linux/arch/mips/include/uapi/asm/sigcontext.h
Paul Burton 16f77de82f Revert "MIPS: Save/restore MSA context around signals"
This reverts commit eec43a224c "MIPS: Save/restore MSA context around
signals" and the MSA parts of ca750649e0 "MIPS: kernel: signal:
Prevent save/restore FPU context in user memory" (the restore path of
which appears incorrect anyway...).

The reverted patch took care not to break compatibility with userland
users of struct sigcontext, but inadvertantly changed the offset of the
uc_sigmask field of struct ucontext. Thus Linux v3.15 breaks the
userland ABI. The MSA context will need to be saved via some other
opt-in mechanism, but for now revert the change to reduce the fallout.

This will have minimal impact upon use of MSA since the only supported
CPU which includes it (the P5600) is 32-bit and therefore requires that
the experimental CONFIG_MIPS_O32_FP64_SUPPORT Kconfig option be selected
before the kernel will set FR=1 for a task, a requirement for MSA use.
Thus the users of MSA are limited to known small groups of people & this
patch won't be breaking any previously working MSA-using userland
outside of experimental settings.

[ralf@linux-mips.org: Fixed rejects.]

Cc: stable@vger.kernel.org
Reported-by: Joseph S. Myers <joseph@codesourcery.com>
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7107/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-06-26 10:48:18 +01:00

79 lines
2.1 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1996, 1997, 1999 by Ralf Baechle
* Copyright (C) 1999 Silicon Graphics, Inc.
*/
#ifndef _UAPI_ASM_SIGCONTEXT_H
#define _UAPI_ASM_SIGCONTEXT_H
#include <linux/types.h>
#include <asm/sgidefs.h>
#if _MIPS_SIM == _MIPS_SIM_ABI32
/*
* Keep this struct definition in sync with the sigcontext fragment
* in arch/mips/tools/offset.c
*/
struct sigcontext {
unsigned int sc_regmask; /* Unused */
unsigned int sc_status; /* Unused */
unsigned long long sc_pc;
unsigned long long sc_regs[32];
unsigned long long sc_fpregs[32];
unsigned int sc_acx; /* Was sc_ownedfp */
unsigned int sc_fpc_csr;
unsigned int sc_fpc_eir; /* Unused */
unsigned int sc_used_math;
unsigned int sc_dsp; /* dsp status, was sc_ssflags */
unsigned long long sc_mdhi;
unsigned long long sc_mdlo;
unsigned long sc_hi1; /* Was sc_cause */
unsigned long sc_lo1; /* Was sc_badvaddr */
unsigned long sc_hi2; /* Was sc_sigset[4] */
unsigned long sc_lo2;
unsigned long sc_hi3;
unsigned long sc_lo3;
};
#endif /* _MIPS_SIM == _MIPS_SIM_ABI32 */
#if _MIPS_SIM == _MIPS_SIM_ABI64 || _MIPS_SIM == _MIPS_SIM_NABI32
#include <linux/posix_types.h>
/*
* Keep this struct definition in sync with the sigcontext fragment
* in arch/mips/tools/offset.c
*
* Warning: this structure illdefined with sc_badvaddr being just an unsigned
* int so it was changed to unsigned long in 2.6.0-test1. This may break
* binary compatibility - no prisoners.
* DSP ASE in 2.6.12-rc4. Turn sc_mdhi and sc_mdlo into an array of four
* entries, add sc_dsp and sc_reserved for padding. No prisoners.
*/
struct sigcontext {
__u64 sc_regs[32];
__u64 sc_fpregs[32];
__u64 sc_mdhi;
__u64 sc_hi1;
__u64 sc_hi2;
__u64 sc_hi3;
__u64 sc_mdlo;
__u64 sc_lo1;
__u64 sc_lo2;
__u64 sc_lo3;
__u64 sc_pc;
__u32 sc_fpc_csr;
__u32 sc_used_math;
__u32 sc_dsp;
__u32 sc_reserved;
};
#endif /* _MIPS_SIM == _MIPS_SIM_ABI64 || _MIPS_SIM == _MIPS_SIM_NABI32 */
#endif /* _UAPI_ASM_SIGCONTEXT_H */