kernel: binder: use kallsyms_lookup_name for internal symbol access

kernel/binder/Makefile

-ccflags-y += -I$(src)
-
-ifneq ($(KERNELRELEASE),)
+ccflags-y += -I$(src) -Wno-int-conversion
 obj-m := binder_linux.o
 binder_linux-y := deps.o binder.o
 
-$(obj)/deps.o: $(src)/deps.h
-
-$(obj)/deps.h: $(src)/gen_deps.sh
-	sudo $(src)/gen_deps.sh > $@
-else
 KERNEL_SRC ?= /lib/modules/$(shell uname -r)/build
 
 all:
@@ -19,4 +12,3 @@ install:
 
 clean:
 	rm -rf deps.h *.o *.ko *.mod.c *.symvers *.order .*.cmd .tmp_versions
-endif

kernel/binder/deps.c

@@ -5,96 +5,125 @@
 #include <linux/mm.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
-
-#include "deps.h"
-
-static struct vm_struct *(*get_vm_area_ptr)(unsigned long, unsigned long) = GET_VM_AREA;
-static void (*zap_page_range_ptr)(struct vm_area_struct *, unsigned long, unsigned long, struct zap_details *) = ZAP_PAGE_RANGE;
-static int (*map_kernel_range_noflush_ptr)(unsigned long start, unsigned long size, pgprot_t prot, struct page **pages) = MAP_KERNEL_RANGE_NOFLUSH;
-static void (*unmap_kernel_range_ptr)(unsigned long, unsigned long) = UNMAP_KERNEL_RANGE;
-static struct files_struct *(*get_files_struct_ptr)(struct task_struct *) = GET_FILES_STRUCT;
-static void (*put_files_struct_ptr)(struct files_struct *) = PUT_FILES_STRUCT;
-static struct sighand_struct *(*__lock_task_sighand_ptr)(struct task_struct *, unsigned long *) = __LOCK_TASK_SIGHAND;
-static int (*__alloc_fd_ptr)(struct files_struct *files, unsigned start, unsigned end, unsigned flags) = __ALLOC_FD;
-static void (*__fd_install_ptr)(struct files_struct *files, unsigned int fd, struct file *file) = __FD_INSTALL;
-static int (*__close_fd_ptr)(struct files_struct *files, unsigned int fd) = __CLOSE_FD;
-static int (*can_nice_ptr)(const struct task_struct *, const int) = CAN_NICE;
-static int (*security_binder_set_context_mgr_ptr)(struct task_struct *mgr) = SECURITY_BINDER_SET_CONTEXT_MGR;
-static int (*security_binder_transaction_ptr)(struct task_struct *from, struct task_struct *to) = SECURITY_BINDER_TRANSACTION;
-static int (*security_binder_transfer_binder_ptr)(struct task_struct *from, struct task_struct *to) = SECURITY_BINDER_TRANSFER_BINDER;
-static int (*security_binder_transfer_file_ptr)(struct task_struct *from, struct task_struct *to, struct file *file) = SECURITY_BINDER_TRANSFER_FILE;
+#include <linux/kallsyms.h>
+
+static struct vm_struct *(*get_vm_area_ptr)(unsigned long, unsigned long) = NULL;
+static void (*zap_page_range_ptr)(struct vm_area_struct *, unsigned long, unsigned long, struct zap_details *) = NULL;
+static int (*map_kernel_range_noflush_ptr)(unsigned long start, unsigned long size, pgprot_t prot, struct page **pages) = NULL;
+static void (*unmap_kernel_range_ptr)(unsigned long, unsigned long) = NULL;
+static struct files_struct *(*get_files_struct_ptr)(struct task_struct *) = NULL;
+static void (*put_files_struct_ptr)(struct files_struct *) = NULL;
+static struct sighand_struct *(*__lock_task_sighand_ptr)(struct task_struct *, unsigned long *) = NULL;
+static int (*__alloc_fd_ptr)(struct files_struct *files, unsigned start, unsigned end, unsigned flags) = NULL;
+static void (*__fd_install_ptr)(struct files_struct *files, unsigned int fd, struct file *file) = NULL;
+static int (*__close_fd_ptr)(struct files_struct *files, unsigned int fd) = NULL;
+static int (*can_nice_ptr)(const struct task_struct *, const int) = NULL;
+static int (*security_binder_set_context_mgr_ptr)(struct task_struct *mgr) = NULL;
+static int (*security_binder_transaction_ptr)(struct task_struct *from, struct task_struct *to) = NULL;
+static int (*security_binder_transfer_binder_ptr)(struct task_struct *from, struct task_struct *to) = NULL;
+static int (*security_binder_transfer_file_ptr)(struct task_struct *from, struct task_struct *to, struct file *file) = NULL;
 
 struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
 {
+	if (!get_vm_area_ptr)
+		get_vm_area_ptr = kallsyms_lookup_name("get_vm_area");
 	return get_vm_area_ptr(size, flags);
 }
 
