[PATCH v3 06/21] powerpc: signals: Stop using current in signal code
Cyril Bur
cyrilbur at gmail.com
Wed Aug 17 13:43:08 AEST 2016
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 at samba.org
Signed-off-by: Cyril Bur <cyrilbur at gmail.com>
---
arch/powerpc/include/asm/signal.h | 2 -
arch/powerpc/kernel/signal.c | 41 ++++----
arch/powerpc/kernel/signal.h | 10 +-
arch/powerpc/kernel/signal_32.c | 31 +++---
arch/powerpc/kernel/signal_64.c | 192 +++++++++++++++++++++-----------------
5 files changed, 154 insertions(+), 122 deletions(-)
diff --git a/arch/powerpc/include/asm/signal.h b/arch/powerpc/include/asm/signal.h
index 9322c28..5ff7772 100644
--- a/arch/powerpc/include/asm/signal.h
+++ b/arch/powerpc/include/asm/signal.h
@@ -5,6 +5,4 @@
#include <uapi/asm/signal.h>
#include <uapi/asm/ptrace.h>
-extern unsigned long get_tm_stackpointer(struct pt_regs *regs);
-
#endif /* _ASM_POWERPC_SIGNAL_H */
diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index cb64d6f..bbe77ae 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -99,22 +99,24 @@ static void check_syscall_restart(struct pt_regs *regs, struct k_sigaction *ka,
}
}
-static void do_signal(struct pt_regs *regs)
+static void do_signal(struct task_struct *tsk)
{
sigset_t *oldset = sigmask_to_save();
struct ksignal ksig;
int ret;
int is32 = is_32bit_task();
+ BUG_ON(tsk != current);
+
get_signal(&ksig);
/* Is there any syscall restart business here ? */
- check_syscall_restart(regs, &ksig.ka, ksig.sig > 0);
+ check_syscall_restart(tsk->thread.regs, &ksig.ka, ksig.sig > 0);
if (ksig.sig <= 0) {
/* No signal to deliver -- put the saved sigmask back */
restore_saved_sigmask();
- regs->trap = 0;
+ tsk->thread.regs->trap = 0;
return; /* no signals delivered */
}
@@ -124,23 +126,22 @@ static void do_signal(struct pt_regs *regs)
* user space. The DABR will have been cleared if it
* triggered inside the kernel.
*/
- if (current->thread.hw_brk.address &&
- current->thread.hw_brk.type)
- __set_breakpoint(¤t->thread.hw_brk);
+ if (tsk->thread.hw_brk.address && tsk->thread.hw_brk.type)
+ __set_breakpoint(&tsk->thread.hw_brk);
#endif
/* Re-enable the breakpoints for the signal stack */
- thread_change_pc(current, regs);
+ thread_change_pc(tsk, tsk->thread.regs);
if (is32) {
if (ksig.ka.sa.sa_flags & SA_SIGINFO)
- ret = handle_rt_signal32(&ksig, oldset, regs);
+ ret = handle_rt_signal32(&ksig, oldset, tsk);
else
- ret = handle_signal32(&ksig, oldset, regs);
+ ret = handle_signal32(&ksig, oldset, tsk);
} else {
- ret = handle_rt_signal64(&ksig, oldset, regs);
+ ret = handle_rt_signal64(&ksig, oldset, tsk);
}
- regs->trap = 0;
+ tsk->thread.regs->trap = 0;
signal_setup_done(ret, &ksig, test_thread_flag(TIF_SINGLESTEP));
}
@@ -151,8 +152,10 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
if (thread_info_flags & _TIF_UPROBE)
uprobe_notify_resume(regs);
- if (thread_info_flags & _TIF_SIGPENDING)
- do_signal(regs);
+ if (thread_info_flags & _TIF_SIGPENDING) {
+ BUG_ON(regs != current->thread.regs);
+ do_signal(current);
+ }
if (thread_info_flags & _TIF_NOTIFY_RESUME) {
clear_thread_flag(TIF_NOTIFY_RESUME);
@@ -162,7 +165,7 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
user_enter();
}
-unsigned long get_tm_stackpointer(struct pt_regs *regs)
+unsigned long get_tm_stackpointer(struct task_struct *tsk)
{
/* When in an active transaction that takes a signal, we need to be
* careful with the stack. It's possible that the stack has moved back
@@ -187,11 +190,13 @@ unsigned long get_tm_stackpointer(struct pt_regs *regs)
