[CRIU] [PATCHv2 12/12] criu/vdso: Purge CONFIG_VDSO

Dmitry Safonov dima at arista.com
Wed May 29 19:15:15 MSK 2019


Vigorously remove the config ifdef.
The config option *never* had any excuse to exist:
- for x86 we were grand
- for ppc64/arm64 patches to support mremap() on vdso were long ago
accepted, but regardless - it's not possible to disable CONFIG_VDSO for
those platforms in kernel
- for s390 - patches were mainstreamed not that long ago, but it's not
possible to disable the kernel config
- for arm32 it's possible to disable the kernel config, but kernel
returns to userspace historically through sigpage, not vdso.
That's the only platform that criu disallows to have CONFIG_VDSO=y in
kernel, but that's just meaningles. A kernel patch for sigpage mremap()
has gone into v4.13: commit 280e87e98c09 ("ARM: 8683/1: ARM32: Support
mremap() for sigpage/vDSO").

So, removing the config was long-lived item on my TODO list that bligted
arm32 users and made changes to vdso more complex by all "needed"
iffdeferry. Get rid of it with fire.

Fixes: #446

Signed-off-by: Dmitry Safonov <dima at arista.com>
---
 Makefile                     |  6 +-----
 Makefile.config              |  4 ----
 criu/Makefile.crtools        |  3 ---
 criu/cr-restore.c            |  6 ------
 criu/include/kerndat.h       |  4 ----
 criu/include/parasite-vdso.h |  9 ---------
 criu/include/restorer.h      |  2 --
 criu/include/vdso.h          | 13 -------------
 criu/mem.c                   |  3 +--
 criu/pie/Makefile            | 15 ++++++---------
 criu/pie/Makefile.library    |  9 +--------
 criu/pie/parasite.c          |  8 --------
 criu/pie/restorer.c          |  8 --------
 criu/proc_parse.c            | 14 --------------
 14 files changed, 9 insertions(+), 95 deletions(-)

diff --git a/Makefile b/Makefile
index 475d4abaffdf..09cf2406a1f0 100644
--- a/Makefile
+++ b/Makefile
@@ -56,19 +56,16 @@ ifeq ($(ARCH),arm)
 endif
 
 ifeq ($(ARCH),aarch64)
-        VDSO		:= y
         DEFINES		:= -DCONFIG_AARCH64
 endif
 
 ifeq ($(ARCH),ppc64)
         LDARCH		:= powerpc:common64
-        VDSO		:= y
         DEFINES		:= -DCONFIG_PPC64 -D__SANE_USERSPACE_TYPES__
 endif
 
 ifeq ($(ARCH),x86)
         LDARCH		:= i386:x86-64
-        VDSO		:= y
         DEFINES		:= -DCONFIG_X86_64
 endif
 
@@ -81,7 +78,6 @@ endif
 ifeq ($(ARCH),s390)
         ARCH		:= s390
         SRCARCH		:= s390
-        VDSO		:= y
         DEFINES		:= -DCONFIG_S390
         CFLAGS_PIE	:= -fno-optimize-sibling-calls
 endif
@@ -90,7 +86,7 @@ CFLAGS_PIE		+= -DCR_NOGLIBC
 export CFLAGS_PIE
 
 LDARCH ?= $(SRCARCH)
-export LDARCH VDSO
+export LDARCH
 export PROTOUFIX DEFINES
 
 #
diff --git a/Makefile.config b/Makefile.config
index a853705b3448..008a82289bdc 100644
--- a/Makefile.config
+++ b/Makefile.config
@@ -57,10 +57,6 @@ $(CONFIG_HEADER): scripts/feature-tests.mak $(CONFIG_FILE)
 	$(Q) echo ''							>> $$@
 $(call map,gen-feature-test,$(FEATURES_LIST))
 	$(Q) cat $(CONFIG_FILE) | sed -n -e '/^[^#]/s/^/#define CONFIG_/p' >> $$@
-ifeq ($$(VDSO),y)
-	$(Q) echo '#define CONFIG_VDSO'				>> $$@
-	$(Q) echo ''							>> $$@
-endif
 	$(Q) echo '#endif /* __CR_CONFIG_H__ */'			>> $$@
 endef
 
diff --git a/criu/Makefile.crtools b/criu/Makefile.crtools
index 23dd6d664f5d..6591621edd62 100644
--- a/criu/Makefile.crtools
+++ b/criu/Makefile.crtools
@@ -86,15 +86,12 @@ obj-y			+= fdstore.o
 obj-y			+= uffd.o
 obj-y			+= config.o
 obj-y			+= servicefd.o
-
-ifeq ($(VDSO),y)
 obj-y			+= pie-util-vdso.o
 obj-y			+= vdso.o
 obj-$(CONFIG_COMPAT)	+= pie-util-vdso-elf32.o
 CFLAGS_pie-util-vdso-elf32.o	+= -DCONFIG_VDSO_32
 obj-$(CONFIG_COMPAT)	+= vdso-compat.o
 CFLAGS_REMOVE_vdso-compat.o	+= $(CFLAGS-ASAN) $(CFLAGS-GCOV)
-endif
 
