Replace remaining hard-coded TASK_SIZE use

If we want one CRIU binary to work across all AArch64 kernel
configurations, a single task size value cannot be hard coded. While
trivial applications successfully checkpoint and restore on AArch64
kernels with CONFIG_ARM64_64K_PAGES=y without this patch, replacing
the remaining use of the hard-coded value seems like the best way to
guard against failures that more complex process trees and future uses
may expose.
Signed-off-by: Christopher Covington <cov@codeaurora.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

arch/aarch64/include/asm/types.h

@@ -61,15 +61,12 @@ typedef struct user_pt_regs user_regs_struct_t;
 #define REG_IP(regs)		((u64)(regs).pc)
 #define REG_SYSCALL_NR(regs)	((u64)(regs).regs[8])
 
-// Copied from the Linux kernel arch/arm64/include/asm/memory.h
-// FIXME: what about a 32bit task?
-
-#define TASK_SIZE (1ULL << 39)
-
 /*
  * Range for task size calculated from the following Linux kernel files:
  *   arch/arm64/include/asm/memory.h
  *   arch/arm64/Kconfig
+ *
+ * TODO: handle 32 bit tasks
  */
 #define TASK_SIZE_MIN (1UL << 39)
 #define TASK_SIZE_MAX (1UL << 48)

arch/aarch64/vdso.c

@@ -87,7 +87,7 @@ int parasite_fixup_vdso(struct parasite_ctl *ctl, pid_t pid,
 			continue;
 		}
 
-		if (vma->e->start > TASK_SIZE)
+		if (vma->e->start > kdat.task_size)
 			continue;
 
 		if (vma->e->flags & MAP_GROWSDOWN)

arch/arm/crtools.c

@@ -18,6 +18,7 @@
 #include "parasite-syscall.h"
 #include "restorer.h"
 #include "errno.h"
+#include "kerndat.h"
 
 
 /*
@@ -212,7 +213,7 @@ void *mmap_seized(struct parasite_ctl *ctl,
 
 	err = syscall_seized(ctl, __NR_mmap2, &map,
 			(unsigned long)addr, length, prot, flags, fd, offset >> 12);
-	if (err < 0 || map > TASK_SIZE)
+	if (err < 0 || map > kdat.task_size)
 		map = 0;
 
 	return (void *)map;

cr-restore.c

@@ -2009,7 +2009,7 @@ static long restorer_get_vma_hint(struct list_head *tgt_vma_list,
 	VmaEntry end_e;
 
 	end_vma.e = &end_e;
-	end_e.start = end_e.end = TASK_SIZE;
+	end_e.start = end_e.end = kdat.task_size;
 	prev_vma_end = PAGE_SIZE * 0x10; /* CONFIG_LSM_MMAP_MIN_ADDR=65536 */
 
 	s_vma = list_first_entry(self_vma_list, struct vma_area, list);

pagemap-cache.c

@@ -7,6 +7,7 @@
 #include "util.h"
 #include "log.h"
 #include "vma.h"
+#include "kerndat.h"
 
 #undef	LOG_PREFIX
 #define LOG_PREFIX "pagemap-cache: "
@@ -66,8 +67,8 @@ static int pmc_fill_cache(pmc_t *pmc, struct vma_area *vma)
 	size_t len = vma_area_len(vma);
 	size_t size_map;
 
-	if (high > TASK_SIZE)
-		high = TASK_SIZE;
+	if (high > kdat.task_size)
+		high = kdat.task_size;
 
 	pmc->start = vma->e->start;
 	pmc->end = vma->e->end;

parasite-syscall.c

@@ -56,7 +56,7 @@ static struct vma_area *get_vma_by_ip(struct list_head *vma_area_list, unsigned
 	struct vma_area *vma_area;
 
 	list_for_each_entry(vma_area, vma_area_list, list) {
-		if (vma_area->e->start >= TASK_SIZE)
+		if (vma_area->e->start >= kdat.task_size)
 			continue;
 		if (!(vma_area->e->prot & PROT_EXEC))
 			continue;