linux_dsm_epyc7002/arch/xtensa/kernel/signal.c
Chris Zankel fc4fb2adf9 [PATCH] xtensa: fix system call interface
This is a long outstanding patch to finally fix the syscall interface.  The
constants used for the system calls are those we have provided in our libc
patches.  This patch also fixes the shmbuf and stat structure, and fcntl
definitions.

Signed-off-by: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 09:55:39 -08:00

715 lines
18 KiB
C

// TODO coprocessor stuff
/*
* linux/arch/xtensa/kernel/signal.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
*
* Joe Taylor <joe@tensilica.com>
* Chris Zankel <chris@zankel.net>
*
*
*
*/
#include <asm/variant/core.h>
#include <asm/coprocessor.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/wait.h>
#include <linux/ptrace.h>
#include <linux/unistd.h>
#include <linux/stddef.h>
#include <linux/personality.h>
#include <asm/ucontext.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/cacheflush.h>
#define DEBUG_SIG 0
#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
asmlinkage long sys_wait4(pid_t pid,unsigned int * stat_addr, int options,
struct rusage * ru);
asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset);
extern struct task_struct *coproc_owners[];
/*
* Atomically swap in the new signal mask, and wait for a signal.
*/
int xtensa_sigsuspend(struct pt_regs *regs)
{
old_sigset_t mask = (old_sigset_t) regs->areg[3];
sigset_t saveset;
mask &= _BLOCKABLE;
spin_lock_irq(&current->sighand->siglock);
saveset = current->blocked;
siginitset(&current->blocked, mask);
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
regs->areg[2] = -EINTR;
while (1) {
current->state = TASK_INTERRUPTIBLE;
schedule();
if (do_signal(regs, &saveset))
return -EINTR;
}
}
asmlinkage int
xtensa_rt_sigsuspend(struct pt_regs *regs)
{
sigset_t *unewset = (sigset_t *) regs->areg[4];
size_t sigsetsize = (size_t) regs->areg[3];
sigset_t saveset, newset;
/* XXX: Don't preclude handling different sized sigset_t's. */
if (sigsetsize != sizeof(sigset_t))
return -EINVAL;
if (copy_from_user(&newset, unewset, sizeof(newset)))
return -EFAULT;
sigdelsetmask(&newset, ~_BLOCKABLE);
spin_lock_irq(&current->sighand->siglock);
saveset = current->blocked;
current->blocked = newset;
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
regs->areg[2] = -EINTR;
while (1) {
current->state = TASK_INTERRUPTIBLE;
schedule();
if (do_signal(regs, &saveset))
return -EINTR;
}
}
asmlinkage int
xtensa_sigaction(int sig, const struct old_sigaction *act,
struct old_sigaction *oact)
{
struct k_sigaction new_ka, old_ka;
int ret;
if (act) {
old_sigset_t mask;
if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
__get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
__get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
return -EFAULT;
__get_user(new_ka.sa.sa_flags, &act->sa_flags);
__get_user(mask, &act->sa_mask);
siginitset(&new_ka.sa.sa_mask, mask);
}
ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
if (!ret && oact) {
if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
__put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
__put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
return -EFAULT;
__put_user(old_ka.sa.sa_flags, &oact->sa_flags);
__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
}
return ret;
}
asmlinkage int
xtensa_sigaltstack(struct pt_regs *regs)
{
const stack_t *uss = (stack_t *) regs->areg[4];
stack_t *uoss = (stack_t *) regs->areg[3];
if (regs->depc > 64)
panic ("Double exception sys_sigreturn\n");
return do_sigaltstack(uss, uoss, regs->areg[1]);
}
/*
* Do a signal return; undo the signal stack.
