/*
* Do a signal return; undo the signal stack.
*/
int sys_sigreturn(int r3, int r4, int r5, int r6, int r7, int r8,
struct pt_regs *regs)
{
struct sigcontext __user *sc;
struct sigcontext sigctx;
struct mcontext __user *sr;
sigset_t set;
/* Always make any pending restarted system calls return -EINTR */
current_thread_info()->restart_block.fn = do_no_restart_syscall;
sc = (struct sigcontext __user *)(regs->gpr[1] + __SIGNAL_FRAMESIZE);
if (copy_from_user(&sigctx, sc, sizeof(sigctx)))
goto badframe;
set.sig[0] = sigctx.oldmask;
set.sig[1] = sigctx._unused[3];
restore_sigmask(&set);
sr = (struct mcontext __user *) sigctx.regs;
if (verify_area(VERIFY_READ, sr, sizeof(*sr))
|| restore_user_regs(regs, sr, 1))
goto badframe;
sigreturn_exit(regs); /* doesn't return */
return 0;
badframe:
force_sig(SIGSEGV, current);
return 0;
}
int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
unsigned long r6, unsigned long r7, unsigned long r8,
struct pt_regs *regs)
{
struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1];
sigset_t set;
/* Always make any pending restarted system calls return -EINTR */
current_thread_info()->restart_block.fn = do_no_restart_syscall;
if (!access_ok(VERIFY_READ, uc, sizeof(*uc)))
goto badframe;
if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
goto badframe;
restore_sigmask(&set);
if (restore_sigcontext(regs, NULL, 1, &uc->uc_mcontext))
goto badframe;
/* do_sigaltstack expects a __user pointer and won't modify
* what's in there anyway
*/
do_sigaltstack(&uc->uc_stack, NULL, regs->gpr[1]);
set_thread_flag(TIF_RESTOREALL);
return 0;
badframe:
#if DEBUG_SIG
printk("badframe in sys_rt_sigreturn, regs=%p uc=%p &uc->uc_mcontext=%p\n",
regs, uc, &uc->uc_mcontext);
#endif
force_sig(SIGSEGV, current);
return 0;
}
pid_t launch_child(int flags, child_options *chldopts, int (*fn)(void *), void *arg) {
pid_t ret;
if(chldopts->daemonize) {
ret = fork();
switch(ret) {
case 0:
/* Do some cleanup in the child */
close_fd(&(chldopts->sfd));
restore_sigmask(&(chldopts->old_sigmask));
/* Become a session leader */
if( setsid() == -1 )
errExit("setsid");
/* In the child, go on */
break;
default:
/* Parent, drop all capabilities from the permitted capability set */
drop_caps_forever();
return ret;
}
}
need_cap(CAP_SYS_ADMIN);
ret = clone1(flags);
switch(ret) {
case 0:
/* Drop all capabilities from the effective capability set */
drop_caps();
/* Do some cleanup in the child */
close_fd(&(chldopts->sfd));
restore_sigmask(&(chldopts->old_sigmask));
/* Call the function */
fn(arg);
/* The last call should not have returned */
exit(EXIT_FAILURE);
default:
if(chldopts->daemonize)
/* Parent, we exit right away */
exit(EXIT_SUCCESS);
else {
/* Parent, drop all capabilities from the permitted capability set */
drop_caps_forever();
return ret;
}
}
}
static int do_setcontext(struct ucontext __user *ucp, struct pt_regs *regs, int sig)
{
sigset_t set;
struct mcontext __user *mcp;
if (__copy_from_user(&set, &ucp->uc_sigmask, sizeof(set))
|| __get_user(mcp, &ucp->uc_regs))
return -EFAULT;
restore_sigmask(&set);
if (restore_user_regs(regs, mcp, sig))
return -EFAULT;
return 0;
}
/*
* Handle {get,set,swap}_context operations
*/
int sys_swapcontext(struct ucontext __user *old_ctx,
struct ucontext __user *new_ctx,
long ctx_size, long r6, long r7, long r8, struct pt_regs *regs)
{
unsigned char tmp;
sigset_t set;
/* Context size is for future use. Right now, we only make sure
* we are passed something we understand
*/
if (ctx_size < sizeof(struct ucontext))
return -EINVAL;
if (old_ctx != NULL) {
if (!access_ok(VERIFY_WRITE, old_ctx, sizeof(*old_ctx))
|| setup_sigcontext(&old_ctx->uc_mcontext, regs, 0, NULL, 0)
|| __copy_to_user(&old_ctx->uc_sigmask,
¤t->blocked, sizeof(sigset_t)))
return -EFAULT;
}
if (new_ctx == NULL)
return 0;
if (!access_ok(VERIFY_READ, new_ctx, sizeof(*new_ctx))
|| __get_user(tmp, (u8 __user *) new_ctx)
|| __get_user(tmp, (u8 __user *) (new_ctx + 1) - 1))
return -EFAULT;
/*
* If we get a fault copying the context into the kernel's
* image of the user's registers, we can't just return -EFAULT
* because the user's registers will be corrupted. For instance
* the NIP value may have been updated but not some of the
* other registers. Given that we have done the access_ok
* and successfully read the first and last bytes of the region
* above, this should only happen in an out-of-memory situation
* or if another thread unmaps the region containing the context.
* We kill the task with a SIGSEGV in this situation.
