forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
565 lines
15 KiB
565 lines
15 KiB
// SPDX-License-Identifier: GPL-2.0 |
|
/* linux/arch/sparc/kernel/signal.c |
|
* |
|
* Copyright (C) 1991, 1992 Linus Torvalds |
|
* Copyright (C) 1995 David S. Miller ([email protected]) |
|
* Copyright (C) 1996 Miguel de Icaza ([email protected]) |
|
* Copyright (C) 1997 Eddie C. Dost ([email protected]) |
|
*/ |
|
|
|
#include <linux/sched.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/mm.h> |
|
#include <linux/tty.h> |
|
#include <linux/smp.h> |
|
#include <linux/binfmts.h> /* do_coredum */ |
|
#include <linux/bitops.h> |
|
#include <linux/tracehook.h> |
|
|
|
#include <linux/uaccess.h> |
|
#include <asm/ptrace.h> |
|
#include <asm/cacheflush.h> /* flush_sig_insns */ |
|
#include <asm/switch_to.h> |
|
|
|
#include "sigutil.h" |
|
#include "kernel.h" |
|
|
|
extern void fpsave(unsigned long *fpregs, unsigned long *fsr, |
|
void *fpqueue, unsigned long *fpqdepth); |
|
extern void fpload(unsigned long *fpregs, unsigned long *fsr); |
|
|
|
struct signal_frame { |
|
struct sparc_stackf ss; |
|
__siginfo32_t info; |
|
__siginfo_fpu_t __user *fpu_save; |
|
unsigned long insns[2] __attribute__ ((aligned (8))); |
|
unsigned int extramask[_NSIG_WORDS - 1]; |
|
unsigned int extra_size; /* Should be 0 */ |
|
__siginfo_rwin_t __user *rwin_save; |
|
} __attribute__((aligned(8))); |
|
|
|
struct rt_signal_frame { |
|
struct sparc_stackf ss; |
|
siginfo_t info; |
|
struct pt_regs regs; |
|
sigset_t mask; |
|
__siginfo_fpu_t __user *fpu_save; |
|
unsigned int insns[2]; |
|
stack_t stack; |
|
unsigned int extra_size; /* Should be 0 */ |
|
__siginfo_rwin_t __user *rwin_save; |
|
} __attribute__((aligned(8))); |
|
|
|
/* Align macros */ |
|
#define SF_ALIGNEDSZ (((sizeof(struct signal_frame) + 7) & (~7))) |
|
#define RT_ALIGNEDSZ (((sizeof(struct rt_signal_frame) + 7) & (~7))) |
|
|
|
/* Checks if the fp is valid. We always build signal frames which are |
|
* 16-byte aligned, therefore we can always enforce that the restore |
|
* frame has that property as well. |
|
*/ |
|
static inline bool invalid_frame_pointer(void __user *fp, int fplen) |
|
{ |
|
if ((((unsigned long) fp) & 15) || !__access_ok((unsigned long)fp, fplen)) |
|
return true; |
|
|
|
return false; |
|
} |
|
|
|
asmlinkage void do_sigreturn(struct pt_regs *regs) |
|
{ |
|
unsigned long up_psr, pc, npc, ufp; |
|
struct signal_frame __user *sf; |
|
sigset_t set; |
|
__siginfo_fpu_t __user *fpu_save; |
|
__siginfo_rwin_t __user *rwin_save; |
|
int err; |
|
|
|
/* Always make any pending restarted system calls return -EINTR */ |
|
current->restart_block.fn = do_no_restart_syscall; |
|
|
|
synchronize_user_stack(); |
|
|
|
sf = (struct signal_frame __user *) regs->u_regs[UREG_FP]; |
|
|
|
/* 1. Make sure we are not getting garbage from the user */ |
|
if (invalid_frame_pointer(sf, sizeof(*sf))) |
|
goto segv_and_exit; |
|
|
|
if (get_user(ufp, &sf->info.si_regs.u_regs[UREG_FP])) |
|
goto segv_and_exit; |
|
|
|
if (ufp & 0x7) |
|
goto segv_and_exit; |
|
|
|
err = __get_user(pc, &sf->info.si_regs.pc); |
|
err |= __get_user(npc, &sf->info.si_regs.npc); |
|
|
|
if ((pc | npc) & 3) |
|
goto segv_and_exit; |
|
|
|
/* 2. Restore the state */ |
|
up_psr = regs->psr; |
|
err |= __copy_from_user(regs, &sf->info.si_regs, sizeof(struct pt_regs)); |