*/
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
- if (MSR_TM_ACTIVE(regs->msr)) {
+ BUG_ON(tsk != current);
+
+ if (MSR_TM_ACTIVE(tsk->thread.regs->msr)) {
tm_reclaim_current(TM_CAUSE_SIGNAL);
- if (MSR_TM_TRANSACTIONAL(regs->msr))
- return current->thread.ckpt_regs.gpr[1];
+ if (MSR_TM_TRANSACTIONAL(tsk->thread.regs->msr))
+ return tsk->thread.ckpt_regs.gpr[1];
}
#endif
- return regs->gpr[1];
+ return tsk->thread.regs->gpr[1];
}
diff --git a/arch/powerpc/kernel/signal.h b/arch/powerpc/kernel/signal.h
index be305c8..254ca07 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;
}
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index b6aa378..d11cc9d 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -971,7 +971,7 @@ int copy_siginfo_from_user32(siginfo_t *to, struct compat_siginfo __user *from)
* (one which gets siginfo).
*/
int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
- struct pt_regs *regs)
+ struct task_struct *tsk)
{
struct rt_sigframe __user *rt_sf;
struct mcontext __user *frame;
@@ -980,10 +980,13 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
unsigned long newsp = 0;
int sigret;
unsigned long tramp;
+ struct pt_regs *regs = tsk->thread.regs;
+
+ BUG_ON(tsk != current);
/* Set up Signal Frame */
/* Put a Real Time Context onto stack */
- rt_sf = get_sigframe(ksig, get_tm_stackpointer(regs), sizeof(*rt_sf), 1);
+ rt_sf = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*rt_sf), 1);
addr = rt_sf;
if (unlikely(rt_sf == NULL))
goto badframe;
@@ -1000,9 +1003,9 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
/* Save user registers on the stack */
frame = &rt_sf->uc.uc_mcontext;
addr = frame;
- if (vdso32_rt_sigtramp && current->mm->context.vdso_base) {
+ if (vdso32_rt_sigtramp && tsk->mm->context.vdso_base) {
sigret = 0;
- tramp = current->mm->context.vdso_base + vdso32_rt_sigtramp;
+ tramp = tsk->mm->context.vdso_base + vdso32_rt_sigtramp;
} else {
sigret = __NR_rt_sigreturn;
tramp = (unsigned long) frame->tramp;
@@ -1029,7 +1032,7 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
}
regs->link = tramp;
- current->thread.fp_state.fpscr = 0; /* turn off all fp exceptions */
+ tsk->thread.fp_state.fpscr = 0; /* turn off all fp exceptions */
/* create a stack frame for the caller of the handler */
newsp = ((unsigned long)rt_sf) - (__SIGNAL_FRAMESIZE + 16);
@@ -1054,7 +1057,7 @@ badframe:
printk_ratelimited(KERN_INFO
"%s[%d]: bad frame in handle_rt_signal32: "
"%p nip %08lx lr %08lx\n",
- current->comm, current->pid,
+ tsk->comm, tsk->pid,
addr, regs->nip, regs->link);
return 1;
@@ -1396,7 +1399,8 @@ int sys_debug_setcontext(struct ucontext __user *ctx,
/*
* OK, we're invoking a handler
*/
-int handle_signal32(struct ksignal *ksig, sigset_t *oldset, struct pt_regs *regs)
+int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
+ struct task_struct *tsk)
{
struct sigcontext __user *sc;
struct sigframe __user *frame;
@@ -1404,9 +1408,12 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset, struct pt_regs *regs
unsigned long newsp = 0;
int sigret;
unsigned long tramp;
+ struct pt_regs *regs = tsk->thread.regs;
+
+ BUG_ON(tsk != current);
/* Set up Signal Frame */
- frame = get_sigframe(ksig, get_tm_stackpointer(regs), sizeof(*frame), 1);
+ frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 1);
if (unlikely(frame == NULL))
goto badframe;
sc = (struct sigcontext __user *) &frame->sctx;
@@ -1425,9 +1432,9 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset, struct pt_regs *regs
