1*6954e415SSteven Rostedt (VMware) // SPDX-License-Identifier: GPL-2.0 2*6954e415SSteven Rostedt (VMware) /* 3*6954e415SSteven Rostedt (VMware) * Copyright (C) 2021 VMware Inc, Steven Rostedt <rostedt@goodmis.org> 4*6954e415SSteven Rostedt (VMware) */ 5*6954e415SSteven Rostedt (VMware) #include <linux/vmalloc.h> 6*6954e415SSteven Rostedt (VMware) #include <linux/slab.h> 7*6954e415SSteven Rostedt (VMware) #include "trace.h" 8*6954e415SSteven Rostedt (VMware) 9*6954e415SSteven Rostedt (VMware) /** 10*6954e415SSteven Rostedt (VMware) * trace_pid_list_is_set - test if the pid is set in the list 11*6954e415SSteven Rostedt (VMware) * @pid_list: The pid list to test 12*6954e415SSteven Rostedt (VMware) * @pid: The pid to to see if set in the list. 13*6954e415SSteven Rostedt (VMware) * 14*6954e415SSteven Rostedt (VMware) * Tests if @pid is is set in the @pid_list. This is usually called 15*6954e415SSteven Rostedt (VMware) * from the scheduler when a task is scheduled. Its pid is checked 16*6954e415SSteven Rostedt (VMware) * if it should be traced or not. 17*6954e415SSteven Rostedt (VMware) * 18*6954e415SSteven Rostedt (VMware) * Return true if the pid is in the list, false otherwise. 19*6954e415SSteven Rostedt (VMware) */ 20*6954e415SSteven Rostedt (VMware) bool trace_pid_list_is_set(struct trace_pid_list *pid_list, unsigned int pid) 21*6954e415SSteven Rostedt (VMware) { 22*6954e415SSteven Rostedt (VMware) /* 23*6954e415SSteven Rostedt (VMware) * If pid_max changed after filtered_pids was created, we 24*6954e415SSteven Rostedt (VMware) * by default ignore all pids greater than the previous pid_max. 25*6954e415SSteven Rostedt (VMware) */ 26*6954e415SSteven Rostedt (VMware) if (pid >= pid_list->pid_max) 27*6954e415SSteven Rostedt (VMware) return false; 28*6954e415SSteven Rostedt (VMware) 29*6954e415SSteven Rostedt (VMware) return test_bit(pid, pid_list->pids); 30*6954e415SSteven Rostedt (VMware) } 31*6954e415SSteven Rostedt (VMware) 32*6954e415SSteven Rostedt (VMware) /** 33*6954e415SSteven Rostedt (VMware) * trace_pid_list_set - add a pid to the list 34*6954e415SSteven Rostedt (VMware) * @pid_list: The pid list to add the @pid to. 35*6954e415SSteven Rostedt (VMware) * @pid: The pid to add. 36*6954e415SSteven Rostedt (VMware) * 37*6954e415SSteven Rostedt (VMware) * Adds @pid to @pid_list. This is usually done explicitly by a user 38*6954e415SSteven Rostedt (VMware) * adding a task to be traced, or indirectly by the fork function 39*6954e415SSteven Rostedt (VMware) * when children should be traced and a task's pid is in the list. 40*6954e415SSteven Rostedt (VMware) * 41*6954e415SSteven Rostedt (VMware) * Return 0 on success, negative otherwise. 42*6954e415SSteven Rostedt (VMware) */ 43*6954e415SSteven Rostedt (VMware) int trace_pid_list_set(struct trace_pid_list *pid_list, unsigned int pid) 44*6954e415SSteven Rostedt (VMware) { 45*6954e415SSteven Rostedt (VMware) /* Sorry, but we don't support pid_max changing after setting */ 46*6954e415SSteven Rostedt (VMware) if (pid >= pid_list->pid_max) 47*6954e415SSteven Rostedt (VMware) return -EINVAL; 48*6954e415SSteven Rostedt (VMware) 49*6954e415SSteven Rostedt (VMware) set_bit(pid, pid_list->pids); 50*6954e415SSteven Rostedt (VMware) 51*6954e415SSteven Rostedt (VMware) return 0; 52*6954e415SSteven Rostedt (VMware) } 53*6954e415SSteven Rostedt (VMware) 54*6954e415SSteven Rostedt (VMware) /** 55*6954e415SSteven Rostedt (VMware) * trace_pid_list_clear - remove a pid from the list 56*6954e415SSteven Rostedt (VMware) * @pid_list: The pid list to remove the @pid from. 57*6954e415SSteven Rostedt (VMware) * @pid: The pid to remove. 