mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-12 13:55:32 +00:00
x86/boot: Save fields explicitly, zero out everything else
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 <tglx@linutronix.de> Suggested-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190731054627.5627-2-jhubbard@nvidia.com
This commit is contained in:
parent
5ed1c835ed
commit
a90118c445
1 changed files with 48 additions and 15 deletions
|
@ -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));
|
||||
}
|
||||
}
|
||||
|
||||
|
|
Loading…
Reference in a new issue