|| __put_user(ksig->sig, &sc->signal))
goto badframe;
- if (vdso32_sigtramp && current->mm->context.vdso_base) {
+ if (vdso32_sigtramp && tsk->mm->context.vdso_base) {
sigret = 0;
- tramp = current->mm->context.vdso_base + vdso32_sigtramp;
+ tramp = tsk->mm->context.vdso_base + vdso32_sigtramp;
} else {
sigret = __NR_sigreturn;
tramp = (unsigned long) frame->mctx.tramp;
@@ -1449,7 +1456,7 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset, struct pt_regs *regs
regs->link = tramp;
- current->thread.fp_state.fpscr = 0; /* turn off all fp exceptions */
+ tsk->thread.fp_state.fpscr = 0; /* turn off all fp exceptions */
/* create a stack frame for the caller of the handler */
newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
@@ -1469,7 +1476,7 @@ badframe:
printk_ratelimited(KERN_INFO
"%s[%d]: bad frame in handle_signal32: "
"%p nip %08lx lr %08lx\n",
- current->comm, current->pid,
+ tsk->comm, tsk->pid,
frame, regs->nip, regs->link);
return 1;
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index 7e49984..6c1f99b 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -90,9 +90,9 @@ static elf_vrreg_t __user *sigcontext_vmx_regs(struct sigcontext __user *sc)
* Set up the sigcontext for the signal frame.
*/
-static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
- int signr, sigset_t *set, unsigned long handler,
- int ctx_has_vsx_region)
+static long setup_sigcontext(struct sigcontext __user *sc,
+ struct task_struct *tsk, int signr, sigset_t *set,
+ unsigned long handler, int ctx_has_vsx_region)
{
/* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
* process never used altivec yet (MSR_VEC is zero in pt_regs of
@@ -106,17 +106,20 @@ static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc);
unsigned long vrsave;
#endif
+ struct pt_regs *regs = tsk->thread.regs;
unsigned long msr = regs->msr;
long err = 0;
+ BUG_ON(tsk != current);
+
#ifdef CONFIG_ALTIVEC
err |= __put_user(v_regs, &sc->v_regs);
/* save altivec registers */
- if (current->thread.used_vr) {
- flush_altivec_to_thread(current);
+ if (tsk->thread.used_vr) {
+ flush_altivec_to_thread(tsk);
/* Copy 33 vec registers (vr0..31 and vscr) to the stack */
- err |= __copy_to_user(v_regs, ¤t->thread.vr_state,
+ err |= __copy_to_user(v_regs, &tsk->thread.vr_state,
33 * sizeof(vector128));
/* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg)
* contains valid data.
@@ -129,16 +132,16 @@ static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
vrsave = 0;
if (cpu_has_feature(CPU_FTR_ALTIVEC)) {
vrsave = mfspr(SPRN_VRSAVE);
- current->thread.vrsave = vrsave;
+ tsk->thread.vrsave = vrsave;
}
err |= __put_user(vrsave, (u32 __user *)&v_regs[33]);
#else /* CONFIG_ALTIVEC */
err |= __put_user(0, &sc->v_regs);
#endif /* CONFIG_ALTIVEC */
- flush_fp_to_thread(current);
+ flush_fp_to_thread(tsk);
/* copy fpr regs and fpscr */
- err |= copy_fpr_to_user(&sc->fp_regs, current);
+ err |= copy_fpr_to_user(&sc->fp_regs, tsk);
/*
* Clear the MSR VSX bit to indicate there is no valid state attached
@@ -151,10 +154,10 @@ static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
* then out to userspace. Update v_regs to point after the
* VMX data.
*/
- if (current->thread.used_vsr && ctx_has_vsx_region) {
- flush_vsx_to_thread(current);
+ if (tsk->thread.used_vsr && ctx_has_vsx_region) {
+ flush_vsx_to_thread(tsk);
v_regs += ELF_NVRREG;
- err |= copy_vsx_to_user(v_regs, current);
+ err |= copy_vsx_to_user(v_regs, tsk);
/* set MSR_VSX in the MSR value in the frame to
* indicate that sc->vs_reg) contains valid data.