|
|
|
/* User can only change condition codes and FPU enabling in %psr. */ |
|
regs->psr = (up_psr & ~(PSR_ICC | PSR_EF)) |
|
| (regs->psr & (PSR_ICC | PSR_EF)); |
|
|
|
/* Prevent syscall restart. */ |
|
pt_regs_clear_syscall(regs); |
|
|
|
err |= __get_user(fpu_save, &sf->fpu_save); |
|
if (fpu_save) |
|
err |= restore_fpu_state(regs, fpu_save); |
|
err |= __get_user(rwin_save, &sf->rwin_save); |
|
if (rwin_save) |
|
err |= restore_rwin_state(rwin_save); |
|
|
|
/* This is pretty much atomic, no amount locking would prevent |
|
* the races which exist anyways. |
|
*/ |
|
err |= __get_user(set.sig[0], &sf->info.si_mask); |
|
err |= __copy_from_user(&set.sig[1], &sf->extramask, |
|
(_NSIG_WORDS-1) * sizeof(unsigned int)); |
|
|
|
if (err) |
|
goto segv_and_exit; |
|
|
|
set_current_blocked(&set); |
|
return; |
|
|
|
segv_and_exit: |
|
force_sig(SIGSEGV); |
|
} |
|
|
|
asmlinkage void do_rt_sigreturn(struct pt_regs *regs) |
|
{ |
|
struct rt_signal_frame __user *sf; |
|
unsigned int psr, pc, npc, ufp; |
|
__siginfo_fpu_t __user *fpu_save; |
|
__siginfo_rwin_t __user *rwin_save; |
|
sigset_t set; |
|
int err; |
|
|
|
synchronize_user_stack(); |
|
sf = (struct rt_signal_frame __user *) regs->u_regs[UREG_FP]; |
|
if (invalid_frame_pointer(sf, sizeof(*sf))) |
|
goto segv; |
|
|
|
if (get_user(ufp, &sf->regs.u_regs[UREG_FP])) |
|
goto segv; |
|
|
|
if (ufp & 0x7) |
|
goto segv; |
|
|
|
err = __get_user(pc, &sf->regs.pc); |
|
err |= __get_user(npc, &sf->regs.npc); |
|
err |= ((pc | npc) & 0x03); |
|
|
|
err |= __get_user(regs->y, &sf->regs.y); |
|
err |= __get_user(psr, &sf->regs.psr); |
|
|
|
err |= __copy_from_user(®s->u_regs[UREG_G1], |
|
&sf->regs.u_regs[UREG_G1], 15 * sizeof(u32)); |
|
|
|
regs->psr = (regs->psr & ~PSR_ICC) | (psr & PSR_ICC); |
|
|
|
/* Prevent syscall restart. */ |
|
pt_regs_clear_syscall(regs); |
|
|
|
err |= __get_user(fpu_save, &sf->fpu_save); |
|
if (!err && fpu_save) |
|
err |= restore_fpu_state(regs, fpu_save); |
|
err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t)); |
|
err |= restore_altstack(&sf->stack); |
|
|
|
if (err) |
|
goto segv; |
|
|
|
regs->pc = pc; |
|
regs->npc = npc; |
|
|
|
err |= __get_user(rwin_save, &sf->rwin_save); |
|
if (!err && rwin_save) { |
|
if (restore_rwin_state(rwin_save)) |
|
goto segv; |
|
} |
|
|
|
set_current_blocked(&set); |
|
return; |
|
segv: |
|
force_sig(SIGSEGV); |
|
} |
|
|
|
static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize) |
|
{ |
|
unsigned long sp = regs->u_regs[UREG_FP]; |
|
|
|
/* |
|
* If we are on the alternate signal stack and would overflow it, don't. |
|
* Return an always-bogus address instead so we will die with SIGSEGV. |
|
*/ |
|
if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize))) |
|
return (void __user *) -1L; |
|
|
|
/* This is the X/Open sanctioned signal stack switching. */ |
|
sp = sigsp(sp, ksig) - framesize; |
|
|
|
/* Always align the stack frame. This handles two cases. First, |
|
* sigaltstack need not be mindful of platform specific stack |
|
* alignment. Second, if we took this signal because the stack |
|
* is not aligned properly, we'd like to take the signal cleanly |
|
* and report that. |
|
*/ |
|
sp &= ~15UL; |
|
|
|
return (void __user *) sp; |
|
} |
|
|
|
static int setup_frame(struct ksignal *ksig, struct pt_regs *regs, |
