a5f6096c80
Handle floating point state in across signals correctly. UML/i386 needs to know whether the host does PTRACE_[GS]ETFPXREGS, so an arch_init_registers hook is added, which on x86_64 does nothing. UML doesn't save and restore floating point registers on kernel entry and exit, so they need to be copied between the host process and the sigcontext. save_fpx_registers and restore_fpx_registers are added for this purpose. save_fp_registers and restore_fp_registers already exist. There was a bunch of floating point state conversion code in arch/um/sys-i386/ptrace.c which isn't needed there, but is needed in signal.c, so it is moved over. The i386 code now distinguishes between fp and fpx state and handles them correctly. The x86_64 code just needs to copy state as-is between the host process and the stack. There are also some fixes there to pass the correct address of the floating point state around. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
285 lines
7.9 KiB
C
285 lines
7.9 KiB
C
/*
|
|
* Copyright (C) 2003 PathScale, Inc.
|
|
* Licensed under the GPL
|
|
*/
|
|
|
|
#include "linux/personality.h"
|
|
#include "linux/ptrace.h"
|
|
#include "asm/unistd.h"
|
|
#include "asm/uaccess.h"
|
|
#include "asm/ucontext.h"
|
|
#include "frame_kern.h"
|
|
#include "skas.h"
|
|
|
|
void copy_sc(struct uml_pt_regs *regs, void *from)
|
|
{
|
|
struct sigcontext *sc = from;
|
|
|
|
#define GETREG(regs, regno, sc, regname) \
|
|
(regs)->gp[(regno) / sizeof(unsigned long)] = (sc)->regname
|
|
|
|
GETREG(regs, R8, sc, r8);
|
|
GETREG(regs, R9, sc, r9);
|
|
GETREG(regs, R10, sc, r10);
|
|
GETREG(regs, R11, sc, r11);
|
|
GETREG(regs, R12, sc, r12);
|
|
GETREG(regs, R13, sc, r13);
|
|
GETREG(regs, R14, sc, r14);
|
|
GETREG(regs, R15, sc, r15);
|
|
GETREG(regs, RDI, sc, rdi);
|
|
GETREG(regs, RSI, sc, rsi);
|
|
GETREG(regs, RBP, sc, rbp);
|
|
GETREG(regs, RBX, sc, rbx);
|
|
GETREG(regs, RDX, sc, rdx);
|
|
GETREG(regs, RAX, sc, rax);
|
|
GETREG(regs, RCX, sc, rcx);
|
|
GETREG(regs, RSP, sc, rsp);
|
|
GETREG(regs, RIP, sc, rip);
|
|
GETREG(regs, EFLAGS, sc, eflags);
|
|
GETREG(regs, CS, sc, cs);
|
|
|
|
#undef GETREG
|
|
}
|
|
|
|
static int copy_sc_from_user(struct pt_regs *regs,
|
|
struct sigcontext __user *from,
|
|
struct _fpstate __user *fpp)
|
|
{
|
|
struct user_i387_struct fp;
|
|
int err = 0;
|
|
|
|
#define GETREG(regs, regno, sc, regname) \
|
|
__get_user((regs)->regs.gp[(regno) / sizeof(unsigned long)], \
|
|
&(sc)->regname)
|
|
|
|
err |= GETREG(regs, R8, from, r8);
|
|
err |= GETREG(regs, R9, from, r9);
|
|
err |= GETREG(regs, R10, from, r10);
|
|
err |= GETREG(regs, R11, from, r11);
|
|
err |= GETREG(regs, R12, from, r12);
|
|
err |= GETREG(regs, R13, from, r13);
|
|
err |= GETREG(regs, R14, from, r14);
|
|
err |= GETREG(regs, R15, from, r15);
|
|
err |= GETREG(regs, RDI, from, rdi);
|
|
err |= GETREG(regs, RSI, from, rsi);
|
|
err |= GETREG(regs, RBP, from, rbp);
|
|
err |= GETREG(regs, RBX, from, rbx);
|
|
err |= GETREG(regs, RDX, from, rdx);
|
|
err |= GETREG(regs, RAX, from, rax);
|
|
err |= GETREG(regs, RCX, from, rcx);
|
|
err |= GETREG(regs, RSP, from, rsp);
|
|
err |= GETREG(regs, RIP, from, rip);
|
|
err |= GETREG(regs, EFLAGS, from, eflags);
|
|
err |= GETREG(regs, CS, from, cs);
|
|
if (err)
|
|
return 1;
|
|
|
|
#undef GETREG
|
|
|
|
err = copy_from_user(&fp, fpp, sizeof(struct user_i387_struct));
|
|
if (err)
|
|
return 1;
|
|
|
|
err = restore_fp_registers(userspace_pid[current_thread->cpu],