*/
@@ -187,7 +190,7 @@ static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
*/
static long setup_tm_sigcontexts(struct sigcontext __user *sc,
struct sigcontext __user *tm_sc,
- struct pt_regs *regs,
+ struct task_struct *tsk,
int signr, sigset_t *set, unsigned long handler)
{
/* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
@@ -202,9 +205,12 @@ static long setup_tm_sigcontexts(struct sigcontext __user *sc,
elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc);
elf_vrreg_t __user *tm_v_regs = sigcontext_vmx_regs(tm_sc);
#endif
- unsigned long msr = regs->msr;
+ struct pt_regs *regs = tsk->thread.regs;
+ unsigned long msr = tsk->thread.ckpt_regs.msr;
long err = 0;
+ BUG_ON(tsk != current);
+
BUG_ON(!MSR_TM_ACTIVE(regs->msr));
/* Remove TM bits from thread's MSR. The MSR in the sigcontext
@@ -214,28 +220,28 @@ static long setup_tm_sigcontexts(struct sigcontext __user *sc,
*/
regs->msr &= ~MSR_TS_MASK;
- flush_fp_to_thread(current);
+ flush_fp_to_thread(tsk);
#ifdef CONFIG_ALTIVEC
err |= __put_user(v_regs, &sc->v_regs);
err |= __put_user(tm_v_regs, &tm_sc->v_regs);
/* save altivec registers */
- if (current->thread.used_vr) {
- flush_altivec_to_thread(current);
+ if (tsk->thread.used_vr) {
+ flush_altivec_to_thread(tsk);
/* Copy 33 vec registers (vr0..31 and vscr) to the stack */
- err |= __copy_to_user(v_regs, ¤t->thread.vr_state,
+ err |= __copy_to_user(v_regs, &tsk->thread.vr_state,
33 * sizeof(vector128));
/* If VEC was enabled there are transactional VRs valid too,
* else they're a copy of the checkpointed VRs.
*/
if (msr & MSR_VEC)
err |= __copy_to_user(tm_v_regs,
- ¤t->thread.transact_vr,
+ &tsk->thread.transact_vr,
33 * sizeof(vector128));
else
err |= __copy_to_user(tm_v_regs,
- ¤t->thread.vr_state,
+ &tsk->thread.vr_state,
33 * sizeof(vector128));
/* set MSR_VEC in the MSR value in the frame to indicate
@@ -247,13 +253,13 @@ static long setup_tm_sigcontexts(struct sigcontext __user *sc,
* use altivec.
*/
if (cpu_has_feature(CPU_FTR_ALTIVEC))
- current->thread.vrsave = mfspr(SPRN_VRSAVE);
- err |= __put_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
+ tsk->thread.vrsave = mfspr(SPRN_VRSAVE);
+ err |= __put_user(tsk->thread.vrsave, (u32 __user *)&v_regs[33]);
if (msr & MSR_VEC)
- err |= __put_user(current->thread.transact_vrsave,
+ err |= __put_user(tsk->thread.transact_vrsave,
(u32 __user *)&tm_v_regs[33]);
else
- err |= __put_user(current->thread.vrsave,
+ err |= __put_user(tsk->thread.vrsave,
(u32 __user *)&tm_v_regs[33]);
#else /* CONFIG_ALTIVEC */
@@ -262,11 +268,11 @@ static long setup_tm_sigcontexts(struct sigcontext __user *sc,
#endif /* CONFIG_ALTIVEC */
/* copy fpr regs and fpscr */
- err |= copy_fpr_to_user(&sc->fp_regs, current);
+ err |= copy_fpr_to_user(&sc->fp_regs, tsk);
if (msr & MSR_FP)
- err |= copy_transact_fpr_to_user(&tm_sc->fp_regs, current);
+ err |= copy_transact_fpr_to_user(&tm_sc->fp_regs, tsk);
else
- err |= copy_fpr_to_user(&tm_sc->fp_regs, current);
+ err |= copy_fpr_to_user(&tm_sc->fp_regs, tsl);
#ifdef CONFIG_VSX
/*
@@ -274,17 +280,17 @@ static long setup_tm_sigcontexts(struct sigcontext __user *sc,
* then out to userspace. Update v_regs to point after the
* VMX data.
