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xtensa: implement TIE regset
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Put all coprocessors and non-coprocessor TIE state into the REGSET_TIE.
Mark TIE regset with NT_PRFPREG note type.
Reimplement ptrace_getxregs and ptrace_setxregs using REGSET_TIE.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
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Max Filippov committed Dec 17, 2018
1 parent 06fbac8 commit 1819afc
Showing 1 changed file with 87 additions and 78 deletions.
165 changes: 87 additions & 78 deletions arch/xtensa/kernel/ptrace.c
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Original file line number Diff line number Diff line change
Expand Up @@ -111,8 +111,82 @@ static int gpr_set(struct task_struct *target,
return 0;
}

static int tie_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
int ret;
struct pt_regs *regs = task_pt_regs(target);
struct thread_info *ti = task_thread_info(target);
elf_xtregs_t *newregs = kzalloc(sizeof(elf_xtregs_t), GFP_KERNEL);

if (!newregs)
return -ENOMEM;

newregs->opt = regs->xtregs_opt;
newregs->user = ti->xtregs_user;

#if XTENSA_HAVE_COPROCESSORS
/* Flush all coprocessor registers to memory. */
coprocessor_flush_all(ti);
newregs->cp0 = ti->xtregs_cp.cp0;
newregs->cp1 = ti->xtregs_cp.cp1;
newregs->cp2 = ti->xtregs_cp.cp2;
newregs->cp3 = ti->xtregs_cp.cp3;
newregs->cp4 = ti->xtregs_cp.cp4;
newregs->cp5 = ti->xtregs_cp.cp5;
newregs->cp6 = ti->xtregs_cp.cp6;
newregs->cp7 = ti->xtregs_cp.cp7;
#endif
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
newregs, 0, -1);
kfree(newregs);
return ret;
}

static int tie_set(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
int ret;
struct pt_regs *regs = task_pt_regs(target);
struct thread_info *ti = task_thread_info(target);
elf_xtregs_t *newregs = kzalloc(sizeof(elf_xtregs_t), GFP_KERNEL);

if (!newregs)
return -ENOMEM;

ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
newregs, 0, -1);

if (ret)
goto exit;
regs->xtregs_opt = newregs->opt;
ti->xtregs_user = newregs->user;

#if XTENSA_HAVE_COPROCESSORS
/* Flush all coprocessors before we overwrite them. */
coprocessor_flush_all(ti);
coprocessor_release_all(ti);
ti->xtregs_cp.cp0 = newregs->cp0;
ti->xtregs_cp.cp1 = newregs->cp1;
ti->xtregs_cp.cp2 = newregs->cp2;
ti->xtregs_cp.cp3 = newregs->cp3;
ti->xtregs_cp.cp4 = newregs->cp4;
ti->xtregs_cp.cp5 = newregs->cp5;
ti->xtregs_cp.cp6 = newregs->cp6;
ti->xtregs_cp.cp7 = newregs->cp7;
#endif
exit:
kfree(newregs);
return ret;
}

enum xtensa_regset {
REGSET_GPR,
REGSET_TIE,
};

static const struct user_regset xtensa_regsets[] = {
Expand All @@ -122,7 +196,15 @@ static const struct user_regset xtensa_regsets[] = {
.size = sizeof(u32),
.align = sizeof(u32),
.get = gpr_get,
.set = gpr_set
.set = gpr_set,
},
[REGSET_TIE] = {
.core_note_type = NT_PRFPREG,
.n = sizeof(elf_xtregs_t) / sizeof(u32),
.size = sizeof(u32),
.align = sizeof(u32),
.get = tie_get,
.set = tie_set,
},
};

Expand Down Expand Up @@ -169,89 +251,16 @@ static int ptrace_setregs(struct task_struct *child, void __user *uregs)
0, sizeof(xtensa_gregset_t), uregs);
}


#if XTENSA_HAVE_COPROCESSORS
#define CP_OFFSETS(cp) \
{ \
.elf_xtregs_offset = offsetof(elf_xtregs_t, cp), \
.ti_offset = offsetof(struct thread_info, xtregs_cp.cp), \
.sz = sizeof(xtregs_ ## cp ## _t), \
}

static const struct {
size_t elf_xtregs_offset;
size_t ti_offset;
size_t sz;
} cp_offsets[] = {
CP_OFFSETS(cp0),
CP_OFFSETS(cp1),
CP_OFFSETS(cp2),
CP_OFFSETS(cp3),
CP_OFFSETS(cp4),
CP_OFFSETS(cp5),
CP_OFFSETS(cp6),
CP_OFFSETS(cp7),
};
#endif

static int ptrace_getxregs(struct task_struct *child, void __user *uregs)
{
struct pt_regs *regs = task_pt_regs(child);
struct thread_info *ti = task_thread_info(child);
elf_xtregs_t __user *xtregs = uregs;
int ret = 0;
int i __maybe_unused;

if (!access_ok(VERIFY_WRITE, uregs, sizeof(elf_xtregs_t)))
return -EIO;

#if XTENSA_HAVE_COPROCESSORS
/* Flush all coprocessor registers to memory. */
coprocessor_flush_all(ti);

for (i = 0; i < ARRAY_SIZE(cp_offsets); ++i)
ret |= __copy_to_user((char __user *)xtregs +
cp_offsets[i].elf_xtregs_offset,
(const char *)ti +
cp_offsets[i].ti_offset,
cp_offsets[i].sz);
#endif
ret |= __copy_to_user(&xtregs->opt, &regs->xtregs_opt,
sizeof(xtregs->opt));
ret |= __copy_to_user(&xtregs->user,&ti->xtregs_user,
sizeof(xtregs->user));

return ret ? -EFAULT : 0;
return copy_regset_to_user(child, &user_xtensa_view, REGSET_TIE,
0, sizeof(elf_xtregs_t), uregs);
}

static int ptrace_setxregs(struct task_struct *child, void __user *uregs)
{
struct thread_info *ti = task_thread_info(child);
struct pt_regs *regs = task_pt_regs(child);
elf_xtregs_t *xtregs = uregs;
int ret = 0;
int i __maybe_unused;

if (!access_ok(VERIFY_READ, uregs, sizeof(elf_xtregs_t)))
return -EFAULT;

#if XTENSA_HAVE_COPROCESSORS
/* Flush all coprocessors before we overwrite them. */
coprocessor_flush_all(ti);
coprocessor_release_all(ti);

for (i = 0; i < ARRAY_SIZE(cp_offsets); ++i)
ret |= __copy_from_user((char *)ti + cp_offsets[i].ti_offset,
(const char __user *)xtregs +
cp_offsets[i].elf_xtregs_offset,
cp_offsets[i].sz);
#endif
ret |= __copy_from_user(&regs->xtregs_opt, &xtregs->opt,
sizeof(xtregs->opt));
ret |= __copy_from_user(&ti->xtregs_user, &xtregs->user,
sizeof(xtregs->user));

return ret ? -EFAULT : 0;
return copy_regset_from_user(child, &user_xtensa_view, REGSET_TIE,
0, sizeof(elf_xtregs_t), uregs);
}

static int ptrace_peekusr(struct task_struct *child, long regno,
Expand Down

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