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powerpc: Clean up copy_to/from_user for vsx and fpr
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This merges and cleans up some of the ugly copy/to from user code
which is required for the new fpr and vsx layout in the thread_struct.

Also fixes some hard coded buffer sizes and removes a redundant
fpr_flush_to_thread.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
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Michael Neuling authored and Paul Mackerras committed Jul 3, 2008
1 parent 2d1b202 commit 6a274c0
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Showing 3 changed files with 96 additions and 66 deletions.
10 changes: 10 additions & 0 deletions arch/powerpc/kernel/signal.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -24,6 +24,16 @@ extern int handle_rt_signal32(unsigned long sig, struct k_sigaction *ka,
siginfo_t *info, sigset_t *oldset,
struct pt_regs *regs);

extern unsigned long copy_fpr_to_user(void __user *to,
struct task_struct *task);
extern unsigned long copy_fpr_from_user(struct task_struct *task,
void __user *from);
#ifdef CONFIG_VSX
extern unsigned long copy_vsx_to_user(void __user *to,
struct task_struct *task);
extern unsigned long copy_vsx_from_user(struct task_struct *task,
void __user *from);
#endif

#ifdef CONFIG_PPC64

Expand Down
109 changes: 75 additions & 34 deletions arch/powerpc/kernel/signal_32.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -328,6 +328,75 @@ struct rt_sigframe {
int abigap[56];
};

#ifdef CONFIG_VSX
unsigned long copy_fpr_to_user(void __user *to,
struct task_struct *task)
{
double buf[ELF_NFPREG];
int i;

/* save FPR copy to local buffer then write to the thread_struct */
for (i = 0; i < (ELF_NFPREG - 1) ; i++)
buf[i] = task->thread.TS_FPR(i);
memcpy(&buf[i], &task->thread.fpscr, sizeof(double));
return __copy_to_user(to, buf, ELF_NFPREG * sizeof(double));
}

unsigned long copy_fpr_from_user(struct task_struct *task,
void __user *from)
{
double buf[ELF_NFPREG];
int i;

if (__copy_from_user(buf, from, ELF_NFPREG * sizeof(double)))
return 1;
for (i = 0; i < (ELF_NFPREG - 1) ; i++)
task->thread.TS_FPR(i) = buf[i];
memcpy(&task->thread.fpscr, &buf[i], sizeof(double));

return 0;
}

unsigned long copy_vsx_to_user(void __user *to,
struct task_struct *task)
{
double buf[ELF_NVSRHALFREG];
int i;

/* save FPR copy to local buffer then write to the thread_struct */
for (i = 0; i < ELF_NVSRHALFREG; i++)
buf[i] = task->thread.fpr[i][TS_VSRLOWOFFSET];
return __copy_to_user(to, buf, ELF_NVSRHALFREG * sizeof(double));
}

unsigned long copy_vsx_from_user(struct task_struct *task,
void __user *from)
{
double buf[ELF_NVSRHALFREG];
int i;

if (__copy_from_user(buf, from, ELF_NVSRHALFREG * sizeof(double)))
return 1;
for (i = 0; i < ELF_NVSRHALFREG ; i++)
task->thread.fpr[i][TS_VSRLOWOFFSET] = buf[i];
return 0;
}
#else
inline unsigned long copy_fpr_to_user(void __user *to,
struct task_struct *task)
{
return __copy_to_user(to, task->thread.fpr,
ELF_NFPREG * sizeof(double));
}

inline unsigned long copy_fpr_from_user(struct task_struct *task,
void __user *from)
{
return __copy_from_user(task->thread.fpr, from,
ELF_NFPREG * sizeof(double));
}
#endif

/*
* Save the current user registers on the user stack.
* We only save the altivec/spe registers if the process has used
Expand All @@ -337,10 +406,6 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
int sigret)
{
unsigned long msr = regs->msr;
#ifdef CONFIG_VSX
double buf[32];
int i;
#endif