*/
- if (current->thread.used_vsr) {
- flush_vsx_to_thread(current);
+ if (tsk->thread.used_vsr) {
+ flush_vsx_to_thread(tsk);
v_regs += ELF_NVRREG;
tm_v_regs += ELF_NVRREG;
- err |= copy_vsx_to_user(v_regs, current);
+ err |= copy_vsx_to_user(v_regs, tsk);
if (msr & MSR_VSX)
- err |= copy_transact_vsx_to_user(tm_v_regs, current);
+ err |= copy_transact_vsx_to_user(tm_v_regs, tsk);
else
- err |= copy_vsx_to_user(tm_v_regs, current);
+ err |= copy_vsx_to_user(tm_v_regs, tsk);
/* set MSR_VSX in the MSR value in the frame to
* indicate that sc->vs_reg) contains valid data.
@@ -298,7 +304,7 @@ static long setup_tm_sigcontexts(struct sigcontext __user *sc,
WARN_ON(!FULL_REGS(regs));
err |= __copy_to_user(&tm_sc->gp_regs, regs, GP_REGS_SIZE);
err |= __copy_to_user(&sc->gp_regs,
- ¤t->thread.ckpt_regs, GP_REGS_SIZE);
+ &tsk->thread.ckpt_regs, GP_REGS_SIZE);
err |= __put_user(msr, &tm_sc->gp_regs[PT_MSR]);
err |= __put_user(msr, &sc->gp_regs[PT_MSR]);
err |= __put_user(signr, &sc->signal);
@@ -314,7 +320,7 @@ static long setup_tm_sigcontexts(struct sigcontext __user *sc,
* Restore the sigcontext from the signal frame.
*/
-static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig,
+static long restore_sigcontext(struct task_struct *tsk, sigset_t *set, int sig,
struct sigcontext __user *sc)
{
#ifdef CONFIG_ALTIVEC
@@ -323,10 +329,13 @@ static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig,
unsigned long err = 0;
unsigned long save_r13 = 0;
unsigned long msr;
+ struct pt_regs *regs = tsk->thread.regs;
#ifdef CONFIG_VSX
int i;
#endif
+ BUG_ON(tsk != current);
+
/* If this is not a signal return, we preserve the TLS in r13 */
if (!sig)
save_r13 = regs->gpr[13];
@@ -356,7 +365,7 @@ static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig,
/*
* Force reload of FP/VEC.
- * This has to be done before copying stuff into current->thread.fpr/vr
+ * This has to be done before copying stuff into tsk->thread.fpr/vr
* for the reasons explained in the previous comment.
*/
regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX);
@@ -369,20 +378,20 @@ static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig,
return -EFAULT;
/* Copy 33 vec registers (vr0..31 and vscr) from the stack */
if (v_regs != NULL && (msr & MSR_VEC) != 0)
- err |= __copy_from_user(¤t->thread.vr_state, v_regs,
+ err |= __copy_from_user(&tsk->thread.vr_state, v_regs,
33 * sizeof(vector128));
- else if (current->thread.used_vr)
- memset(¤t->thread.vr_state, 0, 33 * sizeof(vector128));
+ else if (tsk->thread.used_vr)
+ memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128));
/* Always get VRSAVE back */
if (v_regs != NULL)
- err |= __get_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
+ err |= __get_user(tsk->thread.vrsave, (u32 __user *)&v_regs[33]);
else
- current->thread.vrsave = 0;
+ tsk->thread.vrsave = 0;
if (cpu_has_feature(CPU_FTR_ALTIVEC))
- mtspr(SPRN_VRSAVE, current->thread.vrsave);
+ mtspr(SPRN_VRSAVE, tsk->thread.vrsave);
#endif /* CONFIG_ALTIVEC */
/* restore floating point */
- err |= copy_fpr_from_user(current, &sc->fp_regs);
+ err |= copy_fpr_from_user(tsk, &sc->fp_regs);
#ifdef CONFIG_VSX
/*
* Get additional VSX data. Update v_regs to point after the
@@ -391,10 +400,10 @@ static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig,
*/
v_regs += ELF_NVRREG;
if ((msr & MSR_VSX) != 0)
- err |= copy_vsx_from_user(current, v_regs);
+ err |= copy_vsx_from_user(tsk, v_regs);
else
for (i = 0; i < 32 ; i++)
- current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
+ tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
#endif
return err;
}
@@ -404,7 +413,7 @@ static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig,
* Restore the two sigcontexts from the frame of a transactional processes.