*/
struct sigframe
{
struct sigcontext sc;
struct _cpstate cpstate;
unsigned long extramask[_NSIG_WORDS-1];
unsigned char retcode[6];
unsigned int reserved[4]; /* Reserved area for chaining */
unsigned int window[4]; /* Window of 4 registers for initial context */
};
struct rt_sigframe
{
struct siginfo info;
struct ucontext uc;
struct _cpstate cpstate;
unsigned char retcode[6];
unsigned int reserved[4]; /* Reserved area for chaining */
unsigned int window[4]; /* Window of 4 registers for initial context */
};
extern void release_all_cp (struct task_struct *);
// FIXME restore_cpextra
static inline int
restore_cpextra (struct _cpstate *buf)
{
#if 0
/* The signal handler may have used coprocessors in which
* case they are still enabled. We disable them to force a
* reloading of the original task's CP state by the lazy
* context-switching mechanisms of CP exception handling.
* Also, we essentially discard any coprocessor state that the
* signal handler created. */
struct task_struct *tsk = current;
release_all_cp(tsk);
return __copy_from_user(tsk->thread.cpextra, buf, XTENSA_CP_EXTRA_SIZE);
#endif
return 0;
}
/* Note: We don't copy double exception 'tregs', we have to finish double exc. first before we return to signal handler! This dbl.exc.handler might cause another double exception, but I think we are fine as the situation is the same as if we had returned to the signal handerl and got an interrupt immediately...
*/
static int
restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc)
{
struct thread_struct *thread;
unsigned int err = 0;
unsigned long ps;
struct _cpstate *buf;
#define COPY(x) err |= __get_user(regs->x, &sc->sc_##x)
COPY(pc);
COPY(depc);
COPY(wmask);
COPY(lbeg);
COPY(lend);
COPY(lcount);
COPY(sar);
COPY(windowbase);
COPY(windowstart);
#undef COPY
/* For PS, restore only PS.CALLINC.
* Assume that all other bits are either the same as for the signal
* handler, or the user mode value doesn't matter (e.g. PS.OWB).
*/
err |= __get_user(ps, &sc->sc_ps);
regs->ps = (regs->ps & ~PS_CALLINC_MASK)
| (ps & PS_CALLINC_MASK);
/* Additional corruption checks */
if ((regs->windowbase >= (XCHAL_NUM_AREGS/4))
|| ((regs->windowstart & ~((1<<(XCHAL_NUM_AREGS/4)) - 1)) != 0) )
err = 1;
if ((regs->lcount > 0)
&& ((regs->lbeg > TASK_SIZE) || (regs->lend > TASK_SIZE)) )
err = 1;
/* Restore extended register state.
* See struct thread_struct in processor.h.
*/
thread = &current->thread;
err |= __copy_from_user (regs->areg, sc->sc_areg, XCHAL_NUM_AREGS*4);
err |= __get_user(buf, &sc->sc_cpstate);
if (buf) {
if (!access_ok(VERIFY_READ, buf, sizeof(*buf)))
goto badframe;
err |= restore_cpextra(buf);
}
regs->syscall = -1; /* disable syscall checks */
return err;
badframe:
return 1;
}
static inline void
flush_my_cpstate(struct task_struct *tsk)
{
unsigned long flags;
local_irq_save(flags);
#if 0 // FIXME
for (i = 0; i < XCHAL_CP_NUM; i++) {
if (tsk == coproc_owners[i]) {
xthal_validate_cp(i);
xthal_save_cpregs(tsk->thread.cpregs_ptr[i], i);
/* Invalidate and "disown" the cp to allow
* callers the chance to reset cp state in the
* task_struct. */
xthal_invalidate_cp(i);
coproc_owners[i] = 0;
}
}
#endif
local_irq_restore(flags);
}
/* Return codes:
0: nothing saved
1: stuff to save, successful
-1: stuff to save, error happened
*/
static int
save_cpextra (struct _cpstate *buf)
{
#if XCHAL_CP_NUM == 0
return 0;
#else
/* FIXME: If a task has never used a coprocessor, there is
* no need to save and restore anything. Tracking this
* information would allow us to optimize this section.
