)); + BUILD_BUG_ON(sizeof(ACPI_OEM_TABLE_ID) != sizeof(h->oem_table_id)); memcpy(h->oem_table_id, ACPI_OEM_TABLE_ID, sizeof(h->oem_table_id)); h->oem_revision = 0; + BUILD_BUG_ON(sizeof(ACPI_ASL_COMPILER_ID) != sizeof(h->asl_compiler_id)); memcpy(h->asl_compiler_id, ACPI_ASL_COMPILER_ID, sizeof(h->asl_compiler_id)); h->asl_compiler_revision = 0;