mirror of
https://github.com/torvalds/linux.git
synced 2024-12-06 02:52:22 +00:00
0163005374
Commit 8ba62d3794
("task_work: Call tracehook_notify_signal from
get_signal on all architectures") adjust arch_do_signal_or_restart() for
all architectures. LoongArch hasn't been upstream yet at that time and
can be still built successfully without adjustment because this function
has a weak version with the correct prototype. It is obviously that we
should convert LoongArch to use new API, otherwise some signal handlings
will be lost.
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
567 lines
13 KiB
C
567 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0+
|
|
/*
|
|
* Author: Hanlu Li <lihanlu@loongson.cn>
|
|
* Huacai Chen <chenhuacai@loongson.cn>
|
|
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
|
|
*
|
|
* Derived from MIPS:
|
|
* Copyright (C) 1991, 1992 Linus Torvalds
|
|
* Copyright (C) 1994 - 2000 Ralf Baechle
|
|
* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
|
|
* Copyright (C) 2014, Imagination Technologies Ltd.
|
|
*/
|
|
#include <linux/audit.h>
|
|
#include <linux/cache.h>
|
|
#include <linux/context_tracking.h>
|
|
#include <linux/irqflags.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/personality.h>
|
|
#include <linux/smp.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/signal.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/wait.h>
|
|
#include <linux/ptrace.h>
|
|
#include <linux/unistd.h>
|
|
#include <linux/compiler.h>
|
|
#include <linux/syscalls.h>
|
|
#include <linux/uaccess.h>
|
|
|
|
#include <asm/asm.h>
|
|
#include <asm/cacheflush.h>
|
|
#include <asm/cpu-features.h>
|
|
#include <asm/fpu.h>
|
|
#include <asm/ucontext.h>
|
|
#include <asm/vdso.h>
|
|
|
|
#ifdef DEBUG_SIG
|
|
# define DEBUGP(fmt, args...) printk("%s: " fmt, __func__, ##args)
|
|
#else
|
|
# define DEBUGP(fmt, args...)
|
|
#endif
|
|
|
|
/* Make sure we will not lose FPU ownership */
|
|
#define lock_fpu_owner() ({ preempt_disable(); pagefault_disable(); })
|
|
#define unlock_fpu_owner() ({ pagefault_enable(); preempt_enable(); })
|
|
|
|
/* Assembly functions to move context to/from the FPU */
|
|
extern asmlinkage int
|
|
_save_fp_context(void __user *fpregs, void __user *fcc, void __user *csr);
|
|
extern asmlinkage int
|
|
_restore_fp_context(void __user *fpregs, void __user *fcc, void __user *csr);
|
|
|
|
struct rt_sigframe {
|
|
struct siginfo rs_info;
|
|
struct ucontext rs_uctx;
|
|
};
|
|
|
|
struct _ctx_layout {
|
|
struct sctx_info *addr;
|
|
unsigned int size;
|
|
};
|
|
|
|
struct extctx_layout {
|
|
unsigned long size;
|
|
unsigned int flags;
|
|
struct _ctx_layout fpu;
|
|
struct _ctx_layout end;
|
|
};
|
|
|
|
static void __user *get_ctx_through_ctxinfo(struct sctx_info *info)
|
|
{
|
|
return (void __user *)((char *)info + sizeof(struct sctx_info));
|
|
}
|
|
|
|
/*
|
|
* Thread saved context copy to/from a signal context presumed to be on the
|
|
* user stack, and therefore accessed with appropriate macros from uaccess.h.
|
|
*/
|
|
static int copy_fpu_to_sigcontext(struct fpu_context __user *ctx)
|
|
{
|
|
int i;
|
|
int err = 0;
|
|
uint64_t __user *regs = (uint64_t *)&ctx->regs;
|
|
uint64_t __user *fcc = &ctx->fcc;
|
|
uint32_t __user *fcsr = &ctx->fcsr;
|
|
|
|
for (i = 0; i < NUM_FPU_REGS; i++) {
|
|
err |=
|
|
__put_user(get_fpr64(¤t->thread.fpu.fpr[i], 0),
|
|
®s[i]);
|
|
}
|
|
err |= __put_user(current->thread.fpu.fcc, fcc);
|
|
err |= __put_user(current->thread.fpu.fcsr, fcsr);
|
|
|
|
return err;
|
|
}
|
|
|
|
static int copy_fpu_from_sigcontext(struct fpu_context __user *ctx)
|
|
{
|
|
int i;
|
|
int err = 0;
|
|
u64 fpr_val;
|
|
uint64_t __user *regs = (uint64_t *)&ctx->regs;
|
|
uint64_t __user *fcc = &ctx->fcc;
|
|
uint32_t __user *fcsr = &ctx->fcsr;
|
|
|
|
for (i = 0; i < NUM_FPU_REGS; i++) {
|
|
err |= __get_user(fpr_val, ®s[i]);
|
|
set_fpr64(¤t->thread.fpu.fpr[i], 0, fpr_val);
|
|
}
|
|
err |= __get_user(current->thread.fpu.fcc, fcc);
|
|
err |= __get_user(current->thread.fpu.fcsr, fcsr);
|
|
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Wrappers for the assembly _{save,restore}_fp_context functions.
