/*
* Copyright (c) 2014 Apple Inc. All rights reserved.
*
* @APPLE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this
* file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_LICENSE_HEADER_END@
*/
#include <sys/stackshot.h>
#include <mach/mach.h>
#include <mach/mach_vm.h>
#include <stdint.h>
#include <stdlib.h>
#include <errno.h>
/*
* System call entry point
*/
int __stack_snapshot_with_config(int stackshot_config_version, user_addr_t stackshot_config, size_t stackshot_config_size);
/*
* stackshot_config_create: create and initialize the arguments for a stackshot
*
* Outputs: NULL if malloc fails
* a pointer to a new stackshot_config_t on success
*/
stackshot_config_t *
stackshot_config_create(void)
{
stackshot_config_t *s_config;
s_config = malloc(sizeof(stackshot_config_t));
if (s_config == NULL) {
return NULL;
}
s_config->sc_pid = -1;
s_config->sc_flags = 0;
s_config->sc_delta_timestamp = 0;
s_config->sc_buffer = 0;
s_config->sc_size = 0;
s_config->sc_pagetable_mask = 0;
return s_config;
}
/*
* stackshot_config_set_pid: set the PID to be traced
*
* Inputs: stackshot_config - a pointer to the stackshot_config_t we want to update
* pid - process id of process to be traced, or -1 for the entire system
*
* Outputs: EINVAL if the passed stackshot_config pointer is NULL
* 0 on success
*/
int
stackshot_config_set_pid(stackshot_config_t *stackshot_config, int pid)
{
stackshot_config_t *s_config;
if (stackshot_config == NULL) {
return EINVAL;
}
s_config = (stackshot_config_t *) stackshot_config;
s_config->sc_pid = pid;
return 0;
}
/*
* stackshot_config_set_flags: set the flags to be passed for the stackshot
*
* Inputs: stackshot_config - a pointer to the stackshot_config_t we want to update
* flags - flags to pass to stackshot
*
* Outputs: EINVAL if the passed stackshot_config pointer is NULL
* 0 on success
*/
int
stackshot_config_set_flags(stackshot_config_t *stackshot_config, uint64_t flags)
{
stackshot_config_t *s_config;
if (stackshot_config == NULL) {
return EINVAL;
}
s_config = (stackshot_config_t *) stackshot_config;
s_config->sc_flags = flags;
return 0;
}
/*
* stackshot_capture_with_config: take a stackshot with the provided config
*
* Inputs: stackshot_config - a pointer to the stackshot_config_t we want to use
*
* Outputs: EINVAL if the passed stackshot_config pointer is NULL, a caller is trying
* to reuse a config without deallocating its buffer or if there is a
* problem with the arguments
* EFAULT if there was a problem with accessing the arguments from the kernel
* EPERM if the caller is not privileged
* ENOTSUP if the caller is passing a stackshot config version that is not
* supported by the kernel (indicates libsyscall:kernel mismatch),
* or if the caller is requesting unsupported flags
* ENOMEM if the kernel is unable to allocate memory
* ENOSPC if the caller doesn't have enough space in their address space for
* the kernel to remap the buffer
* ENOENT if the caller is requesting an existing buffer that doesn't exist
* or the target PID isn't found
* 0 on success
*/
int
stackshot_capture_with_config(stackshot_config_t *stackshot_config)
{
int ret;
stackshot_config_t *s_config;
if (stackshot_config == NULL) {
return EINVAL;
}
s_config = (stackshot_config_t *) stackshot_config;
if (s_config->sc_buffer != 0) {
return EINVAL;
}
s_config->sc_out_buffer_addr = (uintptr_t)&s_config->sc_buffer;
s_config->sc_out_size_addr = (uintptr_t)&s_config->sc_size;
ret = __stack_snapshot_with_config(STACKSHOT_CONFIG_TYPE, (uintptr_t)s_config, sizeof(stackshot_config_t));
if (ret != 0) {
ret = errno;
s_config->sc_buffer = 0;
s_config->sc_size = 0;
}
return ret;
}
/*
* stackshot_config_get_stackshot_buffer: get a pointer to the buffer containing the stackshot
*
* Inputs: stackshot_config - a pointer to a stackshot_config_t
*
* Outputs: NULL if the passed stackshot_config is NULL or if its buffer is NULL
* a pointer to the buffer containing the stackshot on success
*/
void *
stackshot_config_get_stackshot_buffer(stackshot_config_t *stackshot_config)
{
stackshot_config_t *s_config;
if (stackshot_config == NULL) {
return NULL;
}
s_config = (stackshot_config_t *) stackshot_config;
return (void *)s_config->sc_buffer;
}
/*
* stackshot_config_get_stackshot_size: get the size of the stackshot buffer
*
* Inputs: stackshot_config - a pointer to a stackshot_config_t
*
* Outputs: -1 if the passed stackshot config is NULL or there is no buffer
* the length of the stackshot buffer on success
*/
uint32_t
stackshot_config_get_stackshot_size(stackshot_config_t * stackshot_config)
{
if (stackshot_config == NULL || (void *)stackshot_config->sc_buffer == NULL) {
return -1;
}
return stackshot_config->sc_size;
}
/*
* stackshot_config_set_size_hint: set the size of the stackshot buffer
*
* Inputs: stackshot_config - a pointer to a stackshot_config_t
* suggested_size - hint for size allocation of stackshot
*
* Outputs: -1 if the passed stackshot config is NULL or there is existing stackshot buffer set.