|
sigset_t *oldset) |
|
{ |
|
struct signal_frame __user *sf; |
|
int sigframe_size, err, wsaved; |
|
void __user *tail; |
|
|
|
/* 1. Make sure everything is clean */ |
|
synchronize_user_stack(); |
|
|
|
wsaved = current_thread_info()->w_saved; |
|
|
|
sigframe_size = sizeof(*sf); |
|
if (used_math()) |
|
sigframe_size += sizeof(__siginfo_fpu_t); |
|
if (wsaved) |
|
sigframe_size += sizeof(__siginfo_rwin_t); |
|
|
|
sf = (struct signal_frame __user *) |
|
get_sigframe(ksig, regs, sigframe_size); |
|
|
|
if (invalid_frame_pointer(sf, sigframe_size)) { |
|
do_exit(SIGILL); |
|
return -EINVAL; |
|
} |
|
|
|
tail = sf + 1; |
|
|
|
/* 2. Save the current process state */ |
|
err = __copy_to_user(&sf->info.si_regs, regs, sizeof(struct pt_regs)); |
|
|
|
err |= __put_user(0, &sf->extra_size); |
|
|
|
if (used_math()) { |
|
__siginfo_fpu_t __user *fp = tail; |
|
tail += sizeof(*fp); |
|
err |= save_fpu_state(regs, fp); |
|
err |= __put_user(fp, &sf->fpu_save); |
|
} else { |
|
err |= __put_user(0, &sf->fpu_save); |
|
} |
|
if (wsaved) { |
|
__siginfo_rwin_t __user *rwp = tail; |
|
tail += sizeof(*rwp); |
|
err |= save_rwin_state(wsaved, rwp); |
|
err |= __put_user(rwp, &sf->rwin_save); |
|
} else { |
|
err |= __put_user(0, &sf->rwin_save); |
|
} |
|
|
|
err |= __put_user(oldset->sig[0], &sf->info.si_mask); |
|
err |= __copy_to_user(sf->extramask, &oldset->sig[1], |
|
(_NSIG_WORDS - 1) * sizeof(unsigned int)); |
|
if (!wsaved) { |
|
err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP], |
|
sizeof(struct reg_window32)); |
|
} else { |
|
struct reg_window32 *rp; |
|
|
|
rp = ¤t_thread_info()->reg_window[wsaved - 1]; |
|
err |= __copy_to_user(sf, rp, sizeof(struct reg_window32)); |
|
} |
|
if (err) |
|
return err; |
|
|
|
/* 3. signal handler back-trampoline and parameters */ |
|
regs->u_regs[UREG_FP] = (unsigned long) sf; |
|
regs->u_regs[UREG_I0] = ksig->sig; |
|
regs->u_regs[UREG_I1] = (unsigned long) &sf->info; |
|
regs->u_regs[UREG_I2] = (unsigned long) &sf->info; |
|
|
|
/* 4. signal handler */ |
|
regs->pc = (unsigned long) ksig->ka.sa.sa_handler; |
|
regs->npc = (regs->pc + 4); |
|
|
|
/* 5. return to kernel instructions */ |
|
if (ksig->ka.ka_restorer) |
|
regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer; |
|
else { |
|
regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2); |
|
|
|
/* mov __NR_sigreturn, %g1 */ |
|
err |= __put_user(0x821020d8, &sf->insns[0]); |
|
|
|
/* t 0x10 */ |
|
err |= __put_user(0x91d02010, &sf->insns[1]); |
|
if (err) |
|
return err; |
|
|
|
/* Flush instruction space. */ |
|
flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0])); |
|
} |
|
return 0; |
|
} |
|
|
|
static int setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs, |
|
sigset_t *oldset) |
|
{ |
|
struct rt_signal_frame __user *sf; |
|
int sigframe_size, wsaved; |
|
void __user *tail; |
|
unsigned int psr; |
|
int err; |
|
|
|
synchronize_user_stack(); |
|
wsaved = current_thread_info()->w_saved; |
|
sigframe_size = sizeof(*sf); |
|
if (used_math()) |
|
sigframe_size += sizeof(__siginfo_fpu_t); |
|
if (wsaved) |
|
sigframe_size += sizeof(__siginfo_rwin_t); |
|
sf = (struct rt_signal_frame __user *) |
|
get_sigframe(ksig, regs, sigframe_size); |
|
if (invalid_frame_pointer(sf, sigframe_size)) { |
|
do_exit(SIGILL); |
|
return -EINVAL; |