/* Make sure floating point registers are stored in regs */
flush_fp_to_thread(current);
Expand Down Expand Up @@ -370,14 +435,9 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
if (__put_user(current->thread.vrsave, (u32 __user *)&frame->mc_vregs[32]))
return 1;
#endif /* CONFIG_ALTIVEC */
#ifdef CONFIG_VSX
/* save FPR copy to local buffer then write to the thread_struct */
flush_fp_to_thread(current);
for (i = 0; i < 32 ; i++)
buf[i] = current->thread.TS_FPR(i);
memcpy(&buf[i], &current->thread.fpscr, sizeof(double));
if (__copy_to_user(&frame->mc_fregs, buf, ELF_NFPREG * sizeof(double)))
if (copy_fpr_to_user(&frame->mc_fregs, current))
return 1;
#ifdef CONFIG_VSX
/*
* Copy VSR 0-31 upper half from thread_struct to local
* buffer, then write that to userspace. Also set MSR_VSX in
Expand All @@ -386,18 +446,10 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
*/
if (current->thread.used_vsr) {
flush_vsx_to_thread(current);
for (i = 0; i < 32 ; i++)
buf[i] = current->thread.fpr[i][TS_VSRLOWOFFSET];
if (__copy_to_user(&frame->mc_vsregs, buf,
ELF_NVSRHALFREG * sizeof(double)))
if (copy_vsx_to_user(&frame->mc_vsregs, current))
return 1;
msr |= MSR_VSX;
}
#else
/* save floating-point registers */
if (__copy_to_user(&frame->mc_fregs, current->thread.fpr,
ELF_NFPREG * sizeof(double)))
return 1;
#endif /* CONFIG_VSX */
#ifdef CONFIG_SPE
/* save spe registers */
Expand Down Expand Up @@ -442,7 +494,6 @@ static long restore_user_regs(struct pt_regs *regs,
unsigned int save_r2 = 0;
unsigned long msr;
#ifdef CONFIG_VSX
double buf[32];
int i;
#endif

Expand Down Expand Up @@ -490,13 +541,10 @@ static long restore_user_regs(struct pt_regs *regs,
if (__get_user(current->thread.vrsave, (u32 __user *)&sr->mc_vregs[32]))
return 1;
#endif /* CONFIG_ALTIVEC */
if (copy_fpr_from_user(current, &sr->mc_fregs))
return 1;

#ifdef CONFIG_VSX
if (__copy_from_user(buf, &sr->mc_fregs,sizeof(sr->mc_fregs)))
return 1;
for (i = 0; i < 32 ; i++)
current->thread.TS_FPR(i) = buf[i];
memcpy(&current->thread.fpscr, &buf[i], sizeof(double));
/*
* Force the process to reload the VSX registers from
* current->thread when it next does VSX instruction.
Expand All @@ -507,18 +555,11 @@ static long restore_user_regs(struct pt_regs *regs,
* Restore altivec registers from the stack to a local
* buffer, then write this out to the thread_struct
*/
if (__copy_from_user(buf, &sr->mc_vsregs,
sizeof(sr->mc_vsregs)))
if (copy_vsx_from_user(current, &sr->mc_vsregs))
return 1;
for (i = 0; i < 32 ; i++)
current->thread.fpr[i][TS_VSRLOWOFFSET] = buf[i];
} else if (current->thread.used_vsr)
for (i = 0; i < 32 ; i++)
current->thread.fpr[i][TS_VSRLOWOFFSET] = 0;
#else
if (__copy_from_user(current->thread.fpr, &sr->mc_fregs,
sizeof(sr->mc_fregs)))
return 1;
#endif /* CONFIG_VSX */
/*
* force the process to reload the FP registers from
Expand Down
43 changes: 11 additions & 32 deletions arch/powerpc/kernel/signal_64.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -89,10 +89,6 @@ static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
#endif
unsigned long msr = regs->msr;
long err = 0;
#ifdef CONFIG_VSX
double buf[FP_REGS_SIZE];
int i;
#endif

flush_fp_to_thread(current);

