linux/arch/parisc/math-emu/driver.c
Linus Torvalds 5ad18b2e60 Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull force_sig() argument change from Eric Biederman:
 "A source of error over the years has been that force_sig has taken a
  task parameter when it is only safe to use force_sig with the current
  task.

  The force_sig function is built for delivering synchronous signals
  such as SIGSEGV where the userspace application caused a synchronous
  fault (such as a page fault) and the kernel responded with a signal.

  Because the name force_sig does not make this clear, and because the
  force_sig takes a task parameter the function force_sig has been
  abused for sending other kinds of signals over the years. Slowly those
  have been fixed when the oopses have been tracked down.

  This set of changes fixes the remaining abusers of force_sig and
  carefully rips out the task parameter from force_sig and friends
  making this kind of error almost impossible in the future"

* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (27 commits)
  signal/x86: Move tsk inside of CONFIG_MEMORY_FAILURE in do_sigbus
  signal: Remove the signal number and task parameters from force_sig_info
  signal: Factor force_sig_info_to_task out of force_sig_info
  signal: Generate the siginfo in force_sig
  signal: Move the computation of force into send_signal and correct it.
  signal: Properly set TRACE_SIGNAL_LOSE_INFO in __send_signal
  signal: Remove the task parameter from force_sig_fault
  signal: Use force_sig_fault_to_task for the two calls that don't deliver to current
  signal: Explicitly call force_sig_fault on current
  signal/unicore32: Remove tsk parameter from __do_user_fault
  signal/arm: Remove tsk parameter from __do_user_fault
  signal/arm: Remove tsk parameter from ptrace_break
  signal/nds32: Remove tsk parameter from send_sigtrap
  signal/riscv: Remove tsk parameter from do_trap
  signal/sh: Remove tsk parameter from force_sig_info_fault
  signal/um: Remove task parameter from send_sigtrap
  signal/x86: Remove task parameter from send_sigtrap
  signal: Remove task parameter from force_sig_mceerr
  signal: Remove task parameter from force_sig
  signal: Remove task parameter from force_sigsegv
  ...
2019-07-08 21:48:15 -07:00

113 lines
3.0 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Linux/PA-RISC Project (http://www.parisc-linux.org/)
*
* Floating-point emulation code
* Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org>
*/
/*
* linux/arch/math-emu/driver.c.c
*
* decodes and dispatches unimplemented FPU instructions
*
* Copyright (C) 1999, 2000 Philipp Rumpf <prumpf@tux.org>
* Copyright (C) 2001 Hewlett-Packard <bame@debian.org>
*/
#include <linux/sched/signal.h>
#include "float.h"
#include "math-emu.h"
#define fptpos 31
#define fpr1pos 10
#define extru(r,pos,len) (((r) >> (31-(pos))) & (( 1 << (len)) - 1))
#define FPUDEBUG 0
/* Format of the floating-point exception registers. */
struct exc_reg {
unsigned int exception : 6;
unsigned int ei : 26;
};
/* Macros for grabbing bits of the instruction format from the 'ei'
field above. */
/* Major opcode 0c and 0e */
#define FP0CE_UID(i) (((i) >> 6) & 3)
#define FP0CE_CLASS(i) (((i) >> 9) & 3)
#define FP0CE_SUBOP(i) (((i) >> 13) & 7)
#define FP0CE_SUBOP1(i) (((i) >> 15) & 7) /* Class 1 subopcode */
#define FP0C_FORMAT(i) (((i) >> 11) & 3)
#define FP0E_FORMAT(i) (((i) >> 11) & 1)
/* Major opcode 0c, uid 2 (performance monitoring) */
#define FPPM_SUBOP(i) (((i) >> 9) & 0x1f)
/* Major opcode 2e (fused operations). */
#define FP2E_SUBOP(i) (((i) >> 5) & 1)
#define FP2E_FORMAT(i) (((i) >> 11) & 1)
/* Major opcode 26 (FMPYSUB) */
/* Major opcode 06 (FMPYADD) */
#define FPx6_FORMAT(i) ((i) & 0x1f)
/* Flags and enable bits of the status word. */
#define FPSW_FLAGS(w) ((w) >> 27)
#define FPSW_ENABLE(w) ((w) & 0x1f)
#define FPSW_V (1<<4)
#define FPSW_Z (1<<3)
#define FPSW_O (1<<2)
#define FPSW_U (1<<1)
#define FPSW_I (1<<0)
/* Handle a floating point exception. Return zero if the faulting
instruction can be completed successfully. */
int
handle_fpe(struct pt_regs *regs)
{
extern void printbinary(unsigned long x, int nbits);
unsigned int orig_sw, sw;
int signalcode;
/* need an intermediate copy of float regs because FPU emulation
* code expects an artificial last entry which contains zero
*
* also, the passed in fr registers contain one word that defines
* the fpu type. the fpu type information is constructed
* inside the emulation code
*/
__u64 frcopy[36];
memcpy(frcopy, regs->fr, sizeof regs->fr);
frcopy[32] = 0;
memcpy(&orig_sw, frcopy, sizeof(orig_sw));
if (FPUDEBUG) {
printk(KERN_DEBUG "FP VZOUICxxxxCQCQCQCQCQCRMxxTDVZOUI ->\n ");
printbinary(orig_sw, 32);
printk(KERN_DEBUG "\n");
}
signalcode = decode_fpu(frcopy, 0x666);
/* Status word = FR0L. */
memcpy(&sw, frcopy, sizeof(sw));
if (FPUDEBUG) {
printk(KERN_DEBUG "VZOUICxxxxCQCQCQCQCQCRMxxTDVZOUI decode_fpu returns %d|0x%x\n",
signalcode >> 24, signalcode & 0xffffff);
printbinary(sw, 32);
printk(KERN_DEBUG "\n");
}
memcpy(regs->fr, frcopy, sizeof regs->fr);
if (signalcode != 0) {
force_sig_fault(signalcode >> 24, signalcode & 0xffffff,
(void __user *) regs->iaoq[0]);
return -1;
}
return signalcode ? -1 : 0;
}