|
} |
|
|
|
tail = sf + 1; |
|
err = __put_user(regs->pc, &sf->regs.pc); |
|
err |= __put_user(regs->npc, &sf->regs.npc); |
|
err |= __put_user(regs->y, &sf->regs.y); |
|
psr = regs->psr; |
|
if (used_math()) |
|
psr |= PSR_EF; |
|
err |= __put_user(psr, &sf->regs.psr); |
|
err |= __copy_to_user(&sf->regs.u_regs, regs->u_regs, sizeof(regs->u_regs)); |
|
err |= __put_user(0, &sf->extra_size); |
|
|
|
if (psr & PSR_EF) { |
|
__siginfo_fpu_t __user *fp = tail; |
|
tail += sizeof(*fp); |
|
err |= save_fpu_state(regs, fp); |
|
err |= __put_user(fp, &sf->fpu_save); |
|
} else { |
|
err |= __put_user(0, &sf->fpu_save); |
|
} |
|
if (wsaved) { |
|
__siginfo_rwin_t __user *rwp = tail; |
|
tail += sizeof(*rwp); |
|
err |= save_rwin_state(wsaved, rwp); |
|
err |= __put_user(rwp, &sf->rwin_save); |
|
} else { |
|
err |= __put_user(0, &sf->rwin_save); |
|
} |
|
err |= __copy_to_user(&sf->mask, &oldset->sig[0], sizeof(sigset_t)); |
|
|
|
/* Setup sigaltstack */ |
|
err |= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]); |
|
|
|
if (!wsaved) { |
|
err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP], |
|
sizeof(struct reg_window32)); |
|
} else { |
|
struct reg_window32 *rp; |
|
|
|
rp = ¤t_thread_info()->reg_window[wsaved - 1]; |
|
err |= __copy_to_user(sf, rp, sizeof(struct reg_window32)); |
|
} |
|
|
|
err |= copy_siginfo_to_user(&sf->info, &ksig->info); |
|
|
|
if (err) |
|
return err; |
|
|
|
regs->u_regs[UREG_FP] = (unsigned long) sf; |
|
regs->u_regs[UREG_I0] = ksig->sig; |
|
regs->u_regs[UREG_I1] = (unsigned long) &sf->info; |
|
regs->u_regs[UREG_I2] = (unsigned long) &sf->regs; |
|
|
|
regs->pc = (unsigned long) ksig->ka.sa.sa_handler; |
|
regs->npc = (regs->pc + 4); |
|
|
|
if (ksig->ka.ka_restorer) |
|
regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer; |
|
else { |
|
regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2); |
|
|
|
/* mov __NR_rt_sigreturn, %g1 */ |
|
err |= __put_user(0x82102065, &sf->insns[0]); |
|
|
|
/* t 0x10 */ |
|
err |= __put_user(0x91d02010, &sf->insns[1]); |
|
if (err) |
|
return err; |
|
|
|
/* Flush instruction space. */ |
|
flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0])); |
|
} |
|
return 0; |
|
} |
|
|
|
static inline void |
|
handle_signal(struct ksignal *ksig, struct pt_regs *regs) |
|
{ |
|
sigset_t *oldset = sigmask_to_save(); |
|
int err; |
|
|
|
if (ksig->ka.sa.sa_flags & SA_SIGINFO) |
|
err = setup_rt_frame(ksig, regs, oldset); |
|
else |
|
err = setup_frame(ksig, regs, oldset); |
|
signal_setup_done(err, ksig, 0); |
|
} |
|
|
|
static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs, |
|
struct sigaction *sa) |
|
{ |
|
switch(regs->u_regs[UREG_I0]) { |
|
case ERESTART_RESTARTBLOCK: |
|
case ERESTARTNOHAND: |
|
no_system_call_restart: |
|
regs->u_regs[UREG_I0] = EINTR; |
|
regs->psr |= PSR_C; |
|
break; |
|
case ERESTARTSYS: |
|
if (!(sa->sa_flags & SA_RESTART)) |
|
goto no_system_call_restart; |
|
fallthrough; |
|
case ERESTARTNOINTR: |
|
regs->u_regs[UREG_I0] = orig_i0; |
|
regs->pc -= 4; |
|
regs->npc -= 4; |
|
} |
|
} |
|
|
|
/* 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. |
|
*/ |
|
static void do_signal(struct pt_regs *regs, unsigned long orig_i0) |
|
{ |
|
struct ksignal ksig; |
|
int restart_syscall; |
|
bool has_handler; |
|
|
|
/* It's a lot of work and synchronization to add a new ptrace |
