"acpi_mask_gpe=" kernel parameter is introduced to mask one or more GPEs at boot stage, to prevent GPE flooding. Currently, a maximum of 128 GPEs (from GPE 0x00 to GPE 0x7f) are allowed to be masked by this kernel parameter, but only one u64 variant is used as the bitmap for the masked GPEs in kernel. This is bogus and makes some GPEs masked unexpected when masking a GPE larger than 0x40. For example, with CONFIG_UBSAN=y, when "acpi_mask_gpe=0x6f" is parsed, we get [ 0.039669] ACPI: Masking GPE 0x2f. [ 0.039681] ================================================================================ [ 0.039684] UBSAN: Undefined behaviour in drivers/acpi/sysfs.c:846:33 [ 0.039688] shift exponent 64 is too large for 64-bit type 'long long unsigned int' [ 0.039692] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.14.0-UBSAN-check+ #37 [ 0.039695] Hardware name: Microsoft Corporation Surface Pro 4/Surface Pro 4, BIOS 106.1281.768 08/01/2016 [ 0.039698] Call Trace: [ 0.039704] dump_stack+0x64/0x91 [ 0.039709] ubsan_epilogue+0xd/0x40 [ 0.039712] __ubsan_handle_shift_out_of_bounds+0xf6/0x140 [ 0.039716] ? do_syscall_64+0x1e6/0x760 [ 0.039720] ? acpi_ev_mask_gpe+0x141/0x14c [ 0.039724] acpi_gpe_apply_masked_gpes+0x41/0x8a [ 0.039727] ? acpi_gpe_apply_masked_gpes+0x41/0x8a [ 0.039731] acpi_scan_init+0x14d/0x2df [ 0.039734] acpi_init+0x32d/0x379 [ 0.039737] ? acpi_sleep_proc_init+0x2a/0x2a [ 0.039740] do_one_initcall+0x116/0x1d0 [ 0.039743] kernel_init_freeable+0x304/0x39a [ 0.039746] ? rest_init+0xf0/0xf0 [ 0.039749] kernel_init+0xf/0x120 [ 0.039752] ? rest_init+0xf0/0xf0 [ 0.039756] ret_from_fork+0x25/0x30 [ 0.039758] ================================================================================ [ 0.039762] ACPI: Masking GPE 0x6f. Fix this by using the bitmap helper, for declaring, testing and setting the bitmap. Link: https://bugzilla.kernel.org/show_bug.cgi?id=198481 Reported-and-tested-by: Paul Menzel <pmenzel+bugzilla.kernel.org@xxxxxxxxxxxxx> Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx> Cc: 4.10+ <stable@xxxxxxxxxxxxxxx> # 4.10+ --- drivers/acpi/sysfs.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/acpi/sysfs.c b/drivers/acpi/sysfs.c index 0fd57bf..f0d1163 100644 --- a/drivers/acpi/sysfs.c +++ b/drivers/acpi/sysfs.c @@ -820,7 +820,7 @@ static ssize_t counter_set(struct kobject *kobj, */ #define ACPI_MASKABLE_GPE_MAX 0x80 -static u64 __initdata acpi_masked_gpes; +static __initdata DECLARE_BITMAP(acpi_masked_gpes, ACPI_MASKABLE_GPE_MAX); static int __init acpi_gpe_set_masked_gpes(char *val) { @@ -828,7 +828,7 @@ static int __init acpi_gpe_set_masked_gpes(char *val) if (kstrtou8(val, 0, &gpe) || gpe > ACPI_MASKABLE_GPE_MAX) return -EINVAL; - acpi_masked_gpes |= ((u64)1<<gpe); + set_bit(gpe, acpi_masked_gpes); return 1; } @@ -843,7 +843,7 @@ void __init acpi_gpe_apply_masked_gpes(void) for (gpe = 0; gpe < min_t(u8, ACPI_MASKABLE_GPE_MAX, acpi_current_gpe_count); gpe++) { - if (acpi_masked_gpes & ((u64)1<<gpe)) { + if (test_bit(gpe, acpi_masked_gpes)) { status = acpi_get_gpe_device(gpe, &handle); if (ACPI_SUCCESS(status)) { pr_info("Masking GPE 0x%x.\n", gpe); -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