|
|
*/
|
|
static int save_hw_fpu_context(struct fpu_context __user *ctx)
|
|
{
|
|
uint64_t __user *regs = (uint64_t *)&ctx->regs;
|
|
uint64_t __user *fcc = &ctx->fcc;
|
|
uint32_t __user *fcsr = &ctx->fcsr;
|
|
|
|
return _save_fp_context(regs, fcc, fcsr);
|
|
}
|
|
|
|
static int restore_hw_fpu_context(struct fpu_context __user *ctx)
|
|
{
|
|
uint64_t __user *regs = (uint64_t *)&ctx->regs;
|
|
uint64_t __user *fcc = &ctx->fcc;
|
|
uint32_t __user *fcsr = &ctx->fcsr;
|
|
|
|
return _restore_fp_context(regs, fcc, fcsr);
|
|
}
|
|
|
|
static int fcsr_pending(unsigned int __user *fcsr)
|
|
{
|
|
int err, sig = 0;
|
|
unsigned int csr, enabled;
|
|
|
|
err = __get_user(csr, fcsr);
|
|
enabled = ((csr & FPU_CSR_ALL_E) << 24);
|
|
/*
|
|
* If the signal handler set some FPU exceptions, clear it and
|
|
* send SIGFPE.
|
|
*/
|
|
if (csr & enabled) {
|
|
csr &= ~enabled;
|
|
err |= __put_user(csr, fcsr);
|
|
sig = SIGFPE;
|
|
}
|
|
return err ?: sig;
|
|
}
|
|
|
|
/*
|
|
* Helper routines
|
|
*/
|
|
static int protected_save_fpu_context(struct extctx_layout *extctx)
|
|
{
|
|
int err = 0;
|
|
struct sctx_info __user *info = extctx->fpu.addr;
|
|
struct fpu_context __user *fpu_ctx = (struct fpu_context *)get_ctx_through_ctxinfo(info);
|
|
uint64_t __user *regs = (uint64_t *)&fpu_ctx->regs;
|
|
uint64_t __user *fcc = &fpu_ctx->fcc;
|
|
uint32_t __user *fcsr = &fpu_ctx->fcsr;
|
|
|
|
while (1) {
|
|
lock_fpu_owner();
|
|
if (is_fpu_owner())
|
|
err = save_hw_fpu_context(fpu_ctx);
|
|
else
|
|
err = copy_fpu_to_sigcontext(fpu_ctx);
|
|
unlock_fpu_owner();
|
|
|
|
err |= __put_user(FPU_CTX_MAGIC, &info->magic);
|
|
err |= __put_user(extctx->fpu.size, &info->size);
|
|
|
|
if (likely(!err))
|
|
break;
|
|
/* Touch the FPU context and try again */
|
|
err = __put_user(0, ®s[0]) |
|
|
__put_user(0, ®s[31]) |
|
|
__put_user(0, fcc) |
|
|
__put_user(0, fcsr);
|
|
if (err)
|
|
return err; /* really bad sigcontext */
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static int protected_restore_fpu_context(struct extctx_layout *extctx)
|
|
{
|
|
int err = 0, sig = 0, tmp __maybe_unused;
|
|
struct sctx_info __user *info = extctx->fpu.addr;
|
|
struct fpu_context __user *fpu_ctx = (struct fpu_context *)get_ctx_through_ctxinfo(info);
|
|
uint64_t __user *regs = (uint64_t *)&fpu_ctx->regs;
|
|
uint64_t __user *fcc = &fpu_ctx->fcc;
|
|
uint32_t __user *fcsr = &fpu_ctx->fcsr;
|
|
|
|
err = sig = fcsr_pending(fcsr);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
