linux/arch/powerpc/kernel/ptrace/ptrace-altivec.c
Al Viro 47e12855a9 powerpc: switch to ->regset_get()
Note: compat variant of REGSET_TM_CGPR is almost certainly wrong;
it claims to be 48*64bit, but just as compat REGSET_GPR it stores
44*32bit of (truncated) registers + 4 32bit zeros... followed by
48 more 32bit zeroes.  Might be too late to change - it's a userland
ABI, after all ;-/

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-07-27 14:31:07 -04:00

116 lines
3.0 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
#include <linux/regset.h>
#include <linux/elf.h>
#include <asm/switch_to.h>
#include "ptrace-decl.h"
/*
* Get/set all the altivec registers vr0..vr31, vscr, vrsave, in one go.
* The transfer totals 34 quadword. Quadwords 0-31 contain the
* corresponding vector registers. Quadword 32 contains the vscr as the
* last word (offset 12) within that quadword. Quadword 33 contains the
* vrsave as the first word (offset 0) within the quadword.
*
* This definition of the VMX state is compatible with the current PPC32
* ptrace interface. This allows signal handling and ptrace to use the
* same structures. This also simplifies the implementation of a bi-arch
* (combined (32- and 64-bit) gdb.
*/
int vr_active(struct task_struct *target, const struct user_regset *regset)
{
flush_altivec_to_thread(target);
return target->thread.used_vr ? regset->n : 0;
}
/*
* Regardless of transactions, 'vr_state' holds the current running
* value of all the VMX registers and 'ckvr_state' holds the last
* checkpointed value of all the VMX registers for the current
* transaction to fall back on in case it aborts.
*
* Userspace interface buffer layout:
*
* struct data {
* vector128 vr[32];
* vector128 vscr;
* vector128 vrsave;
* };
*/
int vr_get(struct task_struct *target, const struct user_regset *regset,
struct membuf to)
{
union {
elf_vrreg_t reg;
u32 word;
} vrsave;
flush_altivec_to_thread(target);
BUILD_BUG_ON(offsetof(struct thread_vr_state, vscr) !=
offsetof(struct thread_vr_state, vr[32]));
membuf_write(&to, &target->thread.vr_state, 33 * sizeof(vector128));
/*
* Copy out only the low-order word of vrsave.
*/
memset(&vrsave, 0, sizeof(vrsave));
vrsave.word = target->thread.vrsave;
return membuf_write(&to, &vrsave, sizeof(vrsave));
}
/*
* Regardless of transactions, 'vr_state' holds the current running
* value of all the VMX registers and 'ckvr_state' holds the last
* checkpointed value of all the VMX registers for the current
* transaction to fall back on in case it aborts.
*
* Userspace interface buffer layout:
*
* struct data {
* vector128 vr[32];
* vector128 vscr;
* vector128 vrsave;
* };
*/
int vr_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;
flush_altivec_to_thread(target);
BUILD_BUG_ON(offsetof(struct thread_vr_state, vscr) !=
offsetof(struct thread_vr_state, vr[32]));
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
&target->thread.vr_state, 0,
33 * sizeof(vector128));
if (!ret && count > 0) {
/*
* We use only the first word of vrsave.
*/
int start, end;
union {
elf_vrreg_t reg;
u32 word;
} vrsave;
memset(&vrsave, 0, sizeof(vrsave));
vrsave.word = target->thread.vrsave;
start = 33 * sizeof(vector128);
end = start + sizeof(vrsave);
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &vrsave,
start, end);
if (!ret)
target->thread.vrsave = vrsave.word;
}
return ret;
}