*/
-static long restore_tm_sigcontexts(struct pt_regs *regs,
+static long restore_tm_sigcontexts(struct task_struct *tsk,
struct sigcontext __user *sc,
struct sigcontext __user *tm_sc)
{
@@ -413,12 +422,16 @@ static long restore_tm_sigcontexts(struct pt_regs *regs,
#endif
unsigned long err = 0;
unsigned long msr;
+ struct pt_regs *regs = tsk->thread.regs;
#ifdef CONFIG_VSX
int i;
#endif
+
+ BUG_ON(tsk != current);
+
/* copy the GPRs */
err |= __copy_from_user(regs->gpr, tm_sc->gp_regs, sizeof(regs->gpr));
- err |= __copy_from_user(¤t->thread.ckpt_regs, sc->gp_regs,
+ err |= __copy_from_user(&tsk->thread.ckpt_regs, sc->gp_regs,
sizeof(regs->gpr));
/*
@@ -430,7 +443,7 @@ static long restore_tm_sigcontexts(struct pt_regs *regs,
* we don't need to re-copy them here.
*/
err |= __get_user(regs->nip, &tm_sc->gp_regs[PT_NIP]);
- err |= __get_user(current->thread.tm_tfhar, &sc->gp_regs[PT_NIP]);
+ err |= __get_user(tsk->thread.tm_tfhar, &sc->gp_regs[PT_NIP]);
/* get MSR separately, transfer the LE bit if doing signal return */
err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
@@ -449,13 +462,13 @@ static long restore_tm_sigcontexts(struct pt_regs *regs,
err |= __get_user(regs->link, &tm_sc->gp_regs[PT_LNK]);
err |= __get_user(regs->xer, &tm_sc->gp_regs[PT_XER]);
err |= __get_user(regs->ccr, &tm_sc->gp_regs[PT_CCR]);
- err |= __get_user(current->thread.ckpt_regs.ctr,
+ err |= __get_user(tsk->thread.ckpt_regs.ctr,
&sc->gp_regs[PT_CTR]);
- err |= __get_user(current->thread.ckpt_regs.link,
+ err |= __get_user(tsk->thread.ckpt_regs.link,
&sc->gp_regs[PT_LNK]);
- err |= __get_user(current->thread.ckpt_regs.xer,
+ err |= __get_user(tsk->thread.ckpt_regs.xer,
&sc->gp_regs[PT_XER]);
- err |= __get_user(current->thread.ckpt_regs.ccr,
+ err |= __get_user(tsk->thread.ckpt_regs.ccr,
&sc->gp_regs[PT_CCR]);
/* These regs are not checkpointed; they can go in 'regs'. */
@@ -466,7 +479,7 @@ static long restore_tm_sigcontexts(struct pt_regs *regs,
/*
* Force reload of FP/VEC.
- * This has to be done before copying stuff into current->thread.fpr/vr
+ * This has to be done before copying stuff into tsk->thread.fpr/vr
* for the reasons explained in the previous comment.
