> From: "Theo de Raadt" <dera...@openbsd.org>
> Date: Mon, 30 Aug 2021 01:47:43 -0600
>
> Hang on, SYSCALL_DEBUG is used to bring up new architectures.
> That is the only time the #define is enabled.
>
> When you are bringing up a new architecture, bt is useless
>
> I don't think this makes sense.
Indeed. This needs to stay.
> Martin Pieuchot <m...@openbsd.org> wrote:
>
> > Now that dt(4) and btrace(8) are enabled by default and provide a nice
> > and flexible way to debug syscalls on GENERIC kernels should we get rid
> > of the SYSCALL_DEBUG mechanism?
> >
> > Note that the auto-generated kern/syscalls.c providing the `syscallnames'
> > array is still needed to build btrace(8).
> >
> > ok?
> >
> > Index: kern/exec_elf.c
> > ===================================================================
> > RCS file: /cvs/src/sys/kern/exec_elf.c,v
> > retrieving revision 1.160
> > diff -u -p -r1.160 exec_elf.c
> > --- kern/exec_elf.c 10 Mar 2021 10:21:47 -0000 1.160
> > +++ kern/exec_elf.c 30 Aug 2021 07:19:33 -0000
> > @@ -107,9 +107,6 @@ int elf_os_pt_note_name(Elf_Note *);
> > int elf_os_pt_note(struct proc *, struct exec_package *, Elf_Ehdr
> > *, int *);
> >
> > extern char sigcode[], esigcode[], sigcoderet[];
> > -#ifdef SYSCALL_DEBUG
> > -extern char *syscallnames[];
> > -#endif
> >
> > /* round up and down to page boundaries. */
> > #define ELF_ROUND(a, b) (((a) + (b) - 1) & ~((b) - 1))
> > @@ -135,11 +132,7 @@ struct emul emul_elf = {
> > SYS_syscall,
> > SYS_MAXSYSCALL,
> > sysent,
> > -#ifdef SYSCALL_DEBUG
> > - syscallnames,
> > -#else
> > NULL,
> > -#endif
> > (sizeof(AuxInfo) * ELF_AUX_ENTRIES / sizeof(char *)),
> > elf_copyargs,
> > setregs,
> > Index: kern/kern_xxx.c
> > ===================================================================
> > RCS file: /cvs/src/sys/kern/kern_xxx.c,v
> > retrieving revision 1.36
> > diff -u -p -r1.36 kern_xxx.c
> > --- kern/kern_xxx.c 2 Apr 2019 11:00:22 -0000 1.36
> > +++ kern/kern_xxx.c 30 Aug 2021 07:19:17 -0000
> > @@ -84,75 +84,3 @@ __stack_smash_handler(char func[], int d
> > panic("smashed stack in %s", func);
> > }
> > #endif
> > -
> > -#ifdef SYSCALL_DEBUG
> > -#include <sys/proc.h>
> > -
> > -#define SCDEBUG_CALLS 0x0001 /* show calls */
> > -#define SCDEBUG_RETURNS 0x0002 /* show returns */
> > -#define SCDEBUG_ALL 0x0004 /* even syscalls that are
> > implemented */
> > -#define SCDEBUG_SHOWARGS 0x0008 /* show arguments to calls */
> > -
> > -int scdebug = SCDEBUG_CALLS|SCDEBUG_RETURNS|SCDEBUG_SHOWARGS;
> > -
> > -void
> > -scdebug_call(struct proc *p, register_t code, const register_t args[])
> > -{
> > - struct process *pr;
> > - struct sysent *sy;
> > - struct emul *em;
> > - int i;
> > -
> > - if (!(scdebug & SCDEBUG_CALLS))
> > - return;
> > -
> > - pr = p->p_p;
> > - em = pr->ps_emul;
> > - sy = &em->e_sysent[code];
> > - if (!(scdebug & SCDEBUG_ALL || code < 0 || code >= em->e_nsysent ||
> > - sy->sy_call == sys_nosys))
> > - return;
> > -
> > - printf("proc %d (%s): %s num ", pr->ps_pid, pr->ps_comm, em->e_name);
> > - if (code < 0 || code >= em->e_nsysent)
> > - printf("OUT OF RANGE (%ld)", code);
> > - else {
> > - printf("%ld call: %s", code, em->e_syscallnames[code]);
> > - if (scdebug & SCDEBUG_SHOWARGS) {
> > - printf("(");
> > - for (i = 0; i < sy->sy_argsize / sizeof(register_t);
> > - i++)
> > - printf("%s0x%lx", i == 0 ? "" : ", ", args[i]);
> > - printf(")");
> > - }
> > - }
> > - printf("\n");
> > -}
> > -
> > -void
> > -scdebug_ret(struct proc *p, register_t code, int error,
> > - const register_t retval[])
> > -{
> > - struct process *pr;
> > - struct sysent *sy;
> > - struct emul *em;
> > -
> > - if (!(scdebug & SCDEBUG_RETURNS))
> > - return;
> > -
> > - pr = p->p_p;
> > - em = pr->ps_emul;
> > - sy = &em->e_sysent[code];
> > - if (!(scdebug & SCDEBUG_ALL || code < 0 || code >= em->e_nsysent ||