 PROTOBUF_GEN := scripts/protobuf-gen.sh
 
diff --git a/criu/cr-restore.c b/criu/cr-restore.c
index b6274affba74..ecfee1296a33 100644
--- a/criu/cr-restore.c
+++ b/criu/cr-restore.c
@@ -3231,10 +3231,8 @@ static int sigreturn_restore(pid_t pid, struct task_restore_args *task_args, uns
 	struct thread_restore_args *thread_args;
 	struct restore_mem_zone *mz;
 
-#ifdef CONFIG_VDSO
 	struct vdso_maps vdso_maps_rt;
 	unsigned long vdso_rt_size = 0;
-#endif
 
 	struct vm_area_list self_vmas;
 	struct vm_area_list *vmas = &rsti(current)->vmas;
@@ -3285,7 +3283,6 @@ static int sigreturn_restore(pid_t pid, struct task_restore_args *task_args, uns
 	pr_info("%d threads require %ldK of memory\n",
 			current->nr_threads, KBYTES(task_args->bootstrap_len));
 
-#ifdef CONFIG_VDSO
 	if (core_is_compat(core))
 		vdso_maps_rt = vdso_maps_compat;
 	else
@@ -3297,7 +3294,6 @@ static int sigreturn_restore(pid_t pid, struct task_restore_args *task_args, uns
 	if (vdso_rt_size && vdso_maps_rt.sym.vvar_size)
 		vdso_rt_size += ALIGN(vdso_maps_rt.sym.vvar_size, PAGE_SIZE);
 	task_args->bootstrap_len += vdso_rt_size;
-#endif
 
 	/*
 	 * Restorer is a blob (code + args) that will get mapped in some
@@ -3512,7 +3508,6 @@ static int sigreturn_restore(pid_t pid, struct task_restore_args *task_args, uns
 
 	}
 
-#ifdef CONFIG_VDSO
 	/*
 	 * Restorer needs own copy of vdso parameters. Runtime
 	 * vdso must be kept non intersecting with anything else,
@@ -3524,7 +3519,6 @@ static int sigreturn_restore(pid_t pid, struct task_restore_args *task_args, uns
 	task_args->vdso_maps_rt = vdso_maps_rt;
 	task_args->vdso_rt_size = vdso_rt_size;
 	task_args->can_map_vdso = kdat.can_map_vdso;
-#endif
 
 	new_sp = restorer_stack(task_args->t->mz);
 
diff --git a/criu/include/kerndat.h b/criu/include/kerndat.h
index 2740dd3b1250..75e2130b2e92 100644
--- a/criu/include/kerndat.h
+++ b/criu/include/kerndat.h
@@ -5,9 +5,7 @@
 #include "int.h"
 #include "common/config.h"
 #include "asm/kerndat.h"
-#ifdef CONFIG_VDSO
 #include "util-vdso.h"
-#endif
 
 struct stat;
 
@@ -61,11 +59,9 @@ struct kerndat_s {
 	bool has_thp_disable;
 	bool can_map_vdso;
 	bool vdso_hint_reliable;
-#ifdef CONFIG_VDSO
 	struct vdso_symtable	vdso_sym;
 #ifdef CONFIG_COMPAT
 	struct vdso_symtable	vdso_sym_compat;
-#endif
 #endif
 	bool has_nsid;
 	bool has_link_nsid;
diff --git a/criu/include/parasite-vdso.h b/criu/include/parasite-vdso.h
index 6667fe5c458d..3cf67bbb325e 100644
--- a/criu/include/parasite-vdso.h
+++ b/criu/include/parasite-vdso.h
@@ -2,9 +2,6 @@
 #define __CR_PARASITE_VDSO_H__
 
 #include "common/config.h"
-
-#ifdef CONFIG_VDSO
-
 #include "util-vdso.h"
 #include "images/vma.pb-c.h"
 
