Commit d4e13c21 authored by Alexandre Chartre's avatar Alexandre Chartre Committed by Peter Zijlstra
Browse files

objtool: Store instruction disassembly result 



When disassembling an instruction store the result instead of directly
printing it.

Signed-off-by: default avatarAlexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarJosh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-7-alexandre.chartre@oracle.com
parent 5d859dff

tools/objtool/disas.c

+71 −6
Original line number Diff line number Diff line
@@ -12,9 +12,16 @@ 
#include <linux/string.h>

#include <tools/dis-asm-compat.h>



/*

 * Size of the buffer for storing the result of disassembling

 * a single instruction.

 */

#define DISAS_RESULT_SIZE	1024



struct disas_context {

	struct objtool_file *file;

	struct instruction *insn;

	char result[DISAS_RESULT_SIZE];

	disassembler_ftype disassembler;

	struct disassemble_info info;

};
@@ -34,6 +41,59 @@ static int sprint_name(char *str, const char *name, unsigned long offset) 
#define DINFO_FPRINTF(dinfo, ...)	\

	((*(dinfo)->fprintf_func)((dinfo)->stream, __VA_ARGS__))



static int disas_result_fprintf(struct disas_context *dctx,

				const char *fmt, va_list ap)

{

	char *buf = dctx->result;

	int avail, len;



	len = strlen(buf);

	if (len >= DISAS_RESULT_SIZE - 1) {

		WARN_FUNC(dctx->insn->sec, dctx->insn->offset,

			  "disassembly buffer is full");

		return -1;

	}

	avail = DISAS_RESULT_SIZE - len;



	len = vsnprintf(buf + len, avail, fmt, ap);

	if (len < 0 || len >= avail) {

		WARN_FUNC(dctx->insn->sec, dctx->insn->offset,

			  "disassembly buffer is truncated");

		return -1;

	}



	return 0;

}



static int disas_fprintf(void *stream, const char *fmt, ...)

{

	va_list arg;

	int rv;



	va_start(arg, fmt);

	rv = disas_result_fprintf(stream, fmt, arg);

	va_end(arg);



	return rv;

}



/*

 * For init_disassemble_info_compat().

 */

static int disas_fprintf_styled(void *stream,

				enum disassembler_style style,

				const char *fmt, ...)

{

	va_list arg;

	int rv;



	va_start(arg, fmt);

	rv = disas_result_fprintf(stream, fmt, arg);

	va_end(arg);



	return rv;

}



static void disas_print_addr_sym(struct section *sec, struct symbol *sym,

				 bfd_vma addr, struct disassemble_info *dinfo)

{
@@ -195,9 +255,8 @@ struct disas_context *disas_context_create(struct objtool_file *file) 
	dctx->file = file;

	dinfo = &dctx->info;



	init_disassemble_info_compat(dinfo, stdout,

				     (fprintf_ftype)fprintf,

				     fprintf_styled);

	init_disassemble_info_compat(dinfo, dctx,

				     disas_fprintf, disas_fprintf_styled);



	dinfo->read_memory_func = buffer_read_memory;

	dinfo->print_address_func = disas_print_address;
@@ -244,6 +303,11 @@ void disas_context_destroy(struct disas_context *dctx) 
	free(dctx);

}



static char *disas_result(struct disas_context *dctx)

{

	return dctx->result;

}



/*

 * Disassemble a single instruction. Return the size of the instruction.

 */
@@ -254,6 +318,7 @@ static size_t disas_insn(struct disas_context *dctx, 
	struct disassemble_info *dinfo = &dctx->info;



	dctx->insn = insn;

	dctx->result[0] = '\0';



	if (insn->type == INSN_NOP) {

		DINFO_FPRINTF(dinfo, "nop%d", insn->len);
@@ -282,10 +347,10 @@ static void disas_func(struct disas_context *dctx, struct symbol *func) 
	printf("%s:\n", func->name);

	sym_for_each_insn(dctx->file, func, insn) {

		addr = insn->offset;

		printf(" %6lx:  %s+0x%-6lx      ",

		       addr, func->name, addr - func->offset);

		disas_insn(dctx, insn);

		printf("\n");

		printf(" %6lx:  %s+0x%-6lx      %s\n",

		       addr, func->name, addr - func->offset,

		       disas_result(dctx));

	}

	printf("\n");

}