|
|
(unsigned long *) &fp);
|
|
if (err < 0) {
|
|
printk(KERN_ERR "copy_sc_from_user - "
|
|
"restore_fp_registers failed, errno = %d\n",
|
|
-err);
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int copy_sc_to_user(struct sigcontext __user *to,
|
|
struct _fpstate __user *to_fp, struct pt_regs *regs,
|
|
unsigned long mask, unsigned long sp)
|
|
{
|
|
struct faultinfo * fi = ¤t->thread.arch.faultinfo;
|
|
struct user_i387_struct fp;
|
|
int err = 0;
|
|
|
|
err |= __put_user(0, &to->gs);
|
|
err |= __put_user(0, &to->fs);
|
|
|
|
#define PUTREG(regs, regno, sc, regname) \
|
|
__put_user((regs)->regs.gp[(regno) / sizeof(unsigned long)], \
|
|
&(sc)->regname)
|
|
|
|
err |= PUTREG(regs, RDI, to, rdi);
|
|
err |= PUTREG(regs, RSI, to, rsi);
|
|
err |= PUTREG(regs, RBP, to, rbp);
|
|
/* Must use orignal RSP, which is passed in, rather than what's in
|
|
* the pt_regs, because that's already been updated to point at the
|
|
* signal frame.
|
|
*/
|
|
err |= __put_user(sp, &to->rsp);
|
|
err |= PUTREG(regs, RBX, to, rbx);
|
|
err |= PUTREG(regs, RDX, to, rdx);
|
|
err |= PUTREG(regs, RCX, to, rcx);
|
|
err |= PUTREG(regs, RAX, to, rax);
|
|
err |= PUTREG(regs, R8, to, r8);
|
|
err |= PUTREG(regs, R9, to, r9);
|
|
err |= PUTREG(regs, R10, to, r10);
|
|
err |= PUTREG(regs, R11, to, r11);
|
|
err |= PUTREG(regs, R12, to, r12);
|
|
err |= PUTREG(regs, R13, to, r13);
|
|
err |= PUTREG(regs, R14, to, r14);
|
|
err |= PUTREG(regs, R15, to, r15);
|
|
err |= PUTREG(regs, CS, to, cs); /* XXX x86_64 doesn't do this */
|
|
|
|
err |= __put_user(fi->cr2, &to->cr2);
|
|
err |= __put_user(fi->error_code, &to->err);
|
|
err |= __put_user(fi->trap_no, &to->trapno);
|
|
|
|
err |= PUTREG(regs, RIP, to, rip);
|
|
err |= PUTREG(regs, EFLAGS, to, eflags);
|
|
#undef PUTREG
|
|
|
|
err |= __put_user(mask, &to->oldmask);
|
|
if (err)
|
|
return 1;
|
|
|
|
err = save_fp_registers(userspace_pid[current_thread->cpu],
|
|
(unsigned long *) &fp);
|
|
if (err < 0) {
|
|
printk(KERN_ERR "copy_sc_from_user - restore_fp_registers "
|
|
"failed, errno = %d\n", -err);
|
|
return 1;
|
|
}
|
|
|
|
if (copy_to_user(to_fp, &fp, sizeof(struct user_i387_struct)))
|
|
return 1;
|
|
|
|
return(err);
|
|
}
|
|
|
|
struct rt_sigframe
|
|
{
|
|
char __user *pretcode;
|
|
struct ucontext uc;
|
|
struct siginfo info;
|
|
struct _fpstate fpstate;
|
|
};
|
|
|
|
#define round_down(m, n) (((m) / (n)) * (n))
|
|
|
|
int setup_signal_stack_si(unsigned long stack_top, int sig,
|
|
struct k_sigaction *ka, struct pt_regs * regs,
|
|
siginfo_t *info, sigset_t *set)
|
|
{
|
|
struct rt_sigframe __user *frame;
|
|
unsigned long save_sp = PT_REGS_RSP(regs);
|
|
int err = 0;
|
|
struct task_struct *me = current;
|
|
|
|
frame = (struct rt_sigframe __user *)
|
|
round_down(stack_top - sizeof(struct rt_sigframe), 16);
|
|
/* Subtract 128 for a red zone and 8 for proper alignment */
|
|
frame = (struct rt_sigframe __user *) ((unsigned long) frame - 128 - 8);
|
|
|
|
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
|
|
goto out;
|
|
|
|
if (ka->sa.sa_flags & SA_SIGINFO) {
|
|
err |= copy_siginfo_to_user(&frame->info, info);
|
|
if (err)
|
|
goto out;
|
|
}
|
|
|
|
/* Update SP now because the page fault handler refuses to extend
|
|
* the stack if the faulting address is too far below the current
|
|
* SP, which frame now certainly is. If there's an error, the original
|
|
* value is restored on the way out.