@@ -95,10 +92,4 @@ extern int vdso_redirect_calls(unsigned long base_to, unsigned long base_from,
 			struct vdso_symtable *to, struct vdso_symtable *from,
 			bool compat_vdso);
 
-#else /* CONFIG_VDSO */
-#define vdso_do_park(sym_rt, park_at, park_size)		(0)
-#define vdso_map_compat(map_at)					(0)
-
-#endif /* CONFIG_VDSO */
-
 #endif /* __CR_PARASITE_VDSO_H__ */
diff --git a/criu/include/restorer.h b/criu/include/restorer.h
index b83e9130c505..effbc3655efd 100644
--- a/criu/include/restorer.h
+++ b/criu/include/restorer.h
@@ -207,11 +207,9 @@ struct task_restore_args {
 
 	bool				can_map_vdso;
 	bool				auto_dedup;
-#ifdef CONFIG_VDSO
 	unsigned long			vdso_rt_size;
 	struct vdso_maps		vdso_maps_rt;		/* runtime vdso symbols */
 	unsigned long			vdso_rt_parked_at;	/* safe place to keep vdso */
-#endif
 	void				**breakpoint;
 
 	enum faults			fault_strategy;
diff --git a/criu/include/vdso.h b/criu/include/vdso.h
index 1719f3fb7271..fd30772b415c 100644
--- a/criu/include/vdso.h
+++ b/criu/include/vdso.h
@@ -5,9 +5,6 @@
 #include <stdbool.h>
 
 #include "common/config.h"
-
-#ifdef CONFIG_VDSO
-
 #include "util-vdso.h"
 
 extern struct vdso_maps vdso_maps;
@@ -26,14 +23,4 @@ extern void compat_vdso_helper(struct vdso_maps *native, int pipe_fd,
 		int err_fd, void *vdso_buf, size_t buf_size);
 #endif
 
-#else /* CONFIG_VDSO */
-
-#define vdso_init_dump()					(0)
-#define vdso_init_restore()					(0)
-#define kerndat_vdso_fill_symtable()				(0)
-#define kerndat_vdso_preserves_hint()				(0)
-#define parasite_fixup_vdso(ctl, pid, vma_area_list)		(0)
-
-#endif /* CONFIG_VDSO */
-
 #endif /* __CR_VDSO_H__ */
diff --git a/criu/mem.c b/criu/mem.c
index b1d13188b4e3..6a1a87a1e593 100644
--- a/criu/mem.c
+++ b/criu/mem.c
@@ -101,7 +101,6 @@ static inline bool __page_in_parent(bool dirty)
 
 bool should_dump_page(VmaEntry *vmae, u64 pme)
 {
-#ifdef CONFIG_VDSO
 	/*
 	 * vDSO area must be always dumped because on restore
 	 * we might need to generate a proxy.
@@ -117,7 +116,7 @@ bool should_dump_page(VmaEntry *vmae, u64 pme)
 	 */
 	if (vma_entry_is(vmae, VMA_AREA_VVAR))
 		return false;
-#endif
+
 	/*
 	 * Optimisation for private mapping pages, that haven't
 	 * yet being COW-ed
diff --git a/criu/pie/Makefile b/criu/pie/Makefile
index 47443c26b3d8..1ad456f43007 100644
--- a/criu/pie/Makefile
+++ b/criu/pie/Makefile
@@ -16,6 +16,7 @@ endif
 
 LDS		:= compel/arch/$(SRCARCH)/scripts/compel-pack.lds.S
 
+restorer-obj-y	+= parasite-vdso.o ./$(ARCH_DIR)/vdso-pie.o
 restorer-obj-y	+= ./$(ARCH_DIR)/restorer.o
 
 ifeq ($(ARCH),x86)
@@ -25,16 +26,12 @@ ifeq ($(ARCH),x86)
         endif
 endif
 
-ifeq ($(VDSO),y)
-        restorer-obj-y		+= parasite-vdso.o ./$(ARCH_DIR)/vdso-pie.o
-
-        ifeq ($(SRCARCH),aarch64)
-                restorer-obj-y	+= ./$(ARCH_DIR)/intraprocedure.o
-        endif
+ifeq ($(SRCARCH),aarch64)
+        restorer-obj-y	+= ./$(ARCH_DIR)/intraprocedure.o
+endif
 
