perf unwind: Use perf_arch_reg_{ip|sp}() to substitute macros

We use perf_arch_reg_ip() and perf_arch_reg_sp() to substitute macros
for obtaining the register numbers of SP and IP. This modification
enables cross analysis in the unwinding, therefore, the unwinding is
not restricted to the predefined values by the macros.

Consequently, the macros LIBUNWIND__ARCH_REG_{IP|SP} are removed since
they are no longer used.

Committer notes:

Add missing "util/env.h" header to make sure we have the definition for
perf_env__arch(), that when built with NO_LIBUNWIND=1 isn't available,
i.e. it was being included by sheer luck.

Signed-off-by: Leo Yan <[e-mail]>
Acked-by: Ian Rogers <[e-mail]>
Cc: Adrian Hunter <[e-mail]>
Cc: Albert Ou <[e-mail]>
Cc: Alexander Shishkin <[e-mail]>
Cc: Eric Lin <[e-mail]>
Cc: Fangrui Song <[e-mail]>
Cc: Guo Ren <[e-mail]>
Cc: Huacai Chen <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Ivan Babrou <[e-mail]>
Cc: James Clark <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: John Garry <[e-mail]>
Cc: Kan Liang <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Cc: Mike Leach <[e-mail]>
Cc: Ming Wang <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Palmer Dabbelt <[e-mail]>
Cc: Paul Walmsley <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Sandipan Das <[e-mail]>
Cc: Will Deacon <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/util/libunwind/arm64.c

···
  * defined before including "unwind.h"
  */
 #define LIBUNWIND__ARCH_REG_ID(regnum) libunwind__arm64_reg_id(regnum)
-#define LIBUNWIND__ARCH_REG_IP PERF_REG_ARM64_PC
-#define LIBUNWIND__ARCH_REG_SP PERF_REG_ARM64_SP
 
 #include "unwind.h"
 #include "libunwind-aarch64.h"

tools/perf/util/libunwind/x86_32.c

···
  * defined before including "unwind.h"
  */
 #define LIBUNWIND__ARCH_REG_ID(regnum) libunwind__x86_reg_id(regnum)
-#define LIBUNWIND__ARCH_REG_IP PERF_REG_X86_IP
-#define LIBUNWIND__ARCH_REG_SP PERF_REG_X86_SP
 
 #include "unwind.h"
 #include "libunwind-x86.h"

tools/perf/util/unwind-libdw.c

···
 #include "event.h"
 #include "perf_regs.h"
 #include "callchain.h"
+#include "util/env.h"
 
 static char *debuginfo_path;
 
···
 			void *arg)
 {
 	struct unwind_info *ui = arg;
+	const char *arch = perf_env__arch(ui->machine->env);
 	struct stack_dump *stack = &ui->sample->user_stack;
 	u64 start, end;
 	int offset;
 	int ret;
 
-	ret = perf_reg_value(&start, &ui->sample->user_regs, PERF_REG_SP);
+	ret = perf_reg_value(&start, &ui->sample->user_regs,
+			     perf_arch_reg_sp(arch));
 	if (ret)
 		return false;
 
···
 		.max_stack	= max_stack,
 		.best_effort    = best_effort
 	};
+	const char *arch = perf_env__arch(ui_buf.machine->env);
 	Dwarf_Word ip;
 	int err = -EINVAL, i;
 
···
 	if (!ui->dwfl)
 		goto out;
 
-	err = perf_reg_value(&ip, &data->user_regs, PERF_REG_IP);
+	err = perf_reg_value(&ip, &data->user_regs, perf_arch_reg_ip(arch));
 	if (err)
 		goto out;
 

tools/perf/util/unwind-libunwind-local.c

···
 		      int __write, void *arg)
 {
 	struct unwind_info *ui = arg;
+	const char *arch = perf_env__arch(ui->machine->env);
 	struct stack_dump *stack = &ui->sample->user_stack;
 	u64 start, end;
 	int offset;
···
 	}
 
 	ret = perf_reg_value(&start, &ui->sample->user_regs,
-			     LIBUNWIND__ARCH_REG_SP);
+			     perf_arch_reg_sp(arch));
 	if (ret)
 		return ret;
 
···
 static int get_entries(struct unwind_info *ui, unwind_entry_cb_t cb,
 		       void *arg, int max_stack)
 {
+	const char *arch = perf_env__arch(ui->machine->env);
 	u64 val;
 	unw_word_t ips[max_stack];
 	unw_addr_space_t addr_space;
···
 	int ret, i = 0;
 
 	ret = perf_reg_value(&val, &ui->sample->user_regs,
-			     LIBUNWIND__ARCH_REG_IP);
+			     perf_arch_reg_ip(arch));
 	if (ret)
 		return ret;
 

tools/perf/util/unwind.h

···
 #define LIBUNWIND__ARCH_REG_ID(regnum) libunwind__arch_reg_id(regnum)
 #endif
 
-#ifndef LIBUNWIND__ARCH_REG_SP
-#define LIBUNWIND__ARCH_REG_SP PERF_REG_SP
-#endif
-
-#ifndef LIBUNWIND__ARCH_REG_IP
-#define LIBUNWIND__ARCH_REG_IP PERF_REG_IP
-#endif
-
 int LIBUNWIND__ARCH_REG_ID(int regnum);
 int unwind__prepare_access(struct maps *maps, struct map *map, bool *initialized);
 void unwind__flush_access(struct maps *maps);