mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-19 19:56:45 +07:00
f56141e3e2
If an attacker can cause a controlled kernel stack overflow, overwriting the restart block is a very juicy exploit target. This is because the restart_block is held in the same memory allocation as the kernel stack. Moving the restart block to struct task_struct prevents this exploit by making the restart_block harder to locate. Note that there are other fields in thread_info that are also easy targets, at least on some architectures. It's also a decent simplification, since the restart code is more or less identical on all architectures. [james.hogan@imgtec.com: metag: align thread_info::supervisor_stack] Signed-off-by: Andy Lutomirski <luto@amacapital.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: David Miller <davem@davemloft.net> Acked-by: Richard Weinberger <richard@nod.at> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Steven Miao <realmz6@gmail.com> Cc: Mark Salter <msalter@redhat.com> Cc: Aurelien Jacquiot <a-jacquiot@ti.com> Cc: Mikael Starvik <starvik@axis.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: David Howells <dhowells@redhat.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Chen Liqin <liqin.linux@gmail.com> Cc: Lennox Wu <lennox.wu@gmail.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
134 lines
4.2 KiB
C
134 lines
4.2 KiB
C
/*
|
|
* Thread support for the Hexagon architecture
|
|
*
|
|
* Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 and
|
|
* only version 2 as published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
|
|
* 02110-1301, USA.
|
|
*/
|
|
|
|
#ifndef _ASM_THREAD_INFO_H
|
|
#define _ASM_THREAD_INFO_H
|
|
|
|
#ifdef __KERNEL__
|
|
|
|
#ifndef __ASSEMBLY__
|
|
#include <asm/processor.h>
|
|
#include <asm/registers.h>
|
|
#include <asm/page.h>
|
|
#endif
|
|
|
|
#define THREAD_SHIFT 12
|
|
#define THREAD_SIZE (1<<THREAD_SHIFT)
|
|
#define THREAD_SIZE_ORDER (THREAD_SHIFT - PAGE_SHIFT)
|
|
|
|
#ifndef __ASSEMBLY__
|
|
|
|
typedef struct {
|
|
unsigned long seg;
|
|
} mm_segment_t;
|
|
|
|
/*
|
|
* This is union'd with the "bottom" of the kernel stack.
|
|
* It keeps track of thread info which is handy for routines
|
|
* to access quickly.
|
|
*/
|
|
|
|
struct thread_info {
|
|
struct task_struct *task; /* main task structure */
|
|
struct exec_domain *exec_domain; /* execution domain */
|
|
unsigned long flags; /* low level flags */
|
|
__u32 cpu; /* current cpu */
|
|
int preempt_count; /* 0=>preemptible,<0=>BUG */
|
|
mm_segment_t addr_limit; /* segmentation sux */
|
|
/*
|
|
* used for syscalls somehow;
|
|
* seems to have a function pointer and four arguments
|
|
*/
|
|
/* Points to the current pt_regs frame */
|
|
struct pt_regs *regs;
|
|
/*
|
|
* saved kernel sp at switch_to time;
|
|
* not sure if this is used (it's not in the VM model it seems;
|
|
* see thread_struct)
|
|
*/
|
|
unsigned long sp;
|
|
};
|
|
|
|
#else /* !__ASSEMBLY__ */
|
|
|
|
#include <asm/asm-offsets.h>
|
|
|
|
#endif /* __ASSEMBLY__ */
|
|
|
|
#ifndef __ASSEMBLY__
|
|
|
|
#define INIT_THREAD_INFO(tsk) \
|
|
{ \
|
|
.task = &tsk, \
|
|
.exec_domain = &default_exec_domain, \
|
|
.flags = 0, \
|
|
.cpu = 0, \
|
|
.preempt_count = 1, \
|
|
.addr_limit = KERNEL_DS, \
|
|
.sp = 0, \
|
|
.regs = NULL, \
|
|
}
|
|
|
|
#define init_thread_info (init_thread_union.thread_info)
|
|
#define init_stack (init_thread_union.stack)
|
|
|
|
/* Tacky preprocessor trickery */
|
|
#define qqstr(s) qstr(s)
|
|
#define qstr(s) #s
|
|
#define QUOTED_THREADINFO_REG qqstr(THREADINFO_REG)
|
|
|
|
register struct thread_info *__current_thread_info asm(QUOTED_THREADINFO_REG);
|
|
#define current_thread_info() __current_thread_info
|
|
|
|
#endif /* __ASSEMBLY__ */
|
|
|
|
/*
|
|
* thread information flags
|
|
* - these are process state flags that various assembly files
|
|
* may need to access
|
|
* - pending work-to-be-done flags are in LSW
|
|
* - other flags in MSW
|
|
*/
|
|
|
|
#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
|
|
#define TIF_NOTIFY_RESUME 1 /* resumption notification requested */
|
|
#define TIF_SIGPENDING 2 /* signal pending */
|
|
#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
|
|
#define TIF_SINGLESTEP 4 /* restore ss @ return to usr mode */
|
|
#define TIF_RESTORE_SIGMASK 6 /* restore sig mask in do_signal() */
|
|
/* true if poll_idle() is polling TIF_NEED_RESCHED */
|
|
#define TIF_MEMDIE 17 /* OOM killer killed process */
|
|
|
|
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
|
|
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
|
|
#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
|
|
#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
|
|
#define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP)
|
|
|
|
/* work to do on interrupt/exception return - All but TIF_SYSCALL_TRACE */
|
|
#define _TIF_WORK_MASK (0x0000FFFF & ~_TIF_SYSCALL_TRACE)
|
|
|
|
/* work to do on any return to u-space */
|
|
#define _TIF_ALLWORK_MASK 0x0000FFFF
|
|
|
|
#endif /* __KERNEL__ */
|
|
|
|
#endif
|