git: e3ccf4f9dee9 - main - Fix dtrace fbt return probes on arm64

The branch main has been updated by andrew:

URL: https://cgit.FreeBSD.org/src/commit/?id=e3ccf4f9dee9ae39774639407264199a07fa41ff

commit e3ccf4f9dee9ae39774639407264199a07fa41ff
Author:     Andrew Turner <andrew@FreeBSD.org>
AuthorDate: 2021-12-14 15:49:07 +0000
Commit:     Andrew Turner <andrew@FreeBSD.org>
CommitDate: 2021-12-14 16:32:12 +0000

    Fix dtrace fbt return probes on arm64
    
    As with arm and riscv fix return fbt probes on arm64. arg0 should be
    the offset within the function of the return instruction and arg1
    should be the return value.
    
    Reviewed by:    kp, markj
    Sponsored by:   The FreeBSD Foundation
    Differential Revision: https://reviews.freebsd.org/D33440
---
 sys/cddl/dev/dtrace/aarch64/dtrace_subr.c |  2 +-
 sys/cddl/dev/fbt/aarch64/fbt_isa.c        | 16 +++++++++++-----
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/sys/cddl/dev/dtrace/aarch64/dtrace_subr.c b/sys/cddl/dev/dtrace/aarch64/dtrace_subr.c
index 58d33511560b..74b3bf7ed7d1 100644
--- a/sys/cddl/dev/dtrace/aarch64/dtrace_subr.c
+++ b/sys/cddl/dev/dtrace/aarch64/dtrace_subr.c
@@ -270,7 +270,7 @@ dtrace_invop_start(struct trapframe *frame)
 	int tmp;
 	int i;
 
-	invop = dtrace_invop(frame->tf_elr, frame, frame->tf_elr);
+	invop = dtrace_invop(frame->tf_elr, frame, frame->tf_x[0]);
 
 	tmp = (invop & LDP_STP_MASK);
 	if (tmp == STP_64 || tmp == LDP_64) {
diff --git a/sys/cddl/dev/fbt/aarch64/fbt_isa.c b/sys/cddl/dev/fbt/aarch64/fbt_isa.c
index 4d22f1d584d3..d00aabf0cc81 100644
--- a/sys/cddl/dev/fbt/aarch64/fbt_isa.c
+++ b/sys/cddl/dev/fbt/aarch64/fbt_isa.c
@@ -56,16 +56,21 @@ fbt_invop(uintptr_t addr, struct trapframe *frame, uintptr_t rval)
 	fbt = fbt_probetab[FBT_ADDR2NDX(addr)];
 
 	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) {
 			dtrace_probe(fbt->fbtp_id, frame->tf_x[0],
 			    frame->tf_x[1], frame->tf_x[2],
 			    frame->tf_x[3], frame->tf_x[4]);
-
-			cpu->cpu_dtrace_caller = 0;
-			return (fbt->fbtp_savedval);
+		} else {
+			dtrace_probe(fbt->fbtp_id, fbt->fbtp_roffset, rval,
+			    0, 0, 0);
 		}
+		cpu->cpu_dtrace_caller = 0;
+		return (fbt->fbtp_savedval);
 	}
 
 	return (0);
@@ -216,6 +221,7 @@ again:
 		fbt->fbtp_rval = DTRACE_INVOP_B;
 	else
 		fbt->fbtp_rval = DTRACE_INVOP_RET;
+	fbt->fbtp_roffset = (uintptr_t)instr - (uintptr_t)symval->value;
 	fbt->fbtp_savedval = *instr;
 	fbt->fbtp_patchval = FBT_PATCHVAL;
 	fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)];