|
|
* When writing the sigcontext to the stack, we have to write the
|
|
* original value, so that's passed to copy_sc_to_user, which does
|
|
* the right thing with it.
|
|
*/
|
|
PT_REGS_RSP(regs) = (unsigned long) frame;
|
|
|
|
/* Create the ucontext. */
|
|
err |= __put_user(0, &frame->uc.uc_flags);
|
|
err |= __put_user(0, &frame->uc.uc_link);
|
|
err |= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
|
|
err |= __put_user(sas_ss_flags(save_sp),
|
|
&frame->uc.uc_stack.ss_flags);
|
|
err |= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
|
|
err |= copy_sc_to_user(&frame->uc.uc_mcontext, &frame->fpstate, regs,
|
|
set->sig[0], save_sp);
|
|
err |= __put_user(&frame->fpstate, &frame->uc.uc_mcontext.fpstate);
|
|
if (sizeof(*set) == 16) {
|
|
__put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
|
|
__put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]);
|
|
}
|
|
else
|
|
err |= __copy_to_user(&frame->uc.uc_sigmask, set,
|
|
sizeof(*set));
|
|
|
|
/* Set up to return from userspace. If provided, use a stub
|
|
already in userspace. */
|
|
/* x86-64 should always use SA_RESTORER. */
|
|
if (ka->sa.sa_flags & SA_RESTORER)
|
|
err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
|
|
else
|
|
/* could use a vstub here */
|
|
goto restore_sp;
|
|
|
|
if (err)
|
|
goto restore_sp;
|
|
|
|
/* Set up registers for signal handler */
|
|
{
|
|
struct exec_domain *ed = current_thread_info()->exec_domain;
|
|
if (unlikely(ed && ed->signal_invmap && sig < 32))
|
|
sig = ed->signal_invmap[sig];
|
|
}
|
|
|
|
PT_REGS_RDI(regs) = sig;
|
|
/* In case the signal handler was declared without prototypes */
|
|
PT_REGS_RAX(regs) = 0;
|
|
|
|
/* This also works for non SA_SIGINFO handlers because they expect the
|
|
next argument after the signal number on the stack. */
|
|
PT_REGS_RSI(regs) = (unsigned long) &frame->info;
|
|
PT_REGS_RDX(regs) = (unsigned long) &frame->uc;
|
|
PT_REGS_RIP(regs) = (unsigned long) ka->sa.sa_handler;
|
|
out:
|
|
return err;
|
|
|
|
restore_sp:
|
|
PT_REGS_RSP(regs) = save_sp;
|
|
return err;
|
|
}
|
|
|
|
long sys_rt_sigreturn(struct pt_regs *regs)
|
|
{
|
|
unsigned long sp = PT_REGS_SP(¤t->thread.regs);
|
|
struct rt_sigframe __user *frame =
|
|
(struct rt_sigframe __user *)(sp - 8);
|
|
struct ucontext __user *uc = &frame->uc;
|
|
sigset_t set;
|
|
|
|
if (copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
|
|
goto segfault;
|
|
|
|
sigdelsetmask(&set, ~_BLOCKABLE);
|
|
|
|
spin_lock_irq(¤t->sighand->siglock);
|
|
current->blocked = set;
|
|
recalc_sigpending();
|
|
spin_unlock_irq(¤t->sighand->siglock);
|
|
|
|
if (copy_sc_from_user(¤t->thread.regs, &uc->uc_mcontext,
|
|
&frame->fpstate))
|
|
goto segfault;
|
|
|
|
/* Avoid ERESTART handling */
|
|
PT_REGS_SYSCALL_NR(¤t->thread.regs) = -1;
|
|
return(PT_REGS_SYSCALL_RET(¤t->thread.regs));
|
|
|
|
segfault:
|
|
force_sig(SIGSEGV, current);
|
|
return 0;
|
|
}
|