On 2024/8/27 6:49, Paul Moore wrote:
On Mon, Aug 26, 2024 at 8:05 AM Kaixiong Yu <yukaixiong@xxxxxxxxxx> wrote:
The dac_mmap_min_addr belongs to min_addr.c, move it into
its own file from /kernel/sysctl.c. In the previous Linux kernel
boot process, sysctl_init_bases needs to be executed before
init_mmap_min_addr, So, register_sysctl_init should be executed
before update_mmap_min_addr in init_mmap_min_addr.
Signed-off-by: Kaixiong Yu <yukaixiong@xxxxxxxxxx>
---
kernel/sysctl.c | 9 ---------
security/min_addr.c | 11 +++++++++++
2 files changed, 11 insertions(+), 9 deletions(-)
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 41d4afc978e6..0c0bab3dad7d 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2059,15 +2059,6 @@ static struct ctl_table vm_table[] = {
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
},
-#ifdef CONFIG_MMU
- {
- .procname = "mmap_min_addr",
- .data = &dac_mmap_min_addr,
- .maxlen = sizeof(unsigned long),
- .mode = 0644,
- .proc_handler = mmap_min_addr_handler,
- },
-#endif
#if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
(defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
{
diff --git a/security/min_addr.c b/security/min_addr.c
index 0ce267c041ab..b2f61649e110 100644
--- a/security/min_addr.c
+++ b/security/min_addr.c
@@ -44,8 +44,19 @@ int mmap_min_addr_handler(const struct ctl_table *table, int write,
return ret;
}
+static struct ctl_table min_addr_sysctl_table[] = {
+ {
+ .procname = "mmap_min_addr",
+ .data = &dac_mmap_min_addr,
+ .maxlen = sizeof(unsigned long),
+ .mode = 0644,
+ .proc_handler = mmap_min_addr_handler,
+ },
+};
I haven't chased all of the Kconfig deps to see if there is a problem,
but please provide a quick explanation in the commit description about
why it is okay to drop the CONFIG_MMU check.
According to the compilation condition in security/Makefile:
obj-$(CONFIG_MMU) += min_addr.o
if CONFIG_MMU is not defined, min_addr.c would not be included in the
compilation process.
So，it is okay to drop the CONFIG_MMU check.
static int __init init_mmap_min_addr(void)
{
+ register_sysctl_init("vm", min_addr_sysctl_table);
update_mmap_min_addr();
return 0;
--
2.25.1