 void zap_page_range(struct vm_area_struct *vma, unsigned long address, unsigned long size, struct zap_details *details)
 {
+	if (!zap_page_range_ptr)
+		zap_page_range_ptr = kallsyms_lookup_name("zap_page_range");
 	zap_page_range_ptr(vma, address, size, details);
 }
 
 int map_kernel_range_noflush(unsigned long start, unsigned long size, pgprot_t prot, struct page **pages)
 {
+	if (!map_kernel_range_noflush_ptr)
+		map_kernel_range_noflush_ptr = kallsyms_lookup_name("map_kernel_range_noflush");
 	return map_kernel_range_noflush_ptr(start, size, prot, pages);
 }
 
 void unmap_kernel_range(unsigned long addr, unsigned long size)
 {
+	if (!unmap_kernel_range_ptr)
+		unmap_kernel_range_ptr = kallsyms_lookup_name("unmap_kernel_range");
 	unmap_kernel_range_ptr(addr, size);
 }
 
 struct files_struct *get_files_struct(struct task_struct *task)
 {
+	if (!get_files_struct_ptr)
+		get_files_struct_ptr = kallsyms_lookup_name("get_files_struct");
 	return get_files_struct_ptr(task);
 }
 
 void put_files_struct(struct files_struct *files)
 {
+	if (!put_files_struct_ptr)
+		put_files_struct_ptr = kallsyms_lookup_name("put_files_struct");
 	put_files_struct_ptr(files);
 }
 
 struct sighand_struct *__lock_task_sighand(struct task_struct *tsk, unsigned long *flags)
 {
+	if (!__lock_task_sighand_ptr)
+		__lock_task_sighand_ptr = kallsyms_lookup_name("__lock_task_sighand");
 	return __lock_task_sighand_ptr(tsk, flags);
 }
 
 int __alloc_fd(struct files_struct *files, unsigned start, unsigned end, unsigned flags)
 {
+	if (!__alloc_fd_ptr)
+		__alloc_fd_ptr = kallsyms_lookup_name("__alloc_fd");
 	return __alloc_fd_ptr(files, start, end, flags);
 }
 
 void __fd_install(struct files_struct *files, unsigned int fd, struct file *file)
 {
+	if (!__fd_install_ptr)
+		__fd_install_ptr = kallsyms_lookup_name("__fd_install");
 	__fd_install_ptr(files, fd, file);
 }
 
 int __close_fd(struct files_struct *files, unsigned int fd)
 {
+	if (!__close_fd_ptr)
+		__close_fd_ptr = kallsyms_lookup_name("__close_fd_ptr");
 	return __close_fd_ptr(files, fd);
 }
 
 int can_nice(const struct task_struct *p, const int nice)
 {
+	if (!can_nice_ptr)
+		can_nice_ptr = kallsyms_lookup_name("can_nice");
 	return can_nice_ptr(p, nice);
 }
 
 int security_binder_set_context_mgr(struct task_struct *mgr)
 {
+	if (!security_binder_set_context_mgr_ptr)
+		security_binder_set_context_mgr_ptr = kallsyms_lookup_name("security_binder_set_context_mgr");
 	return security_binder_set_context_mgr_ptr(mgr);
 }
 
 int security_binder_transaction(struct task_struct *from, struct task_struct *to)
 {
+	if (!security_binder_transaction_ptr)
+		security_binder_transaction_ptr = kallsyms_lookup_name("security_binder_transaction");
 	return security_binder_transaction_ptr(from, to);
 }
 
 int security_binder_transfer_binder(struct task_struct *from, struct task_struct *to)
 {
+	if (!security_binder_transfer_binder_ptr)
+		security_binder_transfer_binder_ptr = kallsyms_lookup_name("security_binder_transfer_binder");
 	return security_binder_transfer_binder_ptr(from, to);
 }
 
 int security_binder_transfer_file(struct task_struct *from, struct task_struct *to, struct file *file)
 {
+	if (!security_binder_transfer_file_ptr)
+		security_binder_transfer_file_ptr = kallsyms_lookup_name("security_binder_transfer_file");
 	return security_binder_transfer_file_ptr(from, to, file);
 }

kernel/binder/gen_deps.sh

-#!/bin/sh
-
-SYMS="get_vm_area zap_page_range map_kernel_range_noflush unmap_kernel_range "\
-"get_files_struct put_files_struct __lock_task_sighand "\
-"__alloc_fd __fd_install __close_fd can_nice "\
-"security_binder_set_context_mgr security_binder_transaction "\
-"security_binder_transfer_binder security_binder_transfer_file"
-
-for sym in $SYMS; do 
-	addr=`cat /proc/kallsyms | grep -Ee '^[0-9a-f]+ T '$sym'$' | sed -e 's/\s.*$//g'`
-	if [ a$addr = 'a' ]; then
-		echo "Error: can't find symbol $sym"
-		exit 1
-	fi
-
-	name=`echo $sym | tr '[:lower:]' '[:upper:]'`
-	echo "#define $name\t(void *)0x$addr"
-done