From: John Hubbard <jhubb...@nvidia.com> commit a90118c445cc7f07781de26a9684d4ec58bfcfd1 upstream.
Recent gcc compilers (gcc 9.1) generate warnings about an out of bounds memset, if the memset goes accross several fields of a struct. This generated a couple of warnings on x86_64 builds in sanitize_boot_params(). Fix this by explicitly saving the fields in struct boot_params that are intended to be preserved, and zeroing all the rest. [ tglx: Tagged for stable as it breaks the warning free build there as well ] Suggested-by: Thomas Gleixner <t...@linutronix.de> Suggested-by: H. Peter Anvin <h...@zytor.com> Signed-off-by: John Hubbard <jhubb...@nvidia.com> Signed-off-by: Thomas Gleixner <t...@linutronix.de> Cc: sta...@vger.kernel.org Link: https://lkml.kernel.org/r/20190731054627.5627-2-jhubb...@nvidia.com Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- Fix the following build warning. It has been merge to 5.2.11. Please consider merging if it's worth. ./arch/x86/include/asm/bootparam_utils.h:40:3: warning: ‘memset’ offset [197, 448] from the object at ‘boot_params’ is out of the bounds of referenced subobject ‘ext_ramdisk_image’ with type ‘unsigned int’ at offset 192 [-Warray-bounds] ./arch/x86/include/asm/bootparam_utils.h:43:3: warning: ‘memset’ offset [493, 497] from the object at ‘boot_params’ is out of the bounds of referenced subobject ‘kbd_status’ with type ‘unsig ned char’ at offset 491 [-Warray-bounds] arch/x86/include/asm/bootparam_utils.h | 63 ++++++++++++++++++++++++++-------- 1 file changed, 48 insertions(+), 15 deletions(-) diff --git a/arch/x86/include/asm/bootparam_utils.h b/arch/x86/include/asm/bootparam_utils.h index f6f6ef4..7fed0fc 100644 --- a/arch/x86/include/asm/bootparam_utils.h +++ b/arch/x86/include/asm/bootparam_utils.h @@ -18,6 +18,20 @@ * Note: efi_info is commonly left uninitialized, but that field has a * private magic, so it is better to leave it unchanged. */ + +#define sizeof_mbr(type, member) ({ sizeof(((type *)0)->member); }) + +#define BOOT_PARAM_PRESERVE(struct_member) \ + { \ + .start = offsetof(struct boot_params, struct_member), \ + .len = sizeof_mbr(struct boot_params, struct_member), \ + } + +struct boot_params_to_save { + unsigned int start; + unsigned int len; +}; + static void sanitize_boot_params(struct boot_params *boot_params) { /* @@ -35,21 +49,40 @@ static void sanitize_boot_params(struct boot_params *boot_params) * problems again. */ if (boot_params->sentinel) { - /* fields in boot_params are left uninitialized, clear them */ - boot_params->acpi_rsdp_addr = 0; - memset(&boot_params->ext_ramdisk_image, 0, - (char *)&boot_params->efi_info - - (char *)&boot_params->ext_ramdisk_image); - memset(&boot_params->kbd_status, 0, - (char *)&boot_params->hdr - - (char *)&boot_params->kbd_status); - memset(&boot_params->_pad7[0], 0, - (char *)&boot_params->edd_mbr_sig_buffer[0] - - (char *)&boot_params->_pad7[0]); - memset(&boot_params->_pad8[0], 0, - (char *)&boot_params->eddbuf[0] - - (char *)&boot_params->_pad8[0]); - memset(&boot_params->_pad9[0], 0, sizeof(boot_params->_pad9)); + static struct boot_params scratch; + char *bp_base = (char *)boot_params; + char *save_base = (char *)&scratch; + int i; + + const struct boot_params_to_save to_save[] = { + BOOT_PARAM_PRESERVE(screen_info), + BOOT_PARAM_PRESERVE(apm_bios_info), + BOOT_PARAM_PRESERVE(tboot_addr), + BOOT_PARAM_PRESERVE(ist_info), + BOOT_PARAM_PRESERVE(acpi_rsdp_addr), + BOOT_PARAM_PRESERVE(hd0_info), + BOOT_PARAM_PRESERVE(hd1_info), + BOOT_PARAM_PRESERVE(sys_desc_table), + BOOT_PARAM_PRESERVE(olpc_ofw_header), + BOOT_PARAM_PRESERVE(efi_info), + BOOT_PARAM_PRESERVE(alt_mem_k), + BOOT_PARAM_PRESERVE(scratch), + BOOT_PARAM_PRESERVE(e820_entries), + BOOT_PARAM_PRESERVE(eddbuf_entries), + BOOT_PARAM_PRESERVE(edd_mbr_sig_buf_entries), + BOOT_PARAM_PRESERVE(edd_mbr_sig_buffer), + BOOT_PARAM_PRESERVE(e820_table), + BOOT_PARAM_PRESERVE(eddbuf), + }; + + memset(&scratch, 0, sizeof(scratch)); + + for (i = 0; i < ARRAY_SIZE(to_save); i++) { + memcpy(save_base + to_save[i].start, + bp_base + to_save[i].start, to_save[i].len); + } + + memcpy(boot_params, save_base, sizeof(*boot_params)); } } -- 2.7.4 -- _______________________________________________ linux-yocto mailing list linux-yocto@yoctoproject.org https://lists.yoctoproject.org/listinfo/linux-yocto
