OpenCloudOS-Kernel/drivers/cpuidle
C Cheng 3f0a747281 cpuidle: Avoid potential overflow in integer multiplication
[ Upstream commit 88390dd788db485912ee7f9a8d3d56fc5265d52f ]

In detail:

In C language, when you perform a multiplication operation, if
both operands are of int type, the multiplication operation is
performed on the int type, and then the result is converted to
the target type. This means that if the product of int type
multiplication exceeds the range that int type can represent,
an overflow will occur even if you store the result in a
variable of int64_t type.

For a multiplication of two int values, it is better to use
mul_u32_u32() rather than s->exit_latency_ns = s->exit_latency *
NSEC_PER_USEC to avoid potential overflow happenning.

Signed-off-by: C Cheng <C.Cheng@mediatek.com>
Signed-off-by: Bo Ye <bo.ye@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
[ rjw: New subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-13 13:07:29 +02:00
..
governors cpuidle: teo: Avoid unnecessary variable assignments 2023-08-23 18:25:04 +02:00
Kconfig cpuidle-haltpoll: select haltpoll governor 2023-01-13 20:50:46 +01:00
Kconfig.arm cpuidle: psci: Do not suspend topology CPUs on PREEMPT_RT 2023-02-13 17:15:42 +01:00
Kconfig.mips treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Kconfig.powerpc treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Kconfig.riscv cpuidle: Add RISC-V SBI CPU idle driver 2022-03-10 09:29:51 -08:00
Makefile cpuidle: Add RISC-V SBI CPU idle driver 2022-03-10 09:29:51 -08:00
coupled.c cpuidle: coupled: Drop duplicate word from a comment 2022-08-31 20:54:01 +02:00
cpuidle-arm.c cpuidle, arch: Mark all ct_cpuidle_enter() callers __cpuidle 2023-01-13 11:48:17 +01:00
cpuidle-at91.c treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_56.RULE (part 2) 2022-06-10 14:51:35 +02:00
cpuidle-big_little.c cpuidle, arch: Mark all ct_cpuidle_enter() callers __cpuidle 2023-01-13 11:48:17 +01:00
cpuidle-calxeda.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201 2019-05-30 11:29:52 -07:00
cpuidle-clps711x.c cpuidle: clps711x: convert to devm_platform_ioremap_resource() 2019-12-20 10:04:27 +01:00
cpuidle-cps.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
cpuidle-exynos.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
cpuidle-haltpoll.c cpuidle: haltpoll: Do not enable interrupts when entering idle 2024-01-25 15:35:15 -08:00
cpuidle-kirkwood.c treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_56.RULE (part 2) 2022-06-10 14:51:35 +02:00
cpuidle-mvebu-v7.c cpuidle: mvebu: Fix duplicate flags assignment 2023-01-18 12:03:54 +01:00
cpuidle-powernv.c powerpc/cpuidle: Set CPUIDLE_FLAG_POLLING for snooze state 2022-12-06 23:18:19 +11:00
cpuidle-psci-domain.c cpuidle: psci: Move enabling OSI mode after power domains creation 2023-08-08 16:07:01 +02:00
cpuidle-psci.c cpuidle: Adjust includes to remove of_device.h 2023-04-13 17:46:35 -05:00
cpuidle-psci.h cpuidle: Factor-out power domain related code from PSCI domain driver 2022-03-10 09:29:44 -08:00
cpuidle-pseries.c powerpc/pseries: Rework lppaca_shared_proc() to avoid DEBUG_PREEMPT 2023-08-24 22:33:17 +10:00
cpuidle-qcom-spm.c cpuidle: Adjust includes to remove of_device.h 2023-04-13 17:46:35 -05:00
cpuidle-riscv-sbi.c RISC-V: Align SBI probe implementation with spec 2023-04-29 13:04:50 -07:00
cpuidle-tegra.c cpuidle, arch: Mark all ct_cpuidle_enter() callers __cpuidle 2023-01-13 11:48:17 +01:00
cpuidle-ux500.c mfd/cpuidle: ux500: Rename driver symbol 2021-08-16 13:42:34 +01:00
cpuidle-zynq.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201 2019-05-30 11:29:52 -07:00
cpuidle.c cpuidle: Use local_clock_noinstr() 2023-06-05 21:11:09 +02:00
cpuidle.h cpuidle: move to use bus_get_dev_root() 2023-03-22 20:25:23 +01:00
driver.c cpuidle: Avoid potential overflow in integer multiplication 2024-04-13 13:07:29 +02:00
dt_idle_genpd.c cpuidle: dt_idle_genpd: Add helper function to remove genpd topology 2023-08-08 16:06:20 +02:00
dt_idle_genpd.h cpuidle: dt_idle_genpd: Add helper function to remove genpd topology 2023-08-08 16:06:20 +02:00
dt_idle_states.c cpuidle: Adjust includes to remove of_device.h 2023-04-13 17:46:35 -05:00
dt_idle_states.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
governor.c cpuidle: Remove redundant check in cpuidle_switch_governor() 2022-09-03 20:14:51 +02:00
poll_state.c cpuidle: Use local_clock_noinstr() 2023-06-05 21:11:09 +02:00
sysfs.c cpuidle: move to use bus_get_dev_root() 2023-03-22 20:25:23 +01:00