> > - sy->sy_call == sys_nosys))
> > - return;
> > -
> > - printf("proc %d (%s): %s num ", pr->ps_pid, pr->ps_comm, em->e_name);
> > - if (code < 0 || code >= em->e_nsysent)
> > - printf("OUT OF RANGE (%ld)", code);
> > - else
> > - printf("%ld ret: err = %d, rv = 0x%lx,0x%lx", code,
> > - error, retval[0], retval[1]);
> > - printf("\n");
> > -}
> > -#endif /* SYSCALL_DEBUG */
> > Index: kern/init_main.c
> > ===================================================================
> > RCS file: /cvs/src/sys/kern/init_main.c,v
> > retrieving revision 1.308
> > diff -u -p -r1.308 init_main.c
> > --- kern/init_main.c 30 Jun 2021 12:21:02 -0000 1.308
> > +++ kern/init_main.c 30 Aug 2021 07:17:55 -0000
> > @@ -155,9 +155,6 @@ void pool_gc_pages(void *);
> > void percpu_init(void);
> >
> > extern char sigcode[], esigcode[], sigcoderet[];
> > -#ifdef SYSCALL_DEBUG
> > -extern char *syscallnames[];
> > -#endif
> >
> > struct emul emul_native = {
> > "native",
> > @@ -165,11 +162,7 @@ struct emul emul_native = {
> > SYS_syscall,
> > SYS_MAXSYSCALL,
> > sysent,
> > -#ifdef SYSCALL_DEBUG
> > - syscallnames,
> > -#else
> > NULL,
> > -#endif
> > 0,
> > copyargs,
> > setregs,
> > Index: sys/systm.h
> > ===================================================================
> > RCS file: /cvs/src/sys/sys/systm.h,v
> > retrieving revision 1.154
> > diff -u -p -r1.154 systm.h
> > --- sys/systm.h 2 Jun 2021 00:39:25 -0000 1.154
> > +++ sys/systm.h 30 Aug 2021 07:18:06 -0000
> > @@ -131,12 +131,6 @@ extern struct sysent { /* system call t
> > #error "what byte order is this machine?"
> > #endif
> >
> > -#if defined(_KERNEL) && defined(SYSCALL_DEBUG)
> > -void scdebug_call(struct proc *p, register_t code, const register_t
> > retval[]);
> > -void scdebug_ret(struct proc *p, register_t code, int error,
> > - const register_t retval[]);
> > -#endif /* _KERNEL && SYSCALL_DEBUG */
> > -
> > extern int boothowto; /* reboot flags, from console subsystem
> > */
> >
> > extern void (*v_putc)(int); /* Virtual console putc routine */
> > Index: sys/syscall_mi.h
> > ===================================================================
> > RCS file: /cvs/src/sys/sys/syscall_mi.h,v
> > retrieving revision 1.25
> > diff -u -p -r1.25 syscall_mi.h
> > --- sys/syscall_mi.h 21 Jan 2020 16:16:23 -0000 1.25
> > +++ sys/syscall_mi.h 30 Aug 2021 07:19:10 -0000
> > @@ -60,11 +60,6 @@ mi_syscall(struct proc *p, register_t co
> > /* refresh the thread's cache of the process's creds */
> > refreshcreds(p);
> >
> > -#ifdef SYSCALL_DEBUG
> > - KERNEL_LOCK();
> > - scdebug_call(p, code, argp);
> > - KERNEL_UNLOCK();
> > -#endif
> > TRACEPOINT(raw_syscalls, sys_enter, code, NULL);
> > #if NDT > 0
> > DT_ENTER(syscall, code, callp->sy_argsize, argp);
> > @@ -113,11 +108,6 @@ static inline void
> > mi_syscall_return(struct proc *p, register_t code, int error,
> > const register_t retval[2])
> > {
> > -#ifdef SYSCALL_DEBUG
> > - KERNEL_LOCK();
> > - scdebug_ret(p, code, error, retval);
> > - KERNEL_UNLOCK();
> > -#endif
> > #if NDT > 0
> > DT_LEAVE(syscall, code, error, retval[0], retval[1]);
> > #endif
> > @@ -140,7 +130,7 @@ mi_syscall_return(struct proc *p, regist
> > static inline void
> > mi_child_return(struct proc *p)
> > {
> > -#if defined(SYSCALL_DEBUG) || defined(KTRACE) || NDT > 0
> > +#if defined(KTRACE) || NDT > 0
> > int code = (p->p_flag & P_THREAD) ? SYS___tfork :
> > (p->p_p->ps_flags & PS_PPWAIT) ? SYS_vfork : SYS_fork;
> > const register_t child_retval[2] = { 0, 1 };
> > @@ -148,11 +138,6 @@ mi_child_return(struct proc *p)
> >
> > TRACEPOINT(sched, on__cpu, NULL);
> >
> > -#ifdef SYSCALL_DEBUG
> > - KERNEL_LOCK();
> > - scdebug_ret(p, code, 0, child_retval);
> > - KERNEL_UNLOCK();
> > -#endif
> > #if NDT > 0
> > DT_LEAVE(syscall, code, 0, child_retval[0], child_retval[1]);
> > #endif
> >
>
>
