Date: Sun, 18 Jun 2017 17:52:45 +0800 From: Jia-Ju Bai <baijiaju1990@163.com> Cc: freebsd-drivers@freebsd.org, freebsd-acpi@freebsd.org, Jia-Ju Bai <baijiaju1990@163.com> Subject: [Bug 220096][PATCH] acpi_thermal: Fix a possible sleep-under-mutex bug in acpi_tz_thread Message-ID: <20170618095245.40693-1-baijiaju1990@163.com>
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The driver may sleep under a mutex, and the code path is: acpi_tz_thread [line 992: acquire the mutex] acpi_tz_thread [line 993] acpi_tz_thread [line 1003] acpi_tz_thread [line 1004] (msleep is excuted) acpi_tz_thread [line 1008] acpi_tz_thread [line 970] acpi_tz_thread [line 971] acpi_tz_thread [line 975] malloc(M_WAITOK) [line 976] The possible fix of this bug is to replace "M_WAITOK" in malloc with "M_NOWAIT". This bug is found by a static analysis tool written by myself, and it is checked by my review of the FreeBSD code. Signed-off-by: Jia-Ju Bai <baijiaju1990@163.com> --- sys/dev/acpica/acpi_thermal.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/sys/dev/acpica/acpi_thermal.c b/sys/dev/acpica/acpi_thermal.c index b2b2a13aa88..fb9f44b5711 100644 --- a/sys/dev/acpica/acpi_thermal.c +++ b/sys/dev/acpica/acpi_thermal.c @@ -974,7 +974,7 @@ acpi_tz_thread(void *arg) } devclass_get_devices(acpi_tz_devclass, &devs, &devcount); sc = malloc(sizeof(struct acpi_tz_softc *) * devcount, M_TEMP, - M_WAITOK | M_ZERO); + M_NOWAIT | M_ZERO); for (i = 0; i < devcount; i++) sc[i] = device_get_softc(devs[i]); } -- 2.13.0
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