while (1) {
|
|
lock_fpu_owner();
|
|
if (is_fpu_owner())
|
|
err = restore_hw_fpu_context(fpu_ctx);
|
|
else
|
|
err = copy_fpu_from_sigcontext(fpu_ctx);
|
|
unlock_fpu_owner();
|
|
|
|
if (likely(!err))
|
|
break;
|
|
/* Touch the FPU context and try again */
|
|
err = __get_user(tmp, ®s[0]) |
|
|
__get_user(tmp, ®s[31]) |
|
|
__get_user(tmp, fcc) |
|
|
__get_user(tmp, fcsr);
|
|
if (err)
|
|
break; /* really bad sigcontext */
|
|
}
|
|
|
|
return err ?: sig;
|
|
}
|
|
|
|
static int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
|
|
struct extctx_layout *extctx)
|
|
{
|
|
int i, err = 0;
|
|
struct sctx_info __user *info;
|
|
|
|
err |= __put_user(regs->csr_era, &sc->sc_pc);
|
|
err |= __put_user(extctx->flags, &sc->sc_flags);
|
|
|
|
err |= __put_user(0, &sc->sc_regs[0]);
|
|
for (i = 1; i < 32; i++)
|
|
err |= __put_user(regs->regs[i], &sc->sc_regs[i]);
|
|
|
|
if (extctx->fpu.addr)
|
|
err |= protected_save_fpu_context(extctx);
|
|
|
|
/* Set the "end" magic */
|
|
info = (struct sctx_info *)extctx->end.addr;
|
|
err |= __put_user(0, &info->magic);
|
|
err |= __put_user(0, &info->size);
|
|
|
|
return err;
|
|
}
|
|
|
|
static int parse_extcontext(struct sigcontext __user *sc, struct extctx_layout *extctx)
|
|
{
|
|
int err = 0;
|
|
unsigned int magic, size;
|
|
struct sctx_info __user *info = (struct sctx_info __user *)&sc->sc_extcontext;
|
|
|
|
while(1) {
|
|
err |= __get_user(magic, &info->magic);
|
|
err |= __get_user(size, &info->size);
|
|
if (err)
|
|
return err;
|
|
|
|
switch (magic) {
|
|
case 0: /* END */
|
|
goto done;
|
|
|
|
case FPU_CTX_MAGIC:
|
|
if (size < (sizeof(struct sctx_info) +
|
|
sizeof(struct fpu_context)))
|
|
goto invalid;
|
|
extctx->fpu.addr = info;
|
|
break;
|
|
|
|
default:
|
|
goto invalid;
|
|
}
|
|
|
|
info = (struct sctx_info *)((char *)info + size);
|
|
}
|
|
|
|
done:
|
|
return 0;
|
|
|
|
invalid:
|
|
return -EINVAL;
|
|
}
|
|
|
|
static int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
|
|
{
|
|
int i, err = 0;
|
|
struct extctx_layout extctx;
|
|
|
|
memset(&extctx, 0, sizeof(struct extctx_layout));
|
|
|
|
err = __get_user(extctx.flags, &sc->sc_flags);
|
|
if (err)
|
|
goto bad;
|
|
|
|
err = parse_extcontext(sc, &extctx);
|
|
if (err)
|
|
goto bad;
|
|
|
|
conditional_used_math(extctx.flags & SC_USED_FP);
|
|
|
|
/*
|
|
* The signal handler may have used FPU; give it up if the program
|
|
* doesn't want it following sigreturn.
