From e4842c451d2fcb20d4e7734a423b4dda17c5e79b Mon Sep 17 00:00:00 2001 From: jhb Date: Mon, 15 Aug 2016 21:10:41 +0000 Subject: MFC 302900,302902,302921,303461,304009: Add a mask of optional ptrace() events. 302900: Add a test for user signal delivery. This test verifies we get the correct ptrace event details when a signal is posted to a traced process from userland. 302902: Add a mask of optional ptrace() events. ptrace() now stores a mask of optional events in p_ptevents. Currently this mask is a single integer, but it can be expanded into an array of integers in the future. Two new ptrace requests can be used to manipulate the event mask: PT_GET_EVENT_MASK fetches the current event mask and PT_SET_EVENT_MASK sets the current event mask. The current set of events include: - PTRACE_EXEC: trace calls to execve(). - PTRACE_SCE: trace system call entries. - PTRACE_SCX: trace syscam call exits. - PTRACE_FORK: trace forks and auto-attach to new child processes. - PTRACE_LWP: trace LWP events. The S_PT_SCX and S_PT_SCE events in the procfs p_stops flags have been replaced by PTRACE_SCE and PTRACE_SCX. PTRACE_FORK replaces P_FOLLOW_FORK and PTRACE_LWP replaces P2_LWP_EVENTS. The PT_FOLLOW_FORK and PT_LWP_EVENTS ptrace requests remain for compatibility but now simply toggle corresponding flags in the event mask. While here, document that PT_SYSCALL, PT_TO_SCE, and PT_TO_SCX both modify the event mask and continue the traced process. 302921: Rename PTRACE_SYSCALL to LINUX_PTRACE_SYSCALL. 303461: Note that not all optional ptrace events use SIGTRAP. New child processes attached due to PTRACE_FORK use SIGSTOP instead of SIGTRAP. All other ptrace events use SIGTRAP. 304009: Remove description of P_FOLLOWFORK as this flag was removed. --- sys/kern/sys_process.c | 77 +++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 60 insertions(+), 17 deletions(-) (limited to 'sys/kern/sys_process.c') diff --git a/sys/kern/sys_process.c b/sys/kern/sys_process.c index af71ea8..f1477ce 100644 --- a/sys/kern/sys_process.c +++ b/sys/kern/sys_process.c @@ -586,6 +586,7 @@ sys_ptrace(struct thread *td, struct ptrace_args *uap) struct ptrace_lwpinfo32 pl32; struct ptrace_vm_entry32 pve32; #endif + int ptevents; } r; void *addr; int error = 0; @@ -600,6 +601,7 @@ sys_ptrace(struct thread *td, struct ptrace_args *uap) AUDIT_ARG_VALUE(uap->data); addr = &r; switch (uap->req) { + case PT_GET_EVENT_MASK: case PT_GETREGS: case PT_GETFPREGS: case PT_GETDBREGS: @@ -614,6 +616,12 @@ sys_ptrace(struct thread *td, struct ptrace_args *uap) case PT_SETDBREGS: error = COPYIN(uap->addr, &r.dbreg, sizeof r.dbreg); break; + case PT_SET_EVENT_MASK: + if (uap->data != sizeof(r.ptevents)) + error = EINVAL; + else + error = copyin(uap->addr, &r.ptevents, uap->data); + break; case PT_IO: error = COPYIN(uap->addr, &r.piod, sizeof r.piod); break; @@ -647,7 +655,12 @@ sys_ptrace(struct thread *td, struct ptrace_args *uap) case PT_GETDBREGS: error = COPYOUT(&r.dbreg, uap->addr, sizeof r.dbreg); break; + case PT_GET_EVENT_MASK: + /* NB: The size in uap->data is validated in kern_ptrace(). */ + error = copyout(&r.ptevents, uap->addr, uap->data); + break; case PT_LWPINFO: + /* NB: The size in uap->data is validated in kern_ptrace(). */ error = copyout(&r.pl, uap->addr, uap->data); break; } @@ -711,6 +724,8 @@ kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data) case PT_SYSCALL: case PT_FOLLOW_FORK: case PT_LWP_EVENTS: + case PT_GET_EVENT_MASK: + case PT_SET_EVENT_MASK: case PT_DETACH: sx_xlock(&proctree_lock); proctree_locked = 1; @@ -885,6 +900,7 @@ kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data) case PT_TRACE_ME: /* set my trace flag and "owner" so it can read/write me */ p->p_flag |= P_TRACED; + p->p_ptevents = PTRACE_DEFAULT; if (p->p_flag & P_PPWAIT) p->p_flag |= P_PPTRACE; p->p_oppid = p->p_pptr->p_pid; @@ -903,6 +919,7 @@ kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data) * on a "detach". */ p->p_flag |= P_TRACED; + p->p_ptevents = PTRACE_DEFAULT; p->p_oppid = p->p_pptr->p_pid; if (p->p_pptr != td->td_proc) { proc_reparent(p, td->td_proc); @@ -941,24 +958,50 @@ kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data) case PT_FOLLOW_FORK: CTR3(KTR_PTRACE, "PT_FOLLOW_FORK: pid %d %s -> %s", p->p_pid, - p->p_flag & P_FOLLOWFORK ? "enabled" : "disabled", + p->p_ptevents & PTRACE_FORK ? "enabled" : "disabled", data ? "enabled" : "disabled"); if (data) - p->p_flag |= P_FOLLOWFORK; + p->p_ptevents |= PTRACE_FORK; else - p->p_flag &= ~P_FOLLOWFORK; + p->p_ptevents &= ~PTRACE_FORK; break; case PT_LWP_EVENTS: CTR3(KTR_PTRACE, "PT_LWP_EVENTS: pid %d %s -> %s", p->p_pid, - p->p_flag2 & P2_LWP_EVENTS ? "enabled" : "disabled", + p->p_ptevents & PTRACE_LWP ? "enabled" : "disabled", data ? "enabled" : "disabled"); if (data) - p->p_flag2 |= P2_LWP_EVENTS; + p->p_ptevents |= PTRACE_LWP; else - p->p_flag2 &= ~P2_LWP_EVENTS; + p->p_ptevents &= ~PTRACE_LWP; + break; + + case PT_GET_EVENT_MASK: + if (data != sizeof(p->p_ptevents)) { + error = EINVAL; + break; + } + CTR2(KTR_PTRACE, "PT_GET_EVENT_MASK: pid %d mask %#x", p->p_pid, + p->p_ptevents); + *(int *)addr = p->p_ptevents; break; + case PT_SET_EVENT_MASK: + if (data != sizeof(p->p_ptevents)) { + error = EINVAL; + break; + } + tmp = *(int *)addr; + if ((tmp & ~(PTRACE_EXEC | PTRACE_SCE | PTRACE_SCX | + PTRACE_FORK | PTRACE_LWP)) != 0) { + error = EINVAL; + break; + } + CTR3(KTR_PTRACE, "PT_SET_EVENT_MASK: pid %d mask %#x -> %#x", + p->p_pid, p->p_ptevents, tmp); + p->p_ptevents = tmp; + break; + case PT_STEP: case PT_CONTINUE: case PT_TO_SCE: @@ -991,24 +1034,24 @@ kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data) } switch (req) { case PT_TO_SCE: - p->p_stops |= S_PT_SCE; + p->p_ptevents |= PTRACE_SCE; CTR4(KTR_PTRACE, - "PT_TO_SCE: pid %d, stops = %#x, PC = %#lx, sig = %d", - p->p_pid, p->p_stops, + "PT_TO_SCE: pid %d, events = %#x, PC = %#lx, sig = %d", + p->p_pid, p->p_ptevents, (u_long)(uintfptr_t)addr, data); break; case PT_TO_SCX: - p->p_stops |= S_PT_SCX; + p->p_ptevents |= PTRACE_SCX; CTR4(KTR_PTRACE, - "PT_TO_SCX: pid %d, stops = %#x, PC = %#lx, sig = %d", - p->p_pid, p->p_stops, + "PT_TO_SCX: pid %d, events = %#x, PC = %#lx, sig = %d", + p->p_pid, p->p_ptevents, (u_long)(uintfptr_t)addr, data); break; case PT_SYSCALL: - p->p_stops |= S_PT_SCE | S_PT_SCX; + p->p_ptevents |= PTRACE_SYSCALL; CTR4(KTR_PTRACE, - "PT_SYSCALL: pid %d, stops = %#x, PC = %#lx, sig = %d", - p->p_pid, p->p_stops, + "PT_SYSCALL: pid %d, events = %#x, PC = %#lx, sig = %d", + p->p_pid, p->p_ptevents, (u_long)(uintfptr_t)addr, data); break; case PT_CONTINUE: @@ -1027,7 +1070,7 @@ kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data) * parent. Otherwise the debugee will be set * as an orphan of the debugger. */ - p->p_flag &= ~(P_TRACED | P_WAITED | P_FOLLOWFORK); + p->p_flag &= ~(P_TRACED | P_WAITED); if (p->p_oppid != p->p_pptr->p_pid) { PROC_LOCK(p->p_pptr); sigqueue_take(p->p_ksi); @@ -1044,7 +1087,7 @@ kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data) CTR2(KTR_PTRACE, "PT_DETACH: pid %d, sig %d", p->p_pid, data); p->p_oppid = 0; - p->p_stops = 0; + p->p_ptevents = 0; /* should we send SIGCHLD? */ /* childproc_continued(p); */ -- cgit v1.1