* Perhaps we can use current->used_math or (current->flags &
* PF_USEDFPU) or define a new field in the thread
* structure. */
/* We flush any live, task-owned cp state to the task_struct,
* then copy it all to the sigframe. Then we clear all
* cp/extra state in the task_struct, effectively
* clearing/resetting all cp/extra state for the signal
* handler (cp-exception handling will load these new values
* into the cp/extra registers.) This step is important for
* things like a floating-point cp, where the OS must reset
* the FCR to the default rounding mode. */
int err = 0;
struct task_struct *tsk = current;
flush_my_cpstate(tsk);
/* Note that we just copy everything: 'extra' and 'cp' state together.*/
err |= __copy_to_user(buf, tsk->thread.cp_save, XTENSA_CP_EXTRA_SIZE);
memset(tsk->thread.cp_save, 0, XTENSA_CP_EXTRA_SIZE);
#if (XTENSA_CP_EXTRA_SIZE == 0)
#error Sanity check on memset above, cpextra_size should not be zero.
#endif
return err ? -1 : 1;
#endif
}
static int
setup_sigcontext(struct sigcontext *sc, struct _cpstate *cpstate,
struct pt_regs *regs, unsigned long mask)
{
struct thread_struct *thread;
int err = 0;
//printk("setup_sigcontext\n");
#define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
COPY(pc);
COPY(ps);
COPY(depc);
COPY(wmask);
COPY(lbeg);
COPY(lend);
COPY(lcount);
COPY(sar);
COPY(windowbase);
COPY(windowstart);
#undef COPY
/* Save extended register state.
* See struct thread_struct in processor.h.
*/
thread = &current->thread;
err |= __copy_to_user (sc->sc_areg, regs->areg, XCHAL_NUM_AREGS * 4);
err |= save_cpextra(cpstate);
err |= __put_user(err ? NULL : cpstate, &sc->sc_cpstate);
/* non-iBCS2 extensions.. */
err |= __put_user(mask, &sc->oldmask);
return err;
}
asmlinkage int xtensa_sigreturn(struct pt_regs *regs)
{
struct sigframe *frame = (struct sigframe *)regs->areg[1];
sigset_t set;
if (regs->depc > 64)
panic ("Double exception sys_sigreturn\n");
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__get_user(set.sig[0], &frame->sc.oldmask)
|| (_NSIG_WORDS > 1
&& __copy_from_user(&set.sig[1], &frame->extramask,
sizeof(frame->extramask))))
goto badframe;
sigdelsetmask(&set, ~_BLOCKABLE);
spin_lock_irq(&current->sighand->siglock);
current->blocked = set;
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
if (restore_sigcontext(regs, &frame->sc))
goto badframe;
return regs->areg[2];
badframe:
force_sig(SIGSEGV, current);
return 0;
}
asmlinkage int xtensa_rt_sigreturn(struct pt_regs *regs)
{
struct rt_sigframe *frame = (struct rt_sigframe *)regs->areg[1];
sigset_t set;
stack_t st;
int ret;
if (regs->depc > 64)
{
printk("!!!!!!! DEPC !!!!!!!\n");
return 0;
}
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
goto badframe;
sigdelsetmask(&set, ~_BLOCKABLE);
spin_lock_irq(&current->sighand->siglock);
current->blocked = set;
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
goto badframe;
ret = regs->areg[2];
if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st)))
goto badframe;
/* It is more difficult to avoid calling this function than to
call it and ignore errors. */
do_sigaltstack(&st, NULL, regs->areg[1]);
return ret;
badframe:
force_sig(SIGSEGV, current);
return 0;
}
/*
* Set up a signal frame.
*/
/*
* Determine which stack to use..
*/
static inline void *
get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
{
if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! sas_ss_flags(sp))
sp = current->sas_ss_sp + current->sas_ss_size;
return (void *)((sp - frame_size) & -16ul);
}
#define USE_SIGRETURN 0
#define USE_RT_SIGRETURN 1
static int
gen_return_code(unsigned char *codemem, unsigned int use_rt_sigreturn)
{
unsigned int retcall;
int err = 0;
#if 0
/* Ignoring SA_RESTORER for now; it's supposed to be obsolete,
* and the xtensa glibc doesn't use it.