* the length of the stackshot buffer on success.
*/
int
stackshot_config_set_size_hint(stackshot_config_t *stackshot_config, uint32_t suggested_size)
{
if (stackshot_config == NULL || (void *)stackshot_config->sc_buffer != NULL) {
return -1;
}
stackshot_config->sc_size = suggested_size;
return 0;
}
/*
* stackshot_config_set_delta_timestamp: set the timestamp to use as the basis for the delta stackshot
*
* This timestamp will be used along with STACKSHOT_COLLECT_DELTA_SNAPSHOT flag to collect delta stackshots
*
* Inputs: stackshot_config - a pointer to a stackshot_config_t
* delta_timestamp - timestamp in MachAbsoluteTime units to be used as the basis for a delta stackshot
*
* Outputs: -1 if the passed stackshot config is NULL or there is existing stackshot buffer set.
* 0 on success
*/
int
stackshot_config_set_delta_timestamp(stackshot_config_t *stackshot_config, uint64_t delta_timestamp)
{
if (stackshot_config == NULL || (void *)stackshot_config->sc_buffer != NULL) {
return -1;
}
stackshot_config->sc_delta_timestamp = delta_timestamp;
return 0;
}
/*
* stackshot_config_set_pagetable_mask: set the level mask for pagetable dumping
*
* Each bit of the mask corresponds to a level in the paging structure. Bit 0
* corresponds to Level 0, bit 1 to level 1, and so on. It is undefined what
* happens when a bit is set that's higher than the current maximum level of
* pagetable structures.
*
* When using this setter, you must also pass STACKSHOT_PAGE_TABLES as a flag
* before invoking stackshot, otherwise this setter is a no-operation.
*
* Inputs: stackshot_config - a pointer to a stackshot_config_t
* level_mask - the pagetable level mask, as described above
*
* Outputs: -1 if the passed stackshot config is NULL or there is existing stackshot buffer set.
* 0 on success
*/
int
stackshot_config_set_pagetable_mask(stackshot_config_t *stackshot_config, uint32_t pagetable_mask)
{
if (stackshot_config == NULL || (void *)stackshot_config->sc_buffer != NULL) {
return -1;
}
stackshot_config->sc_pagetable_mask = pagetable_mask;
return 0;
}
/*
* stackshot_config_dealloc_buffer: dealloc the stackshot buffer and reset the size so that a
* stackshot_config_t can be used again
*
* Inputs: stackshot_config - a pointer to a stackshot_config_t
*
* Outputs: EINVAL if the passed stackshot_config is NULL or if its buffer is NULL
* 0 otherwise
*/
int
stackshot_config_dealloc_buffer(stackshot_config_t *stackshot_config)
{
stackshot_config_t *s_config;
if (stackshot_config == NULL) {
return EINVAL;
}
s_config = (stackshot_config_t *) stackshot_config;
if (s_config->sc_size && s_config->sc_buffer) {
mach_vm_deallocate(mach_task_self(), (mach_vm_offset_t)s_config->sc_buffer, (mach_vm_size_t)s_config->sc_size);
}
s_config->sc_buffer = 0;
s_config->sc_size = 0;
return 0;
}
/*
* stackshot_config_dealloc: dealloc the stackshot buffer and the stackshot config
*
* Inputs: stackshot_config - a pointer to a stackshot_config_t
*
* Outputs: EINVAL if the passed stackshot_cofnig is NULL
* 0 otherwise
*/
int
stackshot_config_dealloc(stackshot_config_t *stackshot_config)
{
stackshot_config_t *s_config;
if (stackshot_config == NULL) {
return EINVAL;
}
s_config = (stackshot_config_t *) stackshot_config;
if (s_config->sc_size && s_config->sc_buffer) {
mach_vm_deallocate(mach_task_self(), (mach_vm_offset_t)s_config->sc_buffer, (mach_vm_size_t)s_config->sc_size);
}
s_config->sc_buffer = 0;
s_config->sc_size = 0;
free(s_config);
return 0;
}