Expand All @@ -117,12 +113,9 @@ static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
err |= __put_user(0, &sc->v_regs);
#endif /* CONFIG_ALTIVEC */
flush_fp_to_thread(current);
/* copy fpr regs and fpscr */
err |= copy_fpr_to_user(&sc->fp_regs, current);
#ifdef CONFIG_VSX
/* Copy FP to local buffer then write that out */
for (i = 0; i < 32 ; i++)
buf[i] = current->thread.TS_FPR(i);
memcpy(&buf[i], &current->thread.fpscr, sizeof(double));
err |= __copy_to_user(&sc->fp_regs, buf, FP_REGS_SIZE);
/*
* Copy VSX low doubleword to local buffer for formatting,
* then out to userspace. Update v_regs to point after the
Expand All @@ -131,17 +124,12 @@ static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
if (current->thread.used_vsr) {
flush_vsx_to_thread(current);
v_regs += ELF_NVRREG;
for (i = 0; i < 32 ; i++)
buf[i] = current->thread.fpr[i][TS_VSRLOWOFFSET];
err |= __copy_to_user(v_regs, buf, 32 * sizeof(double));
err |= copy_vsx_to_user(v_regs, current);
/* set MSR_VSX in the MSR value in the frame to
* indicate that sc->vs_reg) contains valid data.
*/
msr |= MSR_VSX;
}
#else /* CONFIG_VSX */
/* copy fpr regs and fpscr */
err |= __copy_to_user(&sc->fp_regs, &current->thread.fpr, FP_REGS_SIZE);
#endif /* CONFIG_VSX */
err |= __put_user(&sc->gp_regs, &sc->regs);
WARN_ON(!FULL_REGS(regs));
Expand All @@ -164,14 +152,13 @@ static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig,
{
#ifdef CONFIG_ALTIVEC
elf_vrreg_t __user *v_regs;
#endif
#ifdef CONFIG_VSX
double buf[FP_REGS_SIZE];
int i;
#endif
unsigned long err = 0;
unsigned long save_r13 = 0;
unsigned long msr;
#ifdef CONFIG_VSX
int i;
#endif

/* If this is not a signal return, we preserve the TLS in r13 */
if (!sig)
Expand Down Expand Up @@ -234,30 +221,22 @@ static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig,
else
current->thread.vrsave = 0;
#endif /* CONFIG_ALTIVEC */
#ifdef CONFIG_VSX
/* restore floating point */
err |= __copy_from_user(buf, &sc->fp_regs, FP_REGS_SIZE);
if (err)
return err;
for (i = 0; i < 32 ; i++)
current->thread.TS_FPR(i) = buf[i];
memcpy(&current->thread.fpscr, &buf[i], sizeof(double));

err |= copy_fpr_from_user(current, &sc->fp_regs);
#ifdef CONFIG_VSX
/*
* Get additional VSX data. Update v_regs to point after the
* VMX data. Copy VSX low doubleword from userspace to local
* buffer for formatting, then into the taskstruct.
*/
v_regs += ELF_NVRREG;
if ((msr & MSR_VSX) != 0)
err |= __copy_from_user(buf, v_regs, 32 * sizeof(double));
err |= copy_vsx_from_user(current, v_regs);
else
memset(buf, 0, 32 * sizeof(double));
for (i = 0; i < 32 ; i++)
current->thread.fpr[i][TS_VSRLOWOFFSET] = 0;

for (i = 0; i < 32 ; i++)
current->thread.fpr[i][TS_VSRLOWOFFSET] = buf[i];
#else
err |= __copy_from_user(&current->thread.fpr, &sc->fp_regs, FP_REGS_SIZE);
#endif
return err;
}
Expand Down

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