*/
regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX);
@@ -483,32 +496,32 @@ static long restore_tm_sigcontexts(struct pt_regs *regs,
return -EFAULT;
/* Copy 33 vec registers (vr0..31 and vscr) from the stack */
if (v_regs != NULL && tm_v_regs != NULL && (msr & MSR_VEC) != 0) {
- err |= __copy_from_user(¤t->thread.vr_state, v_regs,
+ err |= __copy_from_user(&tsk->thread.vr_state, v_regs,
33 * sizeof(vector128));
- err |= __copy_from_user(¤t->thread.transact_vr, tm_v_regs,
+ err |= __copy_from_user(&tsk->thread.transact_vr, tm_v_regs,
33 * sizeof(vector128));
}
- else if (current->thread.used_vr) {
- memset(¤t->thread.vr_state, 0, 33 * sizeof(vector128));
- memset(¤t->thread.transact_vr, 0, 33 * sizeof(vector128));
+ else if (tsk->thread.used_vr) {
+ memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128));
+ memset(&tsk->thread.transact_vr, 0, 33 * sizeof(vector128));
}
/* Always get VRSAVE back */
if (v_regs != NULL && tm_v_regs != NULL) {
- err |= __get_user(current->thread.vrsave,
+ err |= __get_user(tsk->thread.vrsave,
(u32 __user *)&v_regs[33]);
- err |= __get_user(current->thread.transact_vrsave,
+ err |= __get_user(tsk->thread.transact_vrsave,
(u32 __user *)&tm_v_regs[33]);
}
else {
- current->thread.vrsave = 0;
- current->thread.transact_vrsave = 0;
+ tsk->thread.vrsave = 0;
+ tsk->thread.transact_vrsave = 0;
}
if (cpu_has_feature(CPU_FTR_ALTIVEC))
- mtspr(SPRN_VRSAVE, current->thread.vrsave);
+ mtspr(SPRN_VRSAVE, tsk->thread.vrsave);
#endif /* CONFIG_ALTIVEC */
/* restore floating point */
- err |= copy_fpr_from_user(current, &sc->fp_regs);
- err |= copy_transact_fpr_from_user(current, &tm_sc->fp_regs);
+ err |= copy_fpr_from_user(tsk, &sc->fp_regs);
+ err |= copy_transact_fpr_from_user(tsk, &tm_sc->fp_regs);
#ifdef CONFIG_VSX
/*
* Get additional VSX data. Update v_regs to point after the
@@ -518,29 +531,29 @@ static long restore_tm_sigcontexts(struct pt_regs *regs,
if (v_regs && ((msr & MSR_VSX) != 0)) {
v_regs += ELF_NVRREG;
tm_v_regs += ELF_NVRREG;
- err |= copy_vsx_from_user(current, v_regs);
- err |= copy_transact_vsx_from_user(current, tm_v_regs);
+ err |= copy_vsx_from_user(tsk, v_regs);
+ err |= copy_transact_vsx_from_user(tsk, tm_v_regs);
} else {
for (i = 0; i < 32 ; i++) {
- current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
- current->thread.transact_fp.fpr[i][TS_VSRLOWOFFSET] = 0;
+ tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
+ tsk->thread.transact_fp.fpr[i][TS_VSRLOWOFFSET] = 0;
}
}
#endif
tm_enable();
/* Make sure the transaction is marked as failed */
- current->thread.tm_texasr |= TEXASR_FS;
+ tsk->thread.tm_texasr |= TEXASR_FS;
/* This loads the checkpointed FP/VEC state, if used */
- tm_recheckpoint(¤t->thread, msr);
+ tm_recheckpoint(&tsk->thread, msr);
/* This loads the speculative FP/VEC state, if used */
if (msr & MSR_FP) {
- do_load_up_transact_fpu(¤t->thread);
- regs->msr |= (MSR_FP | current->thread.fpexc_mode);
+ do_load_up_transact_fpu(&tsk->thread);
+ regs->msr |= (MSR_FP | tsk->thread.fpexc_mode);
}
#ifdef CONFIG_ALTIVEC
if (msr & MSR_VEC) {
- do_load_up_transact_altivec(¤t->thread);
+ do_load_up_transact_altivec(&tsk->thread);
regs->msr |= MSR_VEC;
}
#endif
@@ -594,6 +607,8 @@ int sys_swapcontext(struct ucontext __user *old_ctx,
unsigned long new_msr = 0;
int ctx_has_vsx_region = 0;
+ BUG_ON(regs != current->thread.regs);
+
if (new_ctx &&
get_user(new_msr, &new_ctx->uc_mcontext.gp_regs[PT_MSR]))
return -EFAULT;
@@ -616,7 +631,7 @@ int sys_swapcontext(struct ucontext __user *old_ctx,