58*6954e415SSteven Rostedt (VMware) * 59*6954e415SSteven Rostedt (VMware) * Removes @pid from @pid_list. This is usually done explicitly by a user 60*6954e415SSteven Rostedt (VMware) * removing tasks from tracing, or indirectly by the exit function 61*6954e415SSteven Rostedt (VMware) * when a task that is set to be traced exits. 62*6954e415SSteven Rostedt (VMware) * 63*6954e415SSteven Rostedt (VMware) * Return 0 on success, negative otherwise. 64*6954e415SSteven Rostedt (VMware) */ 65*6954e415SSteven Rostedt (VMware) int trace_pid_list_clear(struct trace_pid_list *pid_list, unsigned int pid) 66*6954e415SSteven Rostedt (VMware) { 67*6954e415SSteven Rostedt (VMware) /* Sorry, but we don't support pid_max changing after setting */ 68*6954e415SSteven Rostedt (VMware) if (pid >= pid_list->pid_max) 69*6954e415SSteven Rostedt (VMware) return -EINVAL; 70*6954e415SSteven Rostedt (VMware) 71*6954e415SSteven Rostedt (VMware) clear_bit(pid, pid_list->pids); 72*6954e415SSteven Rostedt (VMware) 73*6954e415SSteven Rostedt (VMware) return 0; 74*6954e415SSteven Rostedt (VMware) } 75*6954e415SSteven Rostedt (VMware) 76*6954e415SSteven Rostedt (VMware) /** 77*6954e415SSteven Rostedt (VMware) * trace_pid_list_next - return the next pid in the list 78*6954e415SSteven Rostedt (VMware) * @pid_list: The pid list to examine. 79*6954e415SSteven Rostedt (VMware) * @pid: The pid to start from 80*6954e415SSteven Rostedt (VMware) * @next: The pointer to place the pid that is set starting from @pid. 81*6954e415SSteven Rostedt (VMware) * 82*6954e415SSteven Rostedt (VMware) * Looks for the next consecutive pid that is in @pid_list starting 83*6954e415SSteven Rostedt (VMware) * at the pid specified by @pid. If one is set (including @pid), then 84*6954e415SSteven Rostedt (VMware) * that pid is placed into @next. 85*6954e415SSteven Rostedt (VMware) * 86*6954e415SSteven Rostedt (VMware) * Return 0 when a pid is found, -1 if there are no more pids included. 87*6954e415SSteven Rostedt (VMware) */ 88*6954e415SSteven Rostedt (VMware) int trace_pid_list_next(struct trace_pid_list *pid_list, unsigned int pid, 89*6954e415SSteven Rostedt (VMware) unsigned int *next) 90*6954e415SSteven Rostedt (VMware) { 91*6954e415SSteven Rostedt (VMware) pid = find_next_bit(pid_list->pids, pid_list->pid_max, pid); 92*6954e415SSteven Rostedt (VMware) 93*6954e415SSteven Rostedt (VMware) if (pid < pid_list->pid_max) { 94*6954e415SSteven Rostedt (VMware) *next = pid; 95*6954e415SSteven Rostedt (VMware) return 0; 96*6954e415SSteven Rostedt (VMware) } 97*6954e415SSteven Rostedt (VMware) return -1; 98*6954e415SSteven Rostedt (VMware) } 99*6954e415SSteven Rostedt (VMware) 100*6954e415SSteven Rostedt (VMware) /** 101*6954e415SSteven Rostedt (VMware) * trace_pid_list_first - return the first pid in the list 102*6954e415SSteven Rostedt (VMware) * @pid_list: The pid list to examine. 