Commit a7d2c5cb authored by Christopher Friedt's avatar Christopher Friedt Committed by Fabio Baltieri
Browse files

posix: implement pthread_getguardsize() pthread_setguardsize() 

Implement pthread_getguardsize() and pthread_setguardsize().

pthread_getguardsize() and pthread_setguardsize() are required
by the POSIX_THREADS_EXT Option Group as detailed in Section
E.1 of IEEE-1003.1-2017. However, they were formerly part of
XSI_THREADS_EXT.

The XSI_THREADS_EXT Option Group was required for PSE51, PSE52,
PSE53, and PSE54 conformance.

Signed-off-by: default avatarChristopher Friedt <cfriedt@meta.com>
parent eb7e4bed

include/zephyr/posix/posix_types.h

+2 −0
Changes for include/zephyr/posix/posix_types.h: 2 added lines, 0 removed lines.
Original line number Diff line number Diff line
@@ -39,8 +39,10 @@ typedef unsigned long timer_t; 
struct pthread_attr {

	void *stack;

	uint16_t stacksize;

	uint16_t guardsize;

	int8_t priority;

	uint8_t schedpolicy: 2;

	uint8_t guardsize_msbit: 1;

	bool initialized: 1;

	bool cancelstate: 1;

	bool detachstate: 1;

include/zephyr/posix/pthread.h

+2 −0
Changes for include/zephyr/posix/pthread.h: 2 added lines, 0 removed lines.
Original line number Diff line number Diff line
@@ -428,7 +428,9 @@ static inline int pthread_rwlockattr_init(pthread_rwlockattr_t *attr) 
	return 0;

}



int pthread_attr_getguardsize(const pthread_attr_t *ZRESTRICT attr, size_t *ZRESTRICT guardsize);

int pthread_attr_getstacksize(const pthread_attr_t *attr, size_t *stacksize);

int pthread_attr_setguardsize(pthread_attr_t *attr, size_t guardsize);

int pthread_attr_setstacksize(pthread_attr_t *attr, size_t stacksize);

int pthread_attr_setschedpolicy(pthread_attr_t *attr, int policy);

int pthread_attr_getschedpolicy(const pthread_attr_t *attr, int *policy);

lib/posix/Kconfig.pthread

+13 −0
Changes for lib/posix/Kconfig.pthread: 13 added lines, 0 removed lines.
Original line number Diff line number Diff line
@@ -27,4 +27,17 @@ config PTHREAD_RECYCLER_DELAY_MS 
	  Note: this option should be considered temporary and will likely be

	  removed once a more synchronous solution is available.



config POSIX_PTHREAD_ATTR_GUARDSIZE_DEFAULT

	int "Default size of stack guard area"

	range 0 65536

	default 0

	help

	  This is the default amount of space to reserve at the overflow end of a

	  pthread stack. Since Zephyr already supports both software-based stack

	  protection (canaries) and hardware-based stack protection (MMU or MPU),

	  this is set to 0 by default. However, a conforming application would be

	  required to set this to PAGESIZE. Eventually, this option might

	  facilitate a more dynamic approach to guard areas (via software or

	  hardware) but for now it simply increases the size of thread stacks.



endif

lib/posix/pthread.c

+42 −2
Changes for lib/posix/pthread.c: 42 added lines, 2 removed lines.
Original line number Diff line number Diff line
@@ -50,6 +50,17 @@ static inline void __set_attr_stacksize(struct pthread_attr *attr, size_t size) 
	attr->stacksize = size - 1;

}



static inline size_t __get_attr_guardsize(const struct pthread_attr *attr)

{

	return (attr->guardsize_msbit * BIT(16)) | attr->guardsize;

}



static inline void __set_attr_guardsize(struct pthread_attr *attr, size_t size)

{

	attr->guardsize_msbit = size == PTHREAD_STACK_MAX;

	attr->guardsize = size & BIT_MASK(16);

}



struct __pthread_cleanup {

	void (*routine)(void *arg);

	void *arg;
@@ -85,8 +96,10 @@ static int pthread_concurrency; 
static const struct pthread_attr init_pthread_attrs = {

	.stack = NULL,

	.stacksize = 0,

	.guardsize = (BIT_MASK(16) & CONFIG_POSIX_PTHREAD_ATTR_GUARDSIZE_DEFAULT),

	.priority = DEFAULT_PTHREAD_PRIORITY,

	.schedpolicy = DEFAULT_PTHREAD_POLICY,

	.guardsize_msbit = (BIT(16) & CONFIG_POSIX_PTHREAD_ATTR_GUARDSIZE_DEFAULT),

	.initialized = true,

	.cancelstate = PTHREAD_CANCEL_ENABLE,

	.detachstate = PTHREAD_CREATE_JOINABLE,
@@ -253,7 +266,7 @@ int pthread_attr_setschedparam(pthread_attr_t *_attr, const struct sched_param * 
	int priority = schedparam->sched_priority;



	if (attr == NULL || !attr->initialized ||

	    is_posix_policy_prio_valid(priority, attr->schedpolicy == false)) {

	    !is_posix_policy_prio_valid(priority, attr->schedpolicy)) {

		LOG_ERR("Invalid pthread_attr_t or sched_param");

		return EINVAL;

	}
@@ -436,7 +449,8 @@ int pthread_create(pthread_t *th, const pthread_attr_t *_attr, void *(*threadrou 
		attr = &attr_storage;

		BUILD_ASSERT(DYNAMIC_STACK_SIZE <= PTHREAD_STACK_MAX);

		__set_attr_stacksize(attr, DYNAMIC_STACK_SIZE);

		attr->stack = k_thread_stack_alloc(__get_attr_stacksize(attr),

		attr->stack = k_thread_stack_alloc(__get_attr_stacksize(attr) +

							   __get_attr_guardsize(attr),

						   k_is_user_context() ? K_USER : 0);

		if (attr->stack == NULL) {

			LOG_ERR("Unable to allocate stack of size %u", DYNAMIC_STACK_SIZE);
@@ -988,6 +1002,32 @@ int pthread_attr_getstack(const pthread_attr_t *_attr, void **stackaddr, size_t 
	return 0;

}



int pthread_attr_getguardsize(const pthread_attr_t *ZRESTRICT _attr, size_t *ZRESTRICT guardsize)

{

	struct pthread_attr *const attr = (struct pthread_attr *)_attr;



	if (attr == NULL || guardsize == NULL || !attr->initialized) {

		return EINVAL;

	}



	*guardsize = __get_attr_guardsize(attr);



	return 0;

}



int pthread_attr_setguardsize(pthread_attr_t *_attr, size_t guardsize)

{

	struct pthread_attr *const attr = (struct pthread_attr *)_attr;



	if (attr == NULL || !attr->initialized || guardsize > PTHREAD_STACK_MAX) {

		return EINVAL;

	}



	__set_attr_guardsize(attr, guardsize);



	return 0;

}



/**

 * @brief Get thread attributes object scheduling parameters.

 *

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