[DTrace-devel] [PATCH] Show signed values for signed immediate conditional branches

[Kris Van Hees]

The disassembler will not print negative values correctly in signed
conditional branch instructions with an immediate operand.

Signed-off-by: Kris Van Hees <kris.van.hees at oracle.com>
---
 libdtrace/dt_dis.c | 33 +++++++++++++++++++++------------
 1 file changed, 21 insertions(+), 12 deletions(-)

diff --git a/libdtrace/dt_dis.c b/libdtrace/dt_dis.c
index 4a700ac6..8ec72f3c 100644
--- a/libdtrace/dt_dis.c
+++ b/libdtrace/dt_dis.c
@@ -187,10 +187,7 @@ dt_dis_refname(const dtrace_difo_t *dp, const struct bpf_insn *in, uint_t addr,
 			[DMST_PRID]			= "prid",
 			[DMST_CLID]			= "clid",
 			[DMST_TAG]			= "tag",
-			[DMST_SCRATCH_TOP]		= "scratch_top",
-			[DMST_SCRATCH_NEXT]		= "scratch_next",
 			[DMST_ERRNO]			= "syscall_errno",
-			[DMST_SCALARIZER]		= "scalarizer",
 			[DMST_FAULT]			= "fault",
 			[DMST_TSTAMP]			= "tstamp",
 			[DMST_REGS]			= "regs",
@@ -289,6 +286,19 @@ dt_dis_branch_imm(const dtrace_difo_t *dp, const char *name, uint_t addr,
 	return 0;
 }
 
+/*ARGSUSED*/
+static uint_t
+dt_dis_sbranch_imm(const dtrace_difo_t *dp, const char *name, uint_t addr,
+	      const struct bpf_insn *in, const char *rname, FILE *fp)
+{
+	int	n;
+
+	n = fprintf(fp, "%-4s %s, %d, %d", name, reg(in->dst_reg), in->imm,
+		    in->off);
+	fprintf(fp, "%*s! -> %03u\n", DT_DIS_PAD(n), "", addr + 1 + in->off);
+	return 0;
+}
+
 /*ARGSUSED*/
 static uint_t
 dt_dis_load(const dtrace_difo_t *dp, const char *name, uint_t addr,
@@ -320,7 +330,6 @@ dt_dis_load(const dtrace_difo_t *dp, const char *name, uint_t addr,
 				[DCTX_MST]		= "mst",
 				[DCTX_BUF]		= "buf",
 				[DCTX_MEM]		= "mem",
-				[DCTX_SCRATCHMEM]	= "scratchmem",
 				[DCTX_STRTAB]		= "strtab",
 				[DCTX_AGG]		= "agg",
 				[DCTX_GVARS]		= "gvars",
@@ -724,10 +733,10 @@ dt_dis_difo(const dtrace_difo_t *dp, FILE *fp, const dt_ident_t *idp,
 		INSN3(JMP32, JLT, K)	= { "jlt", dt_dis_branch_imm },
 		INSN3(JMP32, JGE, K)	= { "jge", dt_dis_branch_imm },
 		INSN3(JMP32, JLE, K)	= { "jle", dt_dis_branch_imm },
-		INSN3(JMP32, JSGT, K)	= { "jsgt", dt_dis_branch_imm },
-		INSN3(JMP32, JSLT, K)	= { "jslt", dt_dis_branch_imm },
-		INSN3(JMP32, JSGE, K)	= { "jsge", dt_dis_branch_imm },
-		INSN3(JMP32, JSLE, K)	= { "jsle", dt_dis_branch_imm },
+		INSN3(JMP32, JSGT, K)	= { "jsgt", dt_dis_sbranch_imm },
+		INSN3(JMP32, JSLT, K)	= { "jslt", dt_dis_sbranch_imm },
+		INSN3(JMP32, JSGE, K)	= { "jsge", dt_dis_sbranch_imm },
+		INSN3(JMP32, JSLE, K)	= { "jsle", dt_dis_sbranch_imm },
 		INSN3(JMP32, JSET, K)	= { "jset", dt_dis_branch_imm },
 		/* 64-bit jump ops, op(dst, src) */
 		INSN3(JMP, JEQ, X)	= { "jeq", dt_dis_branch },
@@ -748,10 +757,10 @@ dt_dis_difo(const dtrace_difo_t *dp, FILE *fp, const dt_ident_t *idp,
 		INSN3(JMP, JLT, K)	= { "jlt", dt_dis_branch_imm },
 		INSN3(JMP, JGE, K)	= { "jge", dt_dis_branch_imm },
 		INSN3(JMP, JLE, K)	= { "jle", dt_dis_branch_imm },
-		INSN3(JMP, JSGT, K)	= { "jsgt", dt_dis_branch_imm },
-		INSN3(JMP, JSLT, K)	= { "jslt", dt_dis_branch_imm },
-		INSN3(JMP, JSGE, K)	= { "jsge", dt_dis_branch_imm },
-		INSN3(JMP, JSLE, K)	= { "jsle", dt_dis_branch_imm },
+		INSN3(JMP, JSGT, K)	= { "jsgt", dt_dis_sbranch_imm },
+		INSN3(JMP, JSLT, K)	= { "jslt", dt_dis_sbranch_imm },
+		INSN3(JMP, JSGE, K)	= { "jsge", dt_dis_sbranch_imm },
+		INSN3(JMP, JSLE, K)	= { "jsle", dt_dis_sbranch_imm },
 		INSN3(JMP, JSET, K)	= { "jset", dt_dis_branch_imm },
 		INSN2(JMP, JA)		= { "ja", dt_dis_jump },
 		/* Store instructions, [dst + off] = src */
-- 
2.34.1