|
* register for GDB to save and restore in order to get |
|
* orig_i0 correct for syscall restarts when debugging. |
|
* |
|
* Although it should be the case that most of the global |
|
* registers are volatile across a system call, glibc already |
|
* depends upon that fact that we preserve them. So we can't |
|
* just use any global register to save away the orig_i0 value. |
|
* |
|
* In particular %g2, %g3, %g4, and %g5 are all assumed to be |
|
* preserved across a system call trap by various pieces of |
|
* code in glibc. |
|
* |
|
* %g7 is used as the "thread register". %g6 is not used in |
|
* any fixed manner. %g6 is used as a scratch register and |
|
* a compiler temporary, but it's value is never used across |
|
* a system call. Therefore %g6 is usable for orig_i0 storage. |
|
*/ |
|
if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C)) |
|
regs->u_regs[UREG_G6] = orig_i0; |
|
|
|
has_handler = get_signal(&ksig); |
|
|
|
/* If the debugger messes with the program counter, it clears |
|
* the software "in syscall" bit, directing us to not perform |
|
* a syscall restart. |
|
*/ |
|
restart_syscall = 0; |
|
if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C)) { |
|
restart_syscall = 1; |
|
orig_i0 = regs->u_regs[UREG_G6]; |
|
} |
|
|
|
if (has_handler) { |
|
if (restart_syscall) |
|
syscall_restart(orig_i0, regs, &ksig.ka.sa); |
|
handle_signal(&ksig, regs); |
|
} else { |
|
if (restart_syscall) { |
|
switch (regs->u_regs[UREG_I0]) { |
|
case ERESTARTNOHAND: |
|
case ERESTARTSYS: |
|
case ERESTARTNOINTR: |
|
/* replay the system call when we are done */ |
|
regs->u_regs[UREG_I0] = orig_i0; |
|
regs->pc -= 4; |
|
regs->npc -= 4; |
|
pt_regs_clear_syscall(regs); |
|
fallthrough; |
|
case ERESTART_RESTARTBLOCK: |
|
regs->u_regs[UREG_G1] = __NR_restart_syscall; |
|
regs->pc -= 4; |
|
regs->npc -= 4; |
|
pt_regs_clear_syscall(regs); |
|
} |
|
} |
|
restore_saved_sigmask(); |
|
} |
|
} |
|
|
|
void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, |
|
unsigned long thread_info_flags) |
|
{ |
|
if (thread_info_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL)) |
|
do_signal(regs, orig_i0); |
|
if (thread_info_flags & _TIF_NOTIFY_RESUME) |
|
tracehook_notify_resume(regs); |
|
} |
|
|
|
asmlinkage int do_sys_sigstack(struct sigstack __user *ssptr, |
|
struct sigstack __user *ossptr, |
|
unsigned long sp) |
|
{ |
|
int ret = -EFAULT; |
|
|
|
/* First see if old state is wanted. */ |
|
if (ossptr) { |
|
if (put_user(current->sas_ss_sp + current->sas_ss_size, |
|
&ossptr->the_stack) || |
|
__put_user(on_sig_stack(sp), &ossptr->cur_status)) |
|
goto out; |
|
} |
|
|
|
/* Now see if we want to update the new state. */ |
|
if (ssptr) { |
|
char *ss_sp; |
|
|
|
if (get_user(ss_sp, &ssptr->the_stack)) |
|
goto out; |
|
/* If the current stack was set with sigaltstack, don't |
|
swap stacks while we are on it. */ |
|
ret = -EPERM; |
|
if (current->sas_ss_sp && on_sig_stack(sp)) |
|
goto out; |
|
|
|
/* Since we don't know the extent of the stack, and we don't |
|
track onstack-ness, but rather calculate it, we must |
|
presume a size. Ho hum this interface is lossy. */ |
|
current->sas_ss_sp = (unsigned long)ss_sp - SIGSTKSZ; |
|
current->sas_ss_size = SIGSTKSZ; |
|
} |
|
ret = 0; |
|
out: |
|
return ret; |
|
}
|
|
|