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author | Jeff Dike <jdike@addtoit.com> | 2007-10-16 01:27:15 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-16 09:43:07 -0700 |
commit | a5f6096c805e6d2fa03ee932f8c70af34cee41a0 (patch) | |
tree | c74d984c0e2fc2958425df65605dd3451adc6520 /arch/um/sys-x86_64/signal.c | |
parent | 189872f968def833727b6bfef83ebd7440c538e6 (diff) | |
download | kernel_samsung_smdk4412-a5f6096c805e6d2fa03ee932f8c70af34cee41a0.zip kernel_samsung_smdk4412-a5f6096c805e6d2fa03ee932f8c70af34cee41a0.tar.gz kernel_samsung_smdk4412-a5f6096c805e6d2fa03ee932f8c70af34cee41a0.tar.bz2 |
uml: floating point signal delivery fixes
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>
Diffstat (limited to 'arch/um/sys-x86_64/signal.c')
-rw-r--r-- | arch/um/sys-x86_64/signal.c | 53 |
1 files changed, 39 insertions, 14 deletions
diff --git a/arch/um/sys-x86_64/signal.c b/arch/um/sys-x86_64/signal.c index c98dd7f..a8e5fd7 100644 --- a/arch/um/sys-x86_64/signal.c +++ b/arch/um/sys-x86_64/signal.c @@ -42,8 +42,10 @@ void copy_sc(struct uml_pt_regs *regs, void *from) } static int copy_sc_from_user(struct pt_regs *regs, - struct sigcontext __user *from) + struct sigcontext __user *from, + struct _fpstate __user *fpp) { + struct user_i387_struct fp; int err = 0; #define GETREG(regs, regno, sc, regname) \ @@ -69,10 +71,25 @@ static int copy_sc_from_user(struct pt_regs *regs, err |= GETREG(regs, RIP, from, rip); err |= GETREG(regs, EFLAGS, from, eflags); err |= GETREG(regs, CS, from, cs); + if (err) + return 1; #undef GETREG - return err; + 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, @@ -80,6 +97,7 @@ static int copy_sc_to_user(struct sigcontext __user *to, 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); @@ -120,6 +138,19 @@ static int copy_sc_to_user(struct sigcontext __user *to, #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); } @@ -129,6 +160,7 @@ struct rt_sigframe char __user *pretcode; struct ucontext uc; struct siginfo info; + struct _fpstate fpstate; }; #define round_down(m, n) (((m) / (n)) * (n)) @@ -138,7 +170,6 @@ int setup_signal_stack_si(unsigned long stack_top, int sig, siginfo_t *info, sigset_t *set) { struct rt_sigframe __user *frame; - struct _fpstate __user *fp = NULL; unsigned long save_sp = PT_REGS_RSP(regs); int err = 0; struct task_struct *me = current; @@ -148,13 +179,6 @@ int setup_signal_stack_si(unsigned long stack_top, int sig, /* 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, fp, sizeof(struct _fpstate))) - goto out; - -#if 0 /* XXX */ - if (save_i387(fp) < 0) - err |= -1; -#endif if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) goto out; @@ -181,9 +205,9 @@ int setup_signal_stack_si(unsigned long stack_top, int sig, 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, fp, regs, set->sig[0], - save_sp); - err |= __put_user(fp, &frame->uc.uc_mcontext.fpstate); + 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]); @@ -246,7 +270,8 @@ long sys_rt_sigreturn(struct pt_regs *regs) recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); - if (copy_sc_from_user(¤t->thread.regs, &uc->uc_mcontext)) + if (copy_sc_from_user(¤t->thread.regs, &uc->uc_mcontext, + &frame->fpstate)) goto segfault; /* Avoid ERESTART handling */ |