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| author |   Cyril Bur <cyrilbur@gmail.com> | 2016-09-23 16:18:12 +1000 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2016-10-04 16:43:07 +1100 |
| commit | d11994314b2bfe028bc39be24b44298787925160 (patch) | |
| tree | 09bf53fd6dfb5958d20f2cc2ab0849a8df17c911 /arch/powerpc/kernel/signal.h | |
| parent | powerpc: Never giveup a reclaimed thread when enabling kernel {fp, altivec, vsx} (diff) | |
| download | linux-dev-d11994314b2bfe028bc39be24b44298787925160.tar.xz linux-dev-d11994314b2bfe028bc39be24b44298787925160.zip | |
powerpc: signals: Stop using current in signal code
Much of the signal code takes a pt_regs on which it operates. Over
time the signal code has needed to know more about the thread than
what pt_regs can supply, this information is obtained as needed by
using 'current'.
This approach is not strictly incorrect however it does mean that
there is now a hard requirement that the pt_regs being passed around
does belong to current, this is never checked. A safer approach is for
the majority of the signal functions to take a task_struct from which
they can obtain pt_regs and any other information they need. The
caveat that the task_struct they are passed must be current doesn't go
away but can more easily be checked for.
Functions called from outside powerpc signal code are passed a pt_regs
and they can confirm that the pt_regs is that of current and pass
current to other functions, furthurmore, powerpc signal functions can
check that the task_struct they are passed is the same as current
avoiding possible corruption of current (or the task they are passed)
if this assertion ever fails.
CC: paulus@samba.org
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel/signal.h')
| -rw-r--r-- | arch/powerpc/kernel/signal.h | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/arch/powerpc/kernel/signal.h b/arch/powerpc/kernel/signal.h index be305c858e51..254ca074504f 100644 --- a/arch/powerpc/kernel/signal.h +++ b/arch/powerpc/kernel/signal.h @@ -16,10 +16,10 @@ extern void __user *get_sigframe(struct ksignal *ksig, unsigned long sp, size_t frame_size, int is_32); extern int handle_signal32(struct ksignal *ksig, sigset_t *oldset, - struct pt_regs *regs); + struct task_struct *tsk); extern int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset, - struct pt_regs *regs); + struct task_struct *tsk); extern unsigned long copy_fpr_to_user(void __user *to, struct task_struct *task); @@ -29,6 +29,8 @@ extern unsigned long copy_fpr_from_user(struct task_struct *task, void __user *from); extern unsigned long copy_transact_fpr_from_user(struct task_struct *task, void __user *from); +extern unsigned long get_tm_stackpointer(struct task_struct *tsk); + #ifdef CONFIG_VSX extern unsigned long copy_vsx_to_user(void __user *to, struct task_struct *task); @@ -43,12 +45,12 @@ extern unsigned long copy_transact_vsx_from_user(struct task_struct *task, #ifdef CONFIG_PPC64 extern int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, - struct pt_regs *regs); + struct task_struct *tsk); #else /* CONFIG_PPC64 */ static inline int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, - struct pt_regs *regs) + struct task_struct *tsk) { return -EFAULT; } |