|
|
*/
|
|
if (!(extctx.flags & SC_USED_FP))
|
|
lose_fpu(0);
|
|
|
|
/* Always make any pending restarted system calls return -EINTR */
|
|
current->restart_block.fn = do_no_restart_syscall;
|
|
|
|
err |= __get_user(regs->csr_era, &sc->sc_pc);
|
|
for (i = 1; i < 32; i++)
|
|
err |= __get_user(regs->regs[i], &sc->sc_regs[i]);
|
|
|
|
if (extctx.fpu.addr)
|
|
err |= protected_restore_fpu_context(&extctx);
|
|
|
|
bad:
|
|
return err;
|
|
}
|
|
|
|
static unsigned int handle_flags(void)
|
|
{
|
|
unsigned int flags = 0;
|
|
|
|
flags = used_math() ? SC_USED_FP : 0;
|
|
|
|
switch (current->thread.error_code) {
|
|
case 1:
|
|
flags |= SC_ADDRERR_RD;
|
|
break;
|
|
case 2:
|
|
flags |= SC_ADDRERR_WR;
|
|
break;
|
|
}
|
|
|
|
return flags;
|
|
}
|
|
|
|
static unsigned long extframe_alloc(struct extctx_layout *extctx,
|
|
struct _ctx_layout *layout,
|
|
size_t size, unsigned int align, unsigned long base)
|
|
{
|
|
unsigned long new_base = base - size;
|
|
|
|
new_base = round_down(new_base, (align < 16 ? 16 : align));
|
|
new_base -= sizeof(struct sctx_info);
|
|
|
|
layout->addr = (void *)new_base;
|
|
layout->size = (unsigned int)(base - new_base);
|
|
extctx->size += layout->size;
|
|
|
|
return new_base;
|
|
}
|
|
|
|
static unsigned long setup_extcontext(struct extctx_layout *extctx, unsigned long sp)
|
|
{
|
|
unsigned long new_sp = sp;
|
|
|
|
memset(extctx, 0, sizeof(struct extctx_layout));
|
|
|
|
extctx->flags = handle_flags();
|
|
|
|
/* Grow down, alloc "end" context info first. */
|
|
new_sp -= sizeof(struct sctx_info);
|
|
extctx->end.addr = (void *)new_sp;
|
|
extctx->end.size = (unsigned int)sizeof(struct sctx_info);
|
|
extctx->size += extctx->end.size;
|
|
|
|
if (extctx->flags & SC_USED_FP) {
|
|
if (cpu_has_fpu)
|
|
new_sp = extframe_alloc(extctx, &extctx->fpu,
|
|
sizeof(struct fpu_context), FPU_CTX_ALIGN, new_sp);
|
|
}
|
|
|
|
return new_sp;
|
|
}
|
|
|
|
void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
|
|
struct extctx_layout *extctx)
|
|
{
|
|
unsigned long sp;
|
|
|
|
/* Default to using normal stack */
|
|
sp = regs->regs[3];
|
|
|
|
/*
|
|
* If we are on the alternate signal stack and would overflow it, don't.
|
|
* Return an always-bogus address instead so we will die with SIGSEGV.
|
|
*/
|
|
if (on_sig_stack(sp) &&
|
|
!likely(on_sig_stack(sp - sizeof(struct rt_sigframe))))
|
|
return (void __user __force *)(-1UL);
|
|
|
|
sp = sigsp(sp, ksig);
|
|
sp = round_down(sp, 16);
|
|
sp = setup_extcontext(extctx, sp);
|
|
sp -= sizeof(struct rt_sigframe);
|
|
|
|
if (!IS_ALIGNED(sp, 16))
|
|
BUG();
|
|
|
|
return (void __user *)sp;
|
|
}
|
|
|
|
/*
|
|
* Atomically swap in the new signal mask, and wait for a signal.
|
|
*/
|
|
|
|
asmlinkage long sys_rt_sigreturn(void)
|
|
{
|
|
int sig;
|
|
sigset_t set;
|
|
struct pt_regs *regs;
|
|
struct rt_sigframe __user *frame;
|
|
|
|
regs = current_pt_regs();
|
|
frame = (struct rt_sigframe __user *)regs->regs[3];
|
|
if (!access_ok(frame, sizeof(*frame)))
|
|
goto badframe;
|
|
if (__copy_from_user(&set, &frame->rs_uctx.uc_sigmask, sizeof(set)))
|
|
goto badframe;
|
|
|
|
set_current_blocked(&set);
|
|
|
|
sig = restore_sigcontext(regs, &frame->rs_uctx.uc_mcontext);
|
|
if (sig < 0)
|
|
goto badframe;
|
|
else if (sig)
|
|
force_sig(sig);
|
|
|
|
regs->regs[0] = 0; /* No syscall restarting */
