[PATCH bpf] bpf, bpftool: Fix incorrect disasm pc

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From: Leon Hwang <leon.hwang@xxxxxxxxx>

This patch addresses the bpftool issue "Wrong callq address displayed"[0].

The issue stemmed from an incorrect program counter (PC) value used during
disassembly with LLVM or libbfd. To calculate the correct address for
relative calls, the PC argument must reflect the actual address in the
kernel.

[0] https://github.com/libbpf/bpftool/issues/109

Fixes: e1947c750ffe ("bpftool: Refactor disassembler for JIT-ed programs")
Signed-off-by: Leon Hwang <leon.hwang@xxxxxxxxx>
---
 tools/bpf/bpftool/jit_disasm.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/bpf/bpftool/jit_disasm.c b/tools/bpf/bpftool/jit_disasm.c
index 7b8d9ec89ebd3..fe8fabba4b05f 100644
--- a/tools/bpf/bpftool/jit_disasm.c
+++ b/tools/bpf/bpftool/jit_disasm.c
@@ -114,8 +114,7 @@ disassemble_insn(disasm_ctx_t *ctx, unsigned char *image, ssize_t len, int pc)
 	char buf[256];
 	int count;
 
-	count = LLVMDisasmInstruction(*ctx, image + pc, len - pc, pc,
-				      buf, sizeof(buf));
+	count = LLVMDisasmInstruction(*ctx, image, len, pc, buf, sizeof(buf));
 	if (json_output)
 		printf_json(buf);
 	else
@@ -360,7 +359,8 @@ int disasm_print_insn(unsigned char *image, ssize_t len, int opcodes,
 			printf("%4x:" DISASM_SPACER, pc);
 		}
 
-		count = disassemble_insn(&ctx, image, len, pc);
+		count = disassemble_insn(&ctx, image + pc, len - pc,
+					 func_ksym + pc);
 
 		if (json_output) {
 			/* Operand array, was started in fprintf_json. Before
-- 
2.44.0





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