*/
if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set)))
do_exit(SIGSEGV);
restore_sigmask(&set);
if (restore_sigcontext(regs, NULL, 0, &new_ctx->uc_mcontext))
do_exit(SIGSEGV);
/* This returns like rt_sigreturn */
set_thread_flag(TIF_RESTOREALL);
return 0;
}
int sys_swapcontext(struct ucontext __user *old_ctx,
struct ucontext __user *new_ctx,
long ctx_size, long r6, long r7, long r8, struct pt_regs *regs)
{
unsigned char tmp;
sigset_t set;
unsigned long new_msr = 0;
int ctx_has_vsx_region = 0;
if (new_ctx &&
get_user(new_msr, &new_ctx->uc_mcontext.gp_regs[PT_MSR]))
return -EFAULT;
if (ctx_size < UCONTEXTSIZEWITHOUTVSX)
return -EINVAL;
if ((ctx_size < sizeof(struct ucontext)) &&
(new_msr & MSR_VSX))
return -EINVAL;
if (ctx_size >= sizeof(struct ucontext))
ctx_has_vsx_region = 1;
if (old_ctx != NULL) {
if (!access_ok(VERIFY_WRITE, old_ctx, ctx_size)
|| setup_sigcontext(&old_ctx->uc_mcontext, regs, 0, NULL, 0,
ctx_has_vsx_region)
|| __copy_to_user(&old_ctx->uc_sigmask,
¤t->blocked, sizeof(sigset_t)))
return -EFAULT;
}
if (new_ctx == NULL)
return 0;
if (!access_ok(VERIFY_READ, new_ctx, ctx_size)
|| __get_user(tmp, (u8 __user *) new_ctx)
|| __get_user(tmp, (u8 __user *) new_ctx + ctx_size - 1))
return -EFAULT;
if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set)))
do_exit(SIGSEGV);
restore_sigmask(&set);
if (restore_sigcontext(regs, NULL, 0, &new_ctx->uc_mcontext))
do_exit(SIGSEGV);
set_thread_flag(TIF_RESTOREALL);
return 0;
}
int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
unsigned long r6, unsigned long r7, unsigned long r8,
struct pt_regs *regs)
{
struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1];
sigset_t set;
current_thread_info()->restart_block.fn = do_no_restart_syscall;
if (!access_ok(VERIFY_READ, uc, sizeof(*uc)))
goto badframe;
if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
goto badframe;
restore_sigmask(&set);
if (restore_sigcontext(regs, NULL, 1, &uc->uc_mcontext))
goto badframe;
do_sigaltstack(&uc->uc_stack, NULL, regs->gpr[1]);
set_thread_flag(TIF_RESTOREALL);
return 0;
badframe:
#if DEBUG_SIG
printk("badframe in sys_rt_sigreturn, regs=%p uc=%p &uc->uc_mcontext=%p\n",
regs, uc, &uc->uc_mcontext);
#endif
if (show_unhandled_signals)
printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
current->comm, current->pid, "rt_sigreturn",
(long)uc, regs->nip, regs->link);
force_sig(SIGSEGV, current);
return 0;
}
/*
* Handle {get,set,swap}_context operations
*/
int sys_swapcontext(struct ucontext __user *old_ctx,
struct ucontext __user *new_ctx,
long ctx_size, long r6, long r7, long r8, struct pt_regs *regs)
{
unsigned char tmp;
sigset_t set;
unsigned long new_msr = 0;
int ctx_has_vsx_region = 0;
if (new_ctx &&
get_user(new_msr, &new_ctx->uc_mcontext.gp_regs[PT_MSR]))
return -EFAULT;
/*
* Check that the context is not smaller than the original
* size (with VMX but without VSX)
*/
if (ctx_size < UCONTEXTSIZEWITHOUTVSX)
return -EINVAL;
/*
* If the new context state sets the MSR VSX bits but
* it doesn't provide VSX state.
*/
if ((ctx_size < sizeof(struct ucontext)) &&
(new_msr & MSR_VSX))
return -EINVAL;
/* Does the context have enough room to store VSX data? */
if (ctx_size >= sizeof(struct ucontext))
ctx_has_vsx_region = 1;
if (old_ctx != NULL) {
if (!access_ok(VERIFY_WRITE, old_ctx, ctx_size)
|| setup_sigcontext(&old_ctx->uc_mcontext, regs, 0, NULL, 0,
ctx_has_vsx_region)
|| __copy_to_user(&old_ctx->uc_sigmask,
¤t->blocked, sizeof(sigset_t)))
return -EFAULT;
}
if (new_ctx == NULL)
return 0;
if (!access_ok(VERIFY_READ, new_ctx, ctx_size)
|| __get_user(tmp, (u8 __user *) new_ctx)
|| __get_user(tmp, (u8 __user *) new_ctx + ctx_size - 1))
return -EFAULT;
/*
* If we get a fault copying the context into the kernel's
* image of the user's registers, we can't just return -EFAULT
* because the user's registers will be corrupted. For instance
* the NIP value may have been updated but not some of the
* other registers. Given that we have done the access_ok
* and successfully read the first and last bytes of the region
* above, this should only happen in an out-of-memory situation
* or if another thread unmaps the region containing the context.
* We kill the task with a SIGSEGV in this situation.
*/
if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set)))
do_exit(SIGSEGV);
restore_sigmask(&set);
if (restore_sigcontext(regs, NULL, 0, &new_ctx->uc_mcontext))
do_exit(SIGSEGV);
/* This returns like rt_sigreturn */
set_thread_flag(TIF_RESTOREALL);
return 0;
}