103*6954e415SSteven Rostedt (VMware) * @pid: The pointer to place the pid first found pid that is set. 104*6954e415SSteven Rostedt (VMware) * 105*6954e415SSteven Rostedt (VMware) * Looks for the first pid that is set in @pid_list, and places it 106*6954e415SSteven Rostedt (VMware) * into @pid if found. 107*6954e415SSteven Rostedt (VMware) * 108*6954e415SSteven Rostedt (VMware) * Return 0 when a pid is found, -1 if there are no pids set. 109*6954e415SSteven Rostedt (VMware) */ 110*6954e415SSteven Rostedt (VMware) int trace_pid_list_first(struct trace_pid_list *pid_list, unsigned int *pid) 111*6954e415SSteven Rostedt (VMware) { 112*6954e415SSteven Rostedt (VMware) unsigned int first; 113*6954e415SSteven Rostedt (VMware) 114*6954e415SSteven Rostedt (VMware) first = find_first_bit(pid_list->pids, pid_list->pid_max); 115*6954e415SSteven Rostedt (VMware) 116*6954e415SSteven Rostedt (VMware) if (first < pid_list->pid_max) { 117*6954e415SSteven Rostedt (VMware) *pid = first; 118*6954e415SSteven Rostedt (VMware) return 0; 119*6954e415SSteven Rostedt (VMware) } 120*6954e415SSteven Rostedt (VMware) return -1; 121*6954e415SSteven Rostedt (VMware) } 122*6954e415SSteven Rostedt (VMware) 123*6954e415SSteven Rostedt (VMware) /** 124*6954e415SSteven Rostedt (VMware) * trace_pid_list_alloc - create a new pid_list 125*6954e415SSteven Rostedt (VMware) * 126*6954e415SSteven Rostedt (VMware) * Allocates a new pid_list to store pids into. 127*6954e415SSteven Rostedt (VMware) * 128*6954e415SSteven Rostedt (VMware) * Returns the pid_list on success, NULL otherwise. 129*6954e415SSteven Rostedt (VMware) */ 130*6954e415SSteven Rostedt (VMware) struct trace_pid_list *trace_pid_list_alloc(void) 131*6954e415SSteven Rostedt (VMware) { 132*6954e415SSteven Rostedt (VMware) struct trace_pid_list *pid_list; 133*6954e415SSteven Rostedt (VMware) 134*6954e415SSteven Rostedt (VMware) pid_list = kmalloc(sizeof(*pid_list), GFP_KERNEL); 135*6954e415SSteven Rostedt (VMware) if (!pid_list) 136*6954e415SSteven Rostedt (VMware) return NULL; 137*6954e415SSteven Rostedt (VMware) 138*6954e415SSteven Rostedt (VMware) pid_list->pid_max = READ_ONCE(pid_max); 139*6954e415SSteven Rostedt (VMware) 140*6954e415SSteven Rostedt (VMware) pid_list->pids = vzalloc((pid_list->pid_max + 7) >> 3); 141*6954e415SSteven Rostedt (VMware) if (!pid_list->pids) { 142*6954e415SSteven Rostedt (VMware) kfree(pid_list); 143*6954e415SSteven Rostedt (VMware) return NULL; 144*6954e415SSteven Rostedt (VMware) } 145*6954e415SSteven Rostedt (VMware) return pid_list; 146*6954e415SSteven Rostedt (VMware) } 147*6954e415SSteven Rostedt (VMware) 148*6954e415SSteven Rostedt (VMware) /** 149*6954e415SSteven Rostedt (VMware) * trace_pid_list_free - Frees an allocated pid_list. 150*6954e415SSteven Rostedt (VMware) * 151*6954e415SSteven Rostedt (VMware) * Frees the memory for a pid_list that was allocated. 152*6954e415SSteven Rostedt (VMware) */ 153*6954e415SSteven Rostedt (VMware) void trace_pid_list_free(struct trace_pid_list *pid_list) 154*6954e415SSteven Rostedt (VMware) { 155*6954e415SSteven Rostedt (VMware) if (!pid_list) 156*6954e415SSteven Rostedt (VMware) return; 157*6954e415SSteven Rostedt (VMware) 158*6954e415SSteven Rostedt (VMware) vfree(pid_list->pids); 159*6954e415SSteven Rostedt (VMware) kfree(pid_list); 160*6954e415SSteven Rostedt (VMware) } 161