On 2020/6/9 23:40, Kees Cook wrote:
On Tue, Jun 09, 2020 at 02:20:05PM +0800, Xiaoming Ni wrote:
Since the commit 61a47c1ad3a4dc ("sysctl: Remove the sysctl system call"),
sys_sysctl has lost its actual role: any input can only return an error.
Delete the code and return -ENOSYS directly at the function entry
Signed-off-by: Xiaoming Ni <nixiaom...@huawei.com>
Looks right to me.
Reviewed-by: Kees Cook <keesc...@chromium.org>
Should this be taken a step further and just remove the syscall entirely
and update the per-arch tables with the ENOSYS hole?
-Kees
Searching for git log, I found a commit record that deleted syscall:
commit f5b94099739722 ("All Arch: remove linkage for sys_nfsservctl
system call"). Could I use sys_ni_syscall to implement the hole as in
the example here?
E.g:
diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl
index 7b3832d..f36fda6 100644
--- a/arch/arm/tools/syscall.tbl
+++ b/arch/arm/tools/syscall.tbl
@@ -162,7 +162,7 @@
146 common writev sys_writev
147 common getsid sys_getsid
148 common fdatasync sys_fdatasync
-149 common _sysctl sys_sysctl
+149 common _sysctl sys_ni_syscall
150 common mlock sys_mlock
151 common munlock sys_munlock
152 common mlockall sys_mlockall
diff --git a/arch/arm64/include/asm/unistd32.h
b/arch/arm64/include/asm/unistd32.h
index f8dafe9..ca41bb7 100644
--- a/arch/arm64/include/asm/unistd32.h
+++ b/arch/arm64/include/asm/unistd32.h
@@ -308,8 +308,8 @@
__SYSCALL(__NR_getsid, sys_getsid)
#define __NR_fdatasync 148
__SYSCALL(__NR_fdatasync, sys_fdatasync)
-#define __NR__sysctl 149
-__SYSCALL(__NR__sysctl, compat_sys_sysctl)
+ /* 149 was sys_sysctl */
+__SYSCALL(149, sys_ni_syscall)
#define __NR_mlock 150
__SYSCALL(__NR_mlock, sys_mlock)
#define __NR_munlock 151
In this case, I need to modify a lot of code in v2. Can I add
"Reviewed-by: Kees Cook <keesc...@chromium.org>" to the v2 patch?
Thanks
Xiaoming Ni
