linux.git/arch/mips/include/asm/syscall.h, branch v5.1

syscalls: Remove start and number from syscall_get_arguments() args

2019-04-05T13:26:43+00:00

At Linux Plumbers, Andy Lutomirski approached me and pointed out that the
function call syscall_get_arguments() implemented in x86 was horribly
written and not optimized for the standard case of passing in 0 and 6 for
the starting index and the number of system calls to get. When looking at
all the users of this function, I discovered that all instances pass in only
0 and 6 for these arguments. Instead of having this function handle
different cases that are never used, