x86: switch to ->regset_get()

All instances of ->get() in arch/x86 switched; that might or might
not be worth splitting up.  Notes:

	* for xstateregs_get() the amount we want to store is determined at
the boot time; see init_xstate_size() and update_regset_xstate_info() for
details.  task->thread.fpu.state.xsave ends with a flexible array member and
the amount of data in it depends upon the FPU features supported/enabled.

	* fpregs_get() writes slightly less than full ->thread.fpu.state.fsave
(the last word is not copied); we pass the full size of state.fsave and let
membuf_write() trim to the amount declared by regset - __regset_get() will
make sure that the space in buffer is no more than that.

	* copy_xstate_to_user() and its helpers are gone now.

	* fpregs_soft_get() was getting user_regset_copyout() arguments
wrong.  Since "x86: x86 user_regset math_emu" back in 2008...  I really
doubt that it's worth splitting out for -stable, though - you need
a 486SX box for that to trigger...

[Kevin's braino fix for copy_xstate_to_kernel() essentially duplicated here]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
2020-02-18 12:14:34 -05:00
parent 7717cb9bdd
commit 0557d64d98
9 changed files with 83 additions and 259 deletions

View File

@@ -433,26 +433,12 @@ static unsigned long getreg(struct task_struct *task, unsigned long offset)
static int genregs_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
struct membuf to)
{
if (kbuf) {
unsigned long *k = kbuf;
while (count >= sizeof(*k)) {
*k++ = getreg(target, pos);
count -= sizeof(*k);
pos += sizeof(*k);
}
} else {
unsigned long __user *u = ubuf;
while (count >= sizeof(*u)) {
if (__put_user(getreg(target, pos), u++))
return -EFAULT;
count -= sizeof(*u);
pos += sizeof(*u);
}
}
int reg;
for (reg = 0; to.left; reg++)
membuf_store(&to, getreg(target, reg * sizeof(unsigned long)));
return 0;
}
@@ -716,16 +702,14 @@ static int ioperm_active(struct task_struct *target,
static int ioperm_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
struct membuf to)
{
struct io_bitmap *iobm = target->thread.io_bitmap;
if (!iobm)
return -ENXIO;
return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
iobm->bitmap, 0, IO_BITMAP_BYTES);
return membuf_write(&to, iobm->bitmap, IO_BITMAP_BYTES);
}
/*
@@ -1003,28 +987,15 @@ static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
static int genregs32_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
struct membuf to)
{
if (kbuf) {
compat_ulong_t *k = kbuf;
while (count >= sizeof(*k)) {
getreg32(target, pos, k++);
count -= sizeof(*k);
pos += sizeof(*k);
}
} else {
compat_ulong_t __user *u = ubuf;
while (count >= sizeof(*u)) {
compat_ulong_t word;
getreg32(target, pos, &word);
if (__put_user(word, u++))
return -EFAULT;
count -= sizeof(*u);
pos += sizeof(*u);
}
}
int reg;
for (reg = 0; to.left; reg++) {
u32 val;
getreg32(target, reg * 4, &val);
membuf_store(&to, val);
}
return 0;
}
@@ -1234,25 +1205,25 @@ static struct user_regset x86_64_regsets[] __ro_after_init = {
.core_note_type = NT_PRSTATUS,
.n = sizeof(struct user_regs_struct) / sizeof(long),
.size = sizeof(long), .align = sizeof(long),
.get = genregs_get, .set = genregs_set
.regset_get = genregs_get, .set = genregs_set
},
[REGSET_FP] = {
.core_note_type = NT_PRFPREG,
.n = sizeof(struct user_i387_struct) / sizeof(long),
.size = sizeof(long), .align = sizeof(long),
.active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
.active = regset_xregset_fpregs_active, .regset_get = xfpregs_get, .set = xfpregs_set
},
[REGSET_XSTATE] = {
.core_note_type = NT_X86_XSTATE,
.size = sizeof(u64), .align = sizeof(u64),
.active = xstateregs_active, .get = xstateregs_get,
.active = xstateregs_active, .regset_get = xstateregs_get,
.set = xstateregs_set
},
[REGSET_IOPERM64] = {
.core_note_type = NT_386_IOPERM,
.n = IO_BITMAP_LONGS,
.size = sizeof(long), .align = sizeof(long),
.active = ioperm_active, .get = ioperm_get
.active = ioperm_active, .regset_get = ioperm_get
},
};
@@ -1275,24 +1246,24 @@ static struct user_regset x86_32_regsets[] __ro_after_init = {
.core_note_type = NT_PRSTATUS,
.n = sizeof(struct user_regs_struct32) / sizeof(u32),
.size = sizeof(u32), .align = sizeof(u32),
.get = genregs32_get, .set = genregs32_set
.regset_get = genregs32_get, .set = genregs32_set
},
[REGSET_FP] = {
.core_note_type = NT_PRFPREG,
.n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
.size = sizeof(u32), .align = sizeof(u32),
.active = regset_fpregs_active, .get = fpregs_get, .set = fpregs_set
.active = regset_fpregs_active, .regset_get = fpregs_get, .set = fpregs_set
},
[REGSET_XFP] = {
.core_note_type = NT_PRXFPREG,
.n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
.size = sizeof(u32), .align = sizeof(u32),
.active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
.active = regset_xregset_fpregs_active, .regset_get = xfpregs_get, .set = xfpregs_set
},
[REGSET_XSTATE] = {
.core_note_type = NT_X86_XSTATE,
.size = sizeof(u64), .align = sizeof(u64),
.active = xstateregs_active, .get = xstateregs_get,
.active = xstateregs_active, .regset_get = xstateregs_get,
.set = xstateregs_set
},
[REGSET_TLS] = {
@@ -1301,13 +1272,13 @@ static struct user_regset x86_32_regsets[] __ro_after_init = {
.size = sizeof(struct user_desc),
.align = sizeof(struct user_desc),
.active = regset_tls_active,
.get = regset_tls_get, .set = regset_tls_set
.regset_get = regset_tls_get, .set = regset_tls_set
},
[REGSET_IOPERM32] = {
.core_note_type = NT_386_IOPERM,
.n = IO_BITMAP_BYTES / sizeof(u32),
.size = sizeof(u32), .align = sizeof(u32),
.active = ioperm_active, .get = ioperm_get
.active = ioperm_active, .regset_get = ioperm_get
},
};