*/
if (ka->sa.sa_flags & SA_RESTORER) {
regs->pr = (unsigned long) ka->sa.sa_restorer;
} else
#endif /* 0 */
{
#if (__NR_sigreturn > 255) || (__NR_rt_sigreturn > 255)
/* The 12-bit immediate is really split up within the 24-bit MOVI
* instruction. As long as the above system call numbers fit within
* 8-bits, the following code works fine. See the Xtensa ISA for
* details.
*/
#error Generating the MOVI instruction below breaks!
#endif
retcall = use_rt_sigreturn ? __NR_rt_sigreturn : __NR_sigreturn;
#ifdef __XTENSA_EB__ /* Big Endian version */
/* Generate instruction: MOVI a2, retcall */
err |= __put_user(0x22, &codemem[0]);
err |= __put_user(0x0a, &codemem[1]);
err |= __put_user(retcall, &codemem[2]);
/* Generate instruction: SYSCALL */
err |= __put_user(0x00, &codemem[3]);
err |= __put_user(0x05, &codemem[4]);
err |= __put_user(0x00, &codemem[5]);
#elif defined __XTENSA_EL__ /* Little Endian version */
/* Generate instruction: MOVI a2, retcall */
err |= __put_user(0x22, &codemem[0]);
err |= __put_user(0xa0, &codemem[1]);
err |= __put_user(retcall, &codemem[2]);
/* Generate instruction: SYSCALL */
err |= __put_user(0x00, &codemem[3]);
err |= __put_user(0x50, &codemem[4]);
err |= __put_user(0x00, &codemem[5]);
#else
#error Must use compiler for Xtensa processors.
#endif
}
/* Flush generated code out of the data cache */
if (err == 0) {
__invalidate_icache_range((unsigned long)codemem, 6UL);
__flush_invalidate_dcache_range((unsigned long)codemem, 6UL);
}
return err;
}
static void
set_thread_state(struct pt_regs *regs, void *stack, unsigned char *retaddr,
void *handler, unsigned long arg1, void *arg2, void *arg3)
{
/* Set up registers for signal handler */
start_thread(regs, (unsigned long) handler, (unsigned long) stack);
/* Set up a stack frame for a call4
* Note: PS.CALLINC is set to one by start_thread
*/
regs->areg[4] = (((unsigned long) retaddr) & 0x3fffffff) | 0x40000000;
regs->areg[6] = arg1;
regs->areg[7] = (unsigned long) arg2;
regs->areg[8] = (unsigned long) arg3;
}
static void setup_frame(int sig, struct k_sigaction *ka,
sigset_t *set, struct pt_regs *regs)
{
struct sigframe *frame;
int err = 0;
int signal;
frame = get_sigframe(ka, regs->areg[1], sizeof(*frame));
if (regs->depc > 64)
{
printk("!!!!!!! DEPC !!!!!!!\n");
return;
}
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
goto give_sigsegv;
signal = current_thread_info()->exec_domain
&& current_thread_info()->exec_domain->signal_invmap
&& sig < 32
? current_thread_info()->exec_domain->signal_invmap[sig]
: sig;
err |= setup_sigcontext(&frame->sc, &frame->cpstate, regs, set->sig[0]);
if (_NSIG_WORDS > 1) {
err |= __copy_to_user(frame->extramask, &set->sig[1],
sizeof(frame->extramask));
}
/* Create sys_sigreturn syscall in stack frame */
err |= gen_return_code(frame->retcode, USE_SIGRETURN);
if (err)
goto give_sigsegv;
/* Create signal handler execution context.
* Return context not modified until this point.
