kallsyms: move kallsyms_show_value() out of kallsyms.c

function kallsyms_show_value() is used by other parts
like modules_open(), kprobes_read() etc. which can work in case of
!KALLSYMS also.

e.g. as of now lsmod do not show module address if KALLSYMS is disabled.
since kallsyms_show_value() defination is not present, it returns false
in !KALLSYMS.

/ # lsmod
test 12288 0 - Live 0x0000000000000000 (O)

So kallsyms_show_value() can be made generic
without dependency on KALLSYMS.

Thus moving out function to a new file ksyms_common.c.

With this patch code is just moved to new file
and no functional change.

Co-developed-by: Onkarnath <onkarnath.1@samsung.com>
Signed-off-by: Onkarnath <onkarnath.1@samsung.com>
Signed-off-by: Maninder Singh <maninder1.s@samsung.com>
Reviewed-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

diff --git a/kernel/Makefile b/kernel/Makefile
index b69c953..e7e63bb 100644 (file)
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -10,7 +10,7 @@ obj-y     = fork.o exec_domain.o panic.o \
            extable.o params.o \
            kthread.o sys_ni.o nsproxy.o \
            notifier.o ksysfs.o cred.o reboot.o \
-           async.o range.o smpboot.o ucount.o regset.o
+           async.o range.o smpboot.o ucount.o regset.o ksyms_common.o
 
 obj-$(CONFIG_USERMODE_DRIVER) += usermode_driver.o
 obj-$(CONFIG_MULTIUSER) += groups.o

diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 8193e94..0f82c3d 100644 (file)
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -907,41 +907,6 @@ late_initcall(bpf_ksym_iter_register);
 
 #endif /* CONFIG_BPF_SYSCALL */
 
-static inline int kallsyms_for_perf(void)
-{
-#ifdef CONFIG_PERF_EVENTS
-       extern int sysctl_perf_event_paranoid;
-       if (sysctl_perf_event_paranoid <= 1)
-               return 1;
-#endif
-       return 0;
-}
-
-/*
- * We show kallsyms information even to normal users if we've enabled
- * kernel profiling and are explicitly not paranoid (so kptr_restrict
- * is clear, and sysctl_perf_event_paranoid isn't set).
- *
- * Otherwise, require CAP_SYSLOG (assuming kptr_restrict isn't set to
- * block even that).
- */
-bool kallsyms_show_value(const struct cred *cred)
-{
-       switch (kptr_restrict) {
-       case 0:
-               if (kallsyms_for_perf())
-                       return true;
-               fallthrough;
-       case 1:
-               if (security_capable(cred, &init_user_ns, CAP_SYSLOG,
-                                    CAP_OPT_NOAUDIT) == 0)
-                       return true;
-               fallthrough;
-       default:
-               return false;
-       }
-}
-
 static int kallsyms_open(struct inode *inode, struct file *file)
 {
        /*

diff --git a/kernel/ksyms_common.c b/kernel/ksyms_common.c
new file mode 100644 (file)
index 0000000..3840fa1
--- /dev/null
+++ b/kernel/ksyms_common.c
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ksyms_common.c: A split of kernel/kallsyms.c
+ * Contains a few generic function definations independent of config KALLSYMS.
+ */
+#include <linux/kallsyms.h>
+#include <linux/security.h>
+
+#ifdef CONFIG_KALLSYMS
+static inline int kallsyms_for_perf(void)
+{
+#ifdef CONFIG_PERF_EVENTS
+       extern int sysctl_perf_event_paranoid;
+
+       if (sysctl_perf_event_paranoid <= 1)
+               return 1;
+#endif
+       return 0;
+}
+
+/*
+ * We show kallsyms information even to normal users if we've enabled
+ * kernel profiling and are explicitly not paranoid (so kptr_restrict
+ * is clear, and sysctl_perf_event_paranoid isn't set).
+ *
+ * Otherwise, require CAP_SYSLOG (assuming kptr_restrict isn't set to
+ * block even that).
+ */
+bool kallsyms_show_value(const struct cred *cred)
+{
+       switch (kptr_restrict) {
+       case 0:
+               if (kallsyms_for_perf())
+                       return true;
+               fallthrough;
+       case 1:
+               if (security_capable(cred, &init_user_ns, CAP_SYSLOG,
+                                    CAP_OPT_NOAUDIT) == 0)
+                       return true;
+               fallthrough;
+       default:
+               return false;
+       }
+}
+#endif