arch: Turn save_task_regs into pointer

The get_task_regs() call now accepts a pointer on a function that
is to keep obtained registers somwehere.

In CRIU case this "somewhere" is CoreEntry, for generic compel
user we'll need to add simple memcpy()-s to the library itself.
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

criu/arch/aarch64/crtools.c

@@ -8,6 +8,7 @@
 #include "common/compiler.h"
 #include "ptrace.h"
 #include "asm/processor-flags.h"
+#include "asm/dump.h"
 #include "protobuf.h"
 #include "images/core.pb-c.h"
 #include "images/creds.pb-c.h"
@@ -77,12 +78,9 @@ int syscall_seized(struct parasite_ctl *ctl, int nr, unsigned long *ret,
 	return err;
 }
 
-static int save_task_regs(CoreEntry *core,
-		user_regs_struct_t *regs, user_fpregs_struct_t *fpsimd);
-
 #define assign_reg(dst, src, e)		dst->e = (__typeof__(dst->e))(src)->e
 
-int get_task_regs(pid_t pid, user_regs_struct_t regs, CoreEntry *core)
+int get_task_regs(pid_t pid, user_regs_struct_t regs, save_regs_t save, void *arg)
 {
 	struct iovec iov;
 	user_fpregs_struct_t fpsimd;
@@ -104,15 +102,15 @@ int get_task_regs(pid_t pid, user_regs_struct_t regs, CoreEntry *core)
 		goto err;
 	}
 
-	ret = save_task_regs(core, &regs, &fpsimd);
+	ret = save(arg, &regs, &fpsimd);
 err:
 	return ret;
 }
 
-static int save_task_regs(CoreEntry *core,
-		user_regs_struct_t *regs, user_fpregs_struct_t *fpsimd)
+int save_task_regs(void *x, user_regs_struct_t *regs, user_fpregs_struct_t *fpsimd)
 {
 	int i;
+	CoreEntry *core = x;
 
 	// Save the Aarch64 CPU state
 	for (i = 0; i < 31; ++i)

criu/arch/aarch64/include/asm/dump.h

 #ifndef __CR_ASM_DUMP_H__
 #define __CR_ASM_DUMP_H__
 
-extern int get_task_regs(pid_t pid, user_regs_struct_t regs, CoreEntry *core);
+typedef int (*save_regs_t)(void *, user_regs_struct_t *, user_fpregs_struct_t *);
+extern int save_task_regs(void *, user_regs_struct_t *, user_fpregs_struct_t *);
+extern int get_task_regs(pid_t pid, user_regs_struct_t regs, save_regs_t, void *);
 extern int arch_alloc_thread_info(CoreEntry *core);
 extern void arch_free_thread_info(CoreEntry *core);
 

criu/arch/arm/crtools.c

@@ -4,6 +4,7 @@
 #include "types.h"
 #include "asm/restorer.h"
 #include "common/compiler.h"
+#include "asm/dump.h"
 #include "ptrace.h"
 #include "asm/processor-flags.h"
 #include "protobuf.h"
@@ -79,13 +80,10 @@ int syscall_seized(struct parasite_ctl *ctl, int nr, unsigned long *ret,
 	return err;
 }
 
-static int save_task_regs(CoreEntry *core,
-		user_regs_struct_t *regs, user_fpregs_struct_t *fpregs);
-
 #define assign_reg(dst, src, e)		dst->e = (__typeof__(dst->e))((src)->ARM_##e)
 
 #define PTRACE_GETVFPREGS 27
-int get_task_regs(pid_t pid, user_regs_struct_t regs, CoreEntry *core)
+int get_task_regs(pid_t pid, user_regs_struct_t regs, save_regs_t save, void *arg)
 {
 	user_fpregs_struct_t vfp;
 	int ret = -1;
@@ -114,14 +112,15 @@ int get_task_regs(pid_t pid, user_regs_struct_t regs, CoreEntry *core)
 		}
 	}
 
-	ret = save_task_regs(core, &regs, &vfp);
+	ret = save(arg, &regs, &vfp);
 err:
 	return ret;
 }
 
-static int save_task_regs(CoreEntry *core,
-		user_regs_struct_t *regs, user_fpregs_struct_t *fpregs)
+int save_task_regs(void *x, user_regs_struct_t *regs, user_fpregs_struct_t *fpregs)
 {
+	CoreEntry *core = x;
+
 	// Save the ARM CPU state
 
 	assign_reg(core->ti_arm->gpregs, regs, r0);

criu/arch/arm/include/asm/dump.h

 #ifndef __CR_ASM_DUMP_H__
 #define __CR_ASM_DUMP_H__
 
-extern int get_task_regs(pid_t pid, user_regs_struct_t regs, CoreEntry *core);
+typedef int (*save_regs_t)(void *, user_regs_struct_t *, user_fpregs_struct_t *);
+extern int save_task_regs(void *, user_regs_struct_t *, user_fpregs_struct_t *);
+extern int get_task_regs(pid_t pid, user_regs_struct_t regs, save_regs_t, void *);
 extern int arch_alloc_thread_info(CoreEntry *core);
 extern void arch_free_thread_info(CoreEntry *core);
 

criu/arch/ppc64/crtools.c

@@ -8,6 +8,7 @@
 #include "types.h"
 #include "asm/fpu.h"
 #include "asm/restorer.h"
+#include "asm/dump.h"
 