|
|
if (restore_altstack(&frame->rs_uctx.uc_stack))
|
|
goto badframe;
|
|
|
|
return regs->regs[4];
|
|
|
|
badframe:
|
|
force_sig(SIGSEGV);
|
|
return 0;
|
|
}
|
|
|
|
static int setup_rt_frame(void *sig_return, struct ksignal *ksig,
|
|
struct pt_regs *regs, sigset_t *set)
|
|
{
|
|
int err = 0;
|
|
struct extctx_layout extctx;
|
|
struct rt_sigframe __user *frame;
|
|
|
|
frame = get_sigframe(ksig, regs, &extctx);
|
|
if (!access_ok(frame, sizeof(*frame) + extctx.size))
|
|
return -EFAULT;
|
|
|
|
/* Create siginfo. */
|
|
err |= copy_siginfo_to_user(&frame->rs_info, &ksig->info);
|
|
|
|
/* Create the ucontext. */
|
|
err |= __put_user(0, &frame->rs_uctx.uc_flags);
|
|
err |= __put_user(NULL, &frame->rs_uctx.uc_link);
|
|
err |= __save_altstack(&frame->rs_uctx.uc_stack, regs->regs[3]);
|
|
err |= setup_sigcontext(regs, &frame->rs_uctx.uc_mcontext, &extctx);
|
|
err |= __copy_to_user(&frame->rs_uctx.uc_sigmask, set, sizeof(*set));
|
|
|
|
if (err)
|
|
return -EFAULT;
|
|
|
|
/*
|
|
* Arguments to signal handler:
|
|
*
|
|
* a0 = signal number
|
|
* a1 = pointer to siginfo
|
|
* a2 = pointer to ucontext
|
|
*
|
|
* c0_era point to the signal handler, $r3 (sp) points to
|
|
* the struct rt_sigframe.
|
|
*/
|
|
regs->regs[4] = ksig->sig;
|
|
regs->regs[5] = (unsigned long) &frame->rs_info;
|
|
regs->regs[6] = (unsigned long) &frame->rs_uctx;
|
|
regs->regs[3] = (unsigned long) frame;
|
|
regs->regs[1] = (unsigned long) sig_return;
|
|
regs->csr_era = (unsigned long) ksig->ka.sa.sa_handler;
|
|
|
|
DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
|
|
current->comm, current->pid,
|
|
frame, regs->csr_era, regs->regs[1]);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
|
|
{
|
|
int ret;
|
|
sigset_t *oldset = sigmask_to_save();
|
|
void *vdso = current->mm->context.vdso;
|
|
|
|
/* Are we from a system call? */
|
|
if (regs->regs[0]) {
|
|
switch (regs->regs[4]) {
|
|
case -ERESTART_RESTARTBLOCK:
|
|
case -ERESTARTNOHAND:
|
|
regs->regs[4] = -EINTR;
|
|
break;
|
|
case -ERESTARTSYS:
|
|
if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
|
|
regs->regs[4] = -EINTR;
|
|
break;
|
|
}
|
|
fallthrough;
|
|
case -ERESTARTNOINTR:
|
|
regs->regs[4] = regs->orig_a0;
|
|
regs->csr_era -= 4;
|
|
}
|
|
|
|
regs->regs[0] = 0; /* Don't deal with this again. */
|
|
}
|
|
|
|
rseq_signal_deliver(ksig, regs);
|
|
|
|
ret = setup_rt_frame(vdso + current->thread.vdso->offset_sigreturn, ksig, regs, oldset);
|
|
|
|
signal_setup_done(ret, ksig, 0);
|
|
}
|
|
|
|
void arch_do_signal_or_restart(struct pt_regs *regs)
|
|
{
|
|
struct ksignal ksig;
|
|
|
|
if (get_signal(&ksig)) {
|
|
/* Whee! Actually deliver the signal. */
|
|
handle_signal(&ksig, regs);
|
|
return;
|
|
}
|
|
|
|
/* Are we from a system call? */
|
|
if (regs->regs[0]) {
|
|
switch (regs->regs[4]) {
|
|
case -ERESTARTNOHAND:
|
|
case -ERESTARTSYS:
|
|
case -ERESTARTNOINTR:
|
|
regs->regs[4] = regs->orig_a0;
|
|
regs->csr_era -= 4;
|
|
break;
|
|
|
|
case -ERESTART_RESTARTBLOCK:
|
|
regs->regs[4] = regs->orig_a0;
|
|
regs->regs[11] = __NR_restart_syscall;
|
|
regs->csr_era -= 4;
|
|
break;
|
|
}
|
|
regs->regs[0] = 0; /* Don't deal with this again. */
|
|
}
|
|
|
|
/*
|
|
* If there's no signal to deliver, we just put the saved sigmask
|
|
* back
|
|
*/
|
|
restore_saved_sigmask();
|
|
}
|