-        ifeq ($(SRCARCH),ppc64)
-                restorer-obj-y	+= ./$(ARCH_DIR)/vdso-trampoline.o
-        endif
+ifeq ($(SRCARCH),ppc64)
+        restorer-obj-y	+= ./$(ARCH_DIR)/vdso-trampoline.o
 endif
 
 define gen-pie-rules
diff --git a/criu/pie/Makefile.library b/criu/pie/Makefile.library
index d802417de288..658c8a4eb80a 100644
--- a/criu/pie/Makefile.library
+++ b/criu/pie/Makefile.library
@@ -7,14 +7,7 @@
 lib-name		:= pie.lib.a
 
 lib-y			+= util.o
-
-ifeq ($(VDSO),y)
-        lib-y		+= util-vdso.o
-endif
-
-ifeq ($(SRCARCH),ppc64)
-        lib-y		+= ./$(ARCH_DIR)/misc.o
-endif
+lib-y			+= util-vdso.o
 
 ifeq ($(SRCARCH),x86)
         ifeq ($(CONFIG_COMPAT),y)
diff --git a/criu/pie/parasite.c b/criu/pie/parasite.c
index c32e31384fd8..01bacd311bf0 100644
--- a/criu/pie/parasite.c
+++ b/criu/pie/parasite.c
@@ -573,7 +573,6 @@ err_io:
 #undef __tty_ioctl
 }
 
-#ifdef CONFIG_VDSO
 static int parasite_check_vdso_mark(struct parasite_vdso_vma_entry *args)
 {
 	struct vdso_mark *m = (void *)args->start;
@@ -609,13 +608,6 @@ static int parasite_check_vdso_mark(struct parasite_vdso_vma_entry *args)
 
 	return 0;
 }
-#else
-static inline int parasite_check_vdso_mark(struct parasite_vdso_vma_entry *args)
-{
-	pr_err("Unexpected VDSO check command\n");
-	return -1;
-}
-#endif
 
 static int parasite_dump_cgroup(struct parasite_dump_cgroup_args *args)
 {
diff --git a/criu/pie/restorer.c b/criu/pie/restorer.c
index f2db115ffd4b..513be74e0446 100644
--- a/criu/pie/restorer.c
+++ b/criu/pie/restorer.c
@@ -1081,11 +1081,7 @@ static void restore_posix_timers(struct task_restore_args *args)
  * sys_munmap must not return here. The control process must
  * trap us on the exit from sys_munmap.
  */
-#ifdef CONFIG_VDSO
 unsigned long vdso_rt_size = 0;
-#else
-#define vdso_rt_size	(0)
-#endif
 
 void *bootstrap_start = NULL;
 unsigned int bootstrap_len = 0;
@@ -1259,9 +1255,7 @@ long __export_restore_task(struct task_restore_args *args)
 	bootstrap_start = args->bootstrap_start;
 	bootstrap_len	= args->bootstrap_len;
 
-#ifdef CONFIG_VDSO
 	vdso_rt_size	= args->vdso_rt_size;
-#endif
 
 	fi_strategy = args->fault_strategy;
 
@@ -1446,7 +1440,6 @@ long __export_restore_task(struct task_restore_args *args)
 
 	sys_close(args->vma_ios_fd);
 
-#ifdef CONFIG_VDSO
 	/*
 	 * Proxify vDSO.
 	 */
@@ -1454,7 +1447,6 @@ long __export_restore_task(struct task_restore_args *args)
 		     args->vmas, args->vmas_n, args->compatible_mode,
 		     fault_injected(FI_VDSO_TRAMPOLINES)))
 		goto core_restore_end;
-#endif
 
 	/*
 	 * Walk though all VMAs again to drop PROT_WRITE
diff --git a/criu/proc_parse.c b/criu/proc_parse.c
index 3d852d7556c8..f6ebb1fd6f50 100644
--- a/criu/proc_parse.c
+++ b/criu/proc_parse.c
@@ -502,7 +502,6 @@ err:
 	return -1;
 }
 
-#ifdef CONFIG_VDSO
 static inline int handle_vdso_vma(struct vma_area *vma)
 {
 	vma->e->status |= VMA_AREA_REGULAR;
@@ -518,19 +517,6 @@ static inline int handle_vvar_vma(struct vma_area *vma)
 		vma->e->status |= VMA_AREA_VVAR;
 	return 0;
 }
-#else
-static inline int handle_vdso_vma(struct vma_area *vma)
-{
-	pr_warn_once("Found vDSO area without support\n");
-	return -1;
-}
-
-static inline int handle_vvar_vma(struct vma_area *vma)
-{
-	pr_warn_once("Found VVAR area without support\n");
-	return -1;
-}
-#endif
 
 static int handle_vma(pid_t pid, struct vma_area *vma_area,
 			const char *file_path, DIR *map_files_dir,
-- 
2.21.0



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