Date: Sun, 10 May 2015 22:27:49 +0000 (UTC) From: Mark Johnston <markj@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r282744 - in head/sys/cddl/dev/dtrace: amd64 i386 Message-ID: <201505102227.t4AMRn1g007294@svn.freebsd.org>
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Author: markj Date: Sun May 10 22:27:48 2015 New Revision: 282744 URL: https://svnweb.freebsd.org/changeset/base/282744 Log: Remove some commented-out upstream code for handling traps from usermode DTrace probes. This handling is already done in trap() on i386 and amd64. Modified: head/sys/cddl/dev/dtrace/amd64/dtrace_subr.c head/sys/cddl/dev/dtrace/i386/dtrace_subr.c Modified: head/sys/cddl/dev/dtrace/amd64/dtrace_subr.c ============================================================================== --- head/sys/cddl/dev/dtrace/amd64/dtrace_subr.c Sun May 10 22:21:00 2015 (r282743) +++ head/sys/cddl/dev/dtrace/amd64/dtrace_subr.c Sun May 10 22:27:48 2015 (r282744) @@ -142,114 +142,6 @@ dtrace_sync(void) } #ifdef notyet -int (*dtrace_pid_probe_ptr)(struct regs *); -int (*dtrace_return_probe_ptr)(struct regs *); - -void -dtrace_user_probe(struct regs *rp, caddr_t addr, processorid_t cpuid) -{ - krwlock_t *rwp; - proc_t *p = curproc; - extern void trap(struct regs *, caddr_t, processorid_t); - - if (USERMODE(rp->r_cs) || (rp->r_ps & PS_VM)) { - if (curthread->t_cred != p->p_cred) { - cred_t *oldcred = curthread->t_cred; - /* - * DTrace accesses t_cred in probe context. t_cred - * must always be either NULL, or point to a valid, - * allocated cred structure. - */ - curthread->t_cred = crgetcred(); - crfree(oldcred); - } - } - - if (rp->r_trapno == T_DTRACE_RET) { - uint8_t step = curthread->t_dtrace_step; - uint8_t ret = curthread->t_dtrace_ret; - uintptr_t npc = curthread->t_dtrace_npc; - - if (curthread->t_dtrace_ast) { - aston(curthread); - curthread->t_sig_check = 1; - } - - /* - * Clear all user tracing flags. - */ - curthread->t_dtrace_ft = 0; - - /* - * If we weren't expecting to take a return probe trap, kill - * the process as though it had just executed an unassigned - * trap instruction. - */ - if (step == 0) { - tsignal(curthread, SIGILL); - return; - } - - /* - * If we hit this trap unrelated to a return probe, we're - * just here to reset the AST flag since we deferred a signal - * until after we logically single-stepped the instruction we - * copied out. - */ - if (ret == 0) { - rp->r_pc = npc; - return; - } - - /* - * We need to wait until after we've called the - * dtrace_return_probe_ptr function pointer to set %pc. - */ - rwp = &CPU->cpu_ft_lock; - rw_enter(rwp, RW_READER); - if (dtrace_return_probe_ptr != NULL) - (void) (*dtrace_return_probe_ptr)(rp); - rw_exit(rwp); - rp->r_pc = npc; - - } else if (rp->r_trapno == T_BPTFLT) { - uint8_t instr; - rwp = &CPU->cpu_ft_lock; - - /* - * The DTrace fasttrap provider uses the breakpoint trap - * (int 3). We let DTrace take the first crack at handling - * this trap; if it's not a probe that DTrace knowns about, - * we call into the trap() routine to handle it like a - * breakpoint placed by a conventional debugger. - */ - rw_enter(rwp, RW_READER); - if (dtrace_pid_probe_ptr != NULL && - (*dtrace_pid_probe_ptr)(rp) == 0) { - rw_exit(rwp); - return; - } - rw_exit(rwp); - - /* - * If the instruction that caused the breakpoint trap doesn't - * look like an int 3 anymore, it may be that this tracepoint - * was removed just after the user thread executed it. In - * that case, return to user land to retry the instuction. - */ - if (fuword8((void *)(rp->r_pc - 1), &instr) == 0 && - instr != FASTTRAP_INSTR) { - rp->r_pc--; - return; - } - - trap(rp, addr, cpuid); - - } else { - trap(rp, addr, cpuid); - } -} - void dtrace_safe_synchronous_signal(void) { Modified: head/sys/cddl/dev/dtrace/i386/dtrace_subr.c ============================================================================== --- head/sys/cddl/dev/dtrace/i386/dtrace_subr.c Sun May 10 22:21:00 2015 (r282743) +++ head/sys/cddl/dev/dtrace/i386/dtrace_subr.c Sun May 10 22:27:48 2015 (r282744) @@ -143,122 +143,6 @@ dtrace_sync(void) } #ifdef notyet -int (*dtrace_fasttrap_probe_ptr)(struct regs *); -int (*dtrace_pid_probe_ptr)(struct regs *); -int (*dtrace_return_probe_ptr)(struct regs *); - -void -dtrace_user_probe(struct regs *rp, caddr_t addr, processorid_t cpuid) -{ - krwlock_t *rwp; - proc_t *p = curproc; - extern void trap(struct regs *, caddr_t, processorid_t); - - if (USERMODE(rp->r_cs) || (rp->r_ps & PS_VM)) { - if (curthread->t_cred != p->p_cred) { - cred_t *oldcred = curthread->t_cred; - /* - * DTrace accesses t_cred in probe context. t_cred - * must always be either NULL, or point to a valid, - * allocated cred structure. - */ - curthread->t_cred = crgetcred(); - crfree(oldcred); - } - } - - if (rp->r_trapno == T_DTRACE_RET) { - uint8_t step = curthread->t_dtrace_step; - uint8_t ret = curthread->t_dtrace_ret; - uintptr_t npc = curthread->t_dtrace_npc; - - if (curthread->t_dtrace_ast) { - aston(curthread); - curthread->t_sig_check = 1; - } - - /* - * Clear all user tracing flags. - */ - curthread->t_dtrace_ft = 0; - - /* - * If we weren't expecting to take a return probe trap, kill - * the process as though it had just executed an unassigned - * trap instruction. - */ - if (step == 0) { - tsignal(curthread, SIGILL); - return; - } - - /* - * If we hit this trap unrelated to a return probe, we're - * just here to reset the AST flag since we deferred a signal - * until after we logically single-stepped the instruction we - * copied out. - */ - if (ret == 0) { - rp->r_pc = npc; - return; - } - - /* - * We need to wait until after we've called the - * dtrace_return_probe_ptr function pointer to set %pc. - */ - rwp = &CPU->cpu_ft_lock; - rw_enter(rwp, RW_READER); - if (dtrace_return_probe_ptr != NULL) - (void) (*dtrace_return_probe_ptr)(rp); - rw_exit(rwp); - rp->r_pc = npc; - - } else if (rp->r_trapno == T_DTRACE_PROBE) { - rwp = &CPU->cpu_ft_lock; - rw_enter(rwp, RW_READER); - if (dtrace_fasttrap_probe_ptr != NULL) - (void) (*dtrace_fasttrap_probe_ptr)(rp); - rw_exit(rwp); - - } else if (rp->r_trapno == T_BPTFLT) { - uint8_t instr; - rwp = &CPU->cpu_ft_lock; - - /* - * The DTrace fasttrap provider uses the breakpoint trap - * (int 3). We let DTrace take the first crack at handling - * this trap; if it's not a probe that DTrace knowns about, - * we call into the trap() routine to handle it like a - * breakpoint placed by a conventional debugger. - */ - rw_enter(rwp, RW_READER); - if (dtrace_pid_probe_ptr != NULL && - (*dtrace_pid_probe_ptr)(rp) == 0) { - rw_exit(rwp); - return; - } - rw_exit(rwp); - - /* - * If the instruction that caused the breakpoint trap doesn't - * look like an int 3 anymore, it may be that this tracepoint - * was removed just after the user thread executed it. In - * that case, return to user land to retry the instuction. - */ - if (fuword8((void *)(rp->r_pc - 1), &instr) == 0 && - instr != FASTTRAP_INSTR) { - rp->r_pc--; - return; - } - - trap(rp, addr, cpuid); - - } else { - trap(rp, addr, cpuid); - } -} - void dtrace_safe_synchronous_signal(void) {
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