I noticed that we don't have tracepoints for sys_modify_ldt(). I think that's because we define it directly instead of using the normal SYSCALL_DEFINEx() macros.
Is there a reason for that, or were they just missed when the macros were created? Cc: x...@kernel.org Cc: Andy Lutomirski <l...@kernel.org> --- b/arch/x86/include/asm/syscalls.h | 2 +- b/arch/x86/kernel/ldt.c | 5 +++-- b/arch/x86/um/ldt.c | 3 ++- 3 files changed, 6 insertions(+), 4 deletions(-) diff -puN arch/x86/kernel/ldt.c~x86-syscall-macros-modify_ldt arch/x86/kernel/ldt.c --- a/arch/x86/kernel/ldt.c~x86-syscall-macros-modify_ldt 2017-10-13 13:30:12.802553391 -0700 +++ b/arch/x86/kernel/ldt.c 2017-10-13 13:30:12.817553391 -0700 @@ -12,6 +12,7 @@ #include <linux/string.h> #include <linux/mm.h> #include <linux/smp.h> +#include <linux/syscalls.h> #include <linux/slab.h> #include <linux/vmalloc.h> #include <linux/uaccess.h> @@ -294,8 +295,8 @@ out: return error; } -asmlinkage int sys_modify_ldt(int func, void __user *ptr, - unsigned long bytecount) +SYSCALL_DEFINE3(modify_ldt, int , func , void __user * , ptr , + unsigned long , bytecount) { int ret = -ENOSYS; diff -puN arch/x86/include/asm/syscalls.h~x86-syscall-macros-modify_ldt arch/x86/include/asm/syscalls.h --- a/arch/x86/include/asm/syscalls.h~x86-syscall-macros-modify_ldt 2017-10-13 13:30:12.812553391 -0700 +++ b/arch/x86/include/asm/syscalls.h 2017-10-13 13:30:12.818553391 -0700 @@ -21,7 +21,7 @@ asmlinkage long sys_ioperm(unsigned long asmlinkage long sys_iopl(unsigned int); /* kernel/ldt.c */ -asmlinkage int sys_modify_ldt(int, void __user *, unsigned long); +asmlinkage long sys_modify_ldt(int, void __user *, unsigned long); /* kernel/signal.c */ asmlinkage long sys_rt_sigreturn(void); diff -puN arch/x86/um/ldt.c~x86-syscall-macros-modify_ldt arch/x86/um/ldt.c --- a/arch/x86/um/ldt.c~x86-syscall-macros-modify_ldt 2017-10-13 13:30:12.814553391 -0700 +++ b/arch/x86/um/ldt.c 2017-10-13 13:30:12.818553391 -0700 @@ -369,7 +369,8 @@ void free_ldt(struct mm_context *mm) mm->arch.ldt.entry_count = 0; } -int sys_modify_ldt(int func, void __user *ptr, unsigned long bytecount) +SYSCALL_DEFINE3(modify_ldt, int , func , void __user * , ptr , + unsigned long , bytecount) { return do_modify_ldt_skas(func, ptr, bytecount); } _