 #include "cr_options.h"
 #include "common/compiler.h"
@@ -692,9 +693,13 @@ static int __copy_task_regs(user_regs_struct_t *regs,
 	return 0;
 }
 
+int save_task_regs(void *arg, user_regs_struct_t *u, user_fpregs_struct_t *f)
+{
+	return __copy_task_regs(u, f, (CoreEntry *)arg);
+}
 
 /****************************************************************************/
-int get_task_regs(pid_t pid, user_regs_struct_t regs, CoreEntry *core)
+int get_task_regs(pid_t pid, user_regs_struct_t regs, save_regs_t save, void *arg)
 {
 	user_fpregs_struct_t fpregs;
 	int ret;
@@ -703,7 +708,7 @@ int get_task_regs(pid_t pid, user_regs_struct_t regs, CoreEntry *core)
 	if (ret)
 		return ret;
 
-	return __copy_task_regs(&regs, &fpregs, core);
+	return save(arg, &regs, &fpregs);
 }
 
 int arch_alloc_thread_info(CoreEntry *core)

criu/arch/ppc64/include/asm/dump.h

 #ifndef __CR_ASM_DUMP_H__
 #define __CR_ASM_DUMP_H__
 
-extern int get_task_regs(pid_t pid, user_regs_struct_t regs, CoreEntry *core);
+typedef int (*save_regs_t)(void *, user_regs_struct_t *, user_fpregs_struct_t *);
+extern int save_task_regs(void *, user_regs_struct_t *, user_fpregs_struct_t *);
+extern int get_task_regs(pid_t pid, user_regs_struct_t regs, save_regs_t, void *);
 extern int arch_alloc_thread_info(CoreEntry *core);
 extern void arch_free_thread_info(CoreEntry *core);
 

criu/arch/x86/crtools.c

@@ -11,6 +11,7 @@
 #include "asm/parasite-syscall.h"
 #include "asm/restorer.h"
 #include "asm/fpu.h"
+#include "asm/dump.h"
 
 #include "cr_options.h"
 #include "common/compiler.h"
@@ -184,13 +185,11 @@ int syscall_seized(struct parasite_ctl *ctl, int nr, unsigned long *ret,
 	return err;
 }
 
-static int save_task_regs(CoreEntry *core,
-		user_regs_struct_t *regs, user_fpregs_struct_t *fpregs);
-
 #define get_signed_user_reg(pregs, name)				\
 	((user_regs_native(pregs)) ? (int64_t)((pregs)->native.name) :	\
 				(int32_t)((pregs)->compat.name))
-int get_task_regs(pid_t pid, user_regs_struct_t regs, CoreEntry *core)
+
+int get_task_regs(pid_t pid, user_regs_struct_t regs, save_regs_t save, void *arg)
 {
 	user_fpregs_struct_t xsave	= {  }, *xs = NULL;
 
@@ -248,14 +247,14 @@ int get_task_regs(pid_t pid, user_regs_struct_t regs, CoreEntry *core)
 
 	xs = &xsave;
 out:
-	ret = save_task_regs(core, &regs, xs);
+	ret = save(arg, &regs, xs);
 err:
 	return ret;
 }
 
-static int save_task_regs(CoreEntry *core,
-		user_regs_struct_t *regs, user_fpregs_struct_t *fpregs)
+int save_task_regs(void *x, user_regs_struct_t *regs, user_fpregs_struct_t *fpregs)
 {
+	CoreEntry *core = x;
 	UserX86RegsEntry *gpregs	= core->thread_info->gpregs;
 
 #define assign_reg(dst, src, e)		do { dst->e = (__typeof__(dst->e))src.e; } while (0)

criu/arch/x86/include/asm/dump.h

 #ifndef __CR_ASM_DUMP_H__
 #define __CR_ASM_DUMP_H__
 
-extern int get_task_regs(pid_t pid, user_regs_struct_t regs, CoreEntry *core);
+typedef int (*save_regs_t)(void *, user_regs_struct_t *, user_fpregs_struct_t *);
+extern int save_task_regs(void *, user_regs_struct_t *, user_fpregs_struct_t *);
+extern int get_task_regs(pid_t pid, user_regs_struct_t regs, save_regs_t, void *);
 extern int arch_alloc_thread_info(CoreEntry *core);
 extern void arch_free_thread_info(CoreEntry *core);
 

criu/parasite-syscall.c

@@ -667,7 +667,7 @@ int parasite_dump_thread_seized(struct parasite_ctl *ctl, int id,
 		return -1;
 	}
 
-	ret = get_task_regs(pid, octx.regs, core);
+	ret = get_task_regs(pid, octx.regs, save_task_regs, core);
 	if (ret) {
 		pr_err("Can't obtain regs for thread %d\n", pid);
 		return -1;
@@ -1427,7 +1427,7 @@ static int parasite_start_daemon(struct parasite_ctl *ctl, struct pstree_item *i
 	 * while in daemon it is not such.
 	 */
 
-	if (get_task_regs(pid, ctl->orig.regs, item->core[0])) {
+	if (get_task_regs(pid, ctl->orig.regs, save_task_regs, item->core[0])) {
 		pr_err("Can't obtain regs for thread %d\n", pid);
 		return -1;
 	}