Author: avg Date: Tue Jul 21 07:41:36 2020 New Revision: 363383 URL: https://svnweb.freebsd.org/changeset/base/363383
Log: dtrace/fbt: fix return probe arguments on arm arg0 should be an offset of the return point within the function, arg1 should be the return value. Previously the return probe had arguments as if for the entry probe. Tested on armv7. andrew noted that the same problem seems to be present on arm64, mips, and riscv. I am not sure if I will get around to fixing those. So, platform users or anyone looking to make a contribution please be aware of this opportunity. Reviewed by: markj MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D25685 Modified: head/sys/cddl/dev/dtrace/arm/dtrace_subr.c head/sys/cddl/dev/fbt/arm/fbt_isa.c Modified: head/sys/cddl/dev/dtrace/arm/dtrace_subr.c ============================================================================== --- head/sys/cddl/dev/dtrace/arm/dtrace_subr.c Tue Jul 21 07:35:03 2020 (r363382) +++ head/sys/cddl/dev/dtrace/arm/dtrace_subr.c Tue Jul 21 07:41:36 2020 (r363383) @@ -248,7 +248,7 @@ dtrace_invop_start(struct trapframe *frame) register_t *r0, *sp; int data, invop, reg, update_sp; - invop = dtrace_invop(frame->tf_pc, frame, frame->tf_pc); + invop = dtrace_invop(frame->tf_pc, frame, frame->tf_r0); switch (invop & DTRACE_INVOP_MASK) { case DTRACE_INVOP_PUSHM: sp = (register_t *)frame->tf_svc_sp; Modified: head/sys/cddl/dev/fbt/arm/fbt_isa.c ============================================================================== --- head/sys/cddl/dev/fbt/arm/fbt_isa.c Tue Jul 21 07:35:03 2020 (r363382) +++ head/sys/cddl/dev/fbt/arm/fbt_isa.c Tue Jul 21 07:41:36 2020 (r363383) @@ -56,9 +56,12 @@ fbt_invop(uintptr_t addr, struct trapframe *frame, uin register_t fifthparam; for (; fbt != NULL; fbt = fbt->fbtp_hashnext) { - if ((uintptr_t)fbt->fbtp_patchpoint == addr) { - cpu->cpu_dtrace_caller = addr; + if ((uintptr_t)fbt->fbtp_patchpoint != addr) + continue; + cpu->cpu_dtrace_caller = addr; + + if (fbt->fbtp_roffset == 0) { /* Get 5th parameter from stack */ DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); fifthparam = *(register_t *)frame->tf_svc_sp; @@ -67,11 +70,13 @@ fbt_invop(uintptr_t addr, struct trapframe *frame, uin dtrace_probe(fbt->fbtp_id, frame->tf_r0, frame->tf_r1, frame->tf_r2, frame->tf_r3, fifthparam); - - cpu->cpu_dtrace_caller = 0; - - return (fbt->fbtp_rval | (fbt->fbtp_savedval << DTRACE_INVOP_SHIFT)); + } else { + dtrace_probe(fbt->fbtp_id, fbt->fbtp_roffset, rval, + 0, 0, 0); } + + cpu->cpu_dtrace_caller = 0; + return (fbt->fbtp_rval | (fbt->fbtp_savedval << DTRACE_INVOP_SHIFT)); } return (0); @@ -178,6 +183,7 @@ again: fbt->fbtp_rval = DTRACE_INVOP_B; else fbt->fbtp_rval = DTRACE_INVOP_POPM; + fbt->fbtp_roffset = (uintptr_t)instr - (uintptr_t)symval->value; fbt->fbtp_savedval = *instr; fbt->fbtp_patchval = FBT_BREAKPOINT; fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)]; _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