*/
set_thread_state(regs, frame, frame->retcode,
ka->sa.sa_handler, signal, &frame->sc, NULL);
/* Set access mode to USER_DS. Nomenclature is outdated, but
* functionality is used in uaccess.h
*/
set_fs(USER_DS);
#if DEBUG_SIG
printk("SIG deliver (%s:%d): signal=%d sp=%p pc=%08x\n",
current->comm, current->pid, signal, frame, regs->pc);
#endif
return;
give_sigsegv:
if (sig == SIGSEGV)
ka->sa.sa_handler = SIG_DFL;
force_sig(SIGSEGV, current);
}
static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
sigset_t *set, struct pt_regs *regs)
{
struct rt_sigframe *frame;
int err = 0;
int signal;
frame = get_sigframe(ka, regs->areg[1], sizeof(*frame));
if (regs->depc > 64)
panic ("Double exception sys_sigreturn\n");
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
goto give_sigsegv;
signal = current_thread_info()->exec_domain
&& current_thread_info()->exec_domain->signal_invmap
&& sig < 32
? current_thread_info()->exec_domain->signal_invmap[sig]
: sig;
err |= copy_siginfo_to_user(&frame->info, info);
/* Create the ucontext. */
err |= __put_user(0, &frame->uc.uc_flags);
err |= __put_user(0, &frame->uc.uc_link);
err |= __put_user((void *)current->sas_ss_sp,
&frame->uc.uc_stack.ss_sp);
err |= __put_user(sas_ss_flags(regs->areg[1]),
&frame->uc.uc_stack.ss_flags);
err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
err |= setup_sigcontext(&frame->uc.uc_mcontext, &frame->cpstate,
regs, set->sig[0]);
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
/* Create sys_rt_sigreturn syscall in stack frame */
err |= gen_return_code(frame->retcode, USE_RT_SIGRETURN);
if (err)
goto give_sigsegv;
/* Create signal handler execution context.
* Return context not modified until this point.
*/
set_thread_state(regs, frame, frame->retcode,
ka->sa.sa_handler, signal, &frame->info, &frame->uc);
/* Set access mode to USER_DS. Nomenclature is outdated, but
* functionality is used in uaccess.h
*/
set_fs(USER_DS);
#if DEBUG_SIG
printk("SIG rt deliver (%s:%d): signal=%d sp=%p pc=%08x\n",
current->comm, current->pid, signal, frame, regs->pc);
#endif
return;
give_sigsegv:
if (sig == SIGSEGV)
ka->sa.sa_handler = SIG_DFL;
force_sig(SIGSEGV, current);
}
/*
* Note that 'init' is a special process: it doesn't get signals it doesn't
* want to handle. Thus you cannot kill init even with a SIGKILL even by
* mistake.
*
* Note that we go through the signals twice: once to check the signals that
* the kernel can handle, and then we build all the user-level signal handling
* stack-frames in one go after that.
*/
int do_signal(struct pt_regs *regs, sigset_t *oldset)
{
siginfo_t info;
int signr;
struct k_sigaction ka;
if (!oldset)
oldset = &current->blocked;
signr = get_signal_to_deliver(&info, &ka, regs, NULL);
/* Are we from a system call? */
if (regs->syscall >= 0) {
/* If so, check system call restarting.. */
switch (regs->areg[2]) {
case ERESTARTNOHAND:
case ERESTART_RESTARTBLOCK:
regs->areg[2] = -EINTR;
break;
case ERESTARTSYS:
if (!(ka.sa.sa_flags & SA_RESTART)) {
regs->areg[2] = -EINTR;
break;
}
/* fallthrough */
case ERESTARTNOINTR:
regs->areg[2] = regs->syscall;
regs->pc -= 3;
}
}
if (signr == 0)
return 0; /* no signals delivered */
/* Whee! Actually deliver the signal. */
/* Set up the stack frame */
if (ka.sa.sa_flags & SA_SIGINFO)
setup_rt_frame(signr, &ka, &info, oldset, regs);
else
setup_frame(signr, &ka, oldset, regs);
if (ka.sa.sa_flags & SA_ONESHOT)
ka.sa.sa_handler = SIG_DFL;
spin_lock_irq(&current->sighand->siglock);
sigorsets(&current->blocked, &current->blocked, &ka.sa.sa_mask);
if (!(ka.sa.sa_flags & SA_NODEFER))
sigaddset(&current->blocked, signr);
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
return 1;
}