if (old_ctx != NULL) {
if (!access_ok(VERIFY_WRITE, old_ctx, ctx_size)
- || setup_sigcontext(&old_ctx->uc_mcontext, regs, 0, NULL, 0,
+ || setup_sigcontext(&old_ctx->uc_mcontext, current, 0, NULL, 0,
ctx_has_vsx_region)
|| __copy_to_user(&old_ctx->uc_sigmask,
¤t->blocked, sizeof(sigset_t)))
@@ -644,7 +659,7 @@ int sys_swapcontext(struct ucontext __user *old_ctx,
if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set)))
do_exit(SIGSEGV);
set_current_blocked(&set);
- if (restore_sigcontext(regs, NULL, 0, &new_ctx->uc_mcontext))
+ if (restore_sigcontext(current, NULL, 0, &new_ctx->uc_mcontext))
do_exit(SIGSEGV);
/* This returns like rt_sigreturn */
@@ -667,6 +682,8 @@ int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
unsigned long msr;
#endif
+ BUG_ON(current->thread.regs != regs);
+
/* Always make any pending restarted system calls return -EINTR */
current->restart_block.fn = do_no_restart_syscall;
@@ -684,14 +701,14 @@ int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
struct ucontext __user *uc_transact;
if (__get_user(uc_transact, &uc->uc_link))
goto badframe;
- if (restore_tm_sigcontexts(regs, &uc->uc_mcontext,
+ if (restore_tm_sigcontexts(current, &uc->uc_mcontext,
&uc_transact->uc_mcontext))
goto badframe;
}
else
/* Fall through, for non-TM restore */
#endif
- if (restore_sigcontext(regs, NULL, 1, &uc->uc_mcontext))
+ if (restore_sigcontext(current, NULL, 1, &uc->uc_mcontext))
goto badframe;
if (restore_altstack(&uc->uc_stack))
@@ -710,13 +727,17 @@ badframe:
return 0;
}
-int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs)
+int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
+ struct task_struct *tsk)
{
struct rt_sigframe __user *frame;
unsigned long newsp = 0;
long err = 0;
+ struct pt_regs *regs = tsk->thread.regs;
+
+ BUG_ON(tsk != current);
- frame = get_sigframe(ksig, get_tm_stackpointer(regs), sizeof(*frame), 0);
+ frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 0);
if (unlikely(frame == NULL))
goto badframe;
@@ -737,14 +758,13 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs
err |= __put_user(&frame->uc_transact, &frame->uc.uc_link);
err |= setup_tm_sigcontexts(&frame->uc.uc_mcontext,
&frame->uc_transact.uc_mcontext,
- regs, ksig->sig,
- NULL,
+ tsk, ksig->sig, NULL,
(unsigned long)ksig->ka.sa.sa_handler);
} else
#endif
{
err |= __put_user(0, &frame->uc.uc_link);
- err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, ksig->sig,
+ err |= setup_sigcontext(&frame->uc.uc_mcontext, tsk, ksig->sig,
NULL, (unsigned long)ksig->ka.sa.sa_handler,
1);
}
@@ -753,11 +773,11 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs
goto badframe;
/* Make sure signal handler doesn't get spurious FP exceptions */
- current->thread.fp_state.fpscr = 0;
+ tsk->thread.fp_state.fpscr = 0;
/* Set up to return from userspace. */
- if (vdso64_rt_sigtramp && current->mm->context.vdso_base) {
- regs->link = current->mm->context.vdso_base + vdso64_rt_sigtramp;
+ if (vdso64_rt_sigtramp && tsk->mm->context.vdso_base) {
+ regs->link = tsk->mm->context.vdso_base + vdso64_rt_sigtramp;
} else {
err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]);
if (err)
@@ -807,7 +827,7 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs
badframe:
if (show_unhandled_signals)
printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
- current->comm, current->pid, "setup_rt_frame",
+ tsk->comm, tsk->pid, "setup_rt_frame",
(long)frame, regs->nip, regs->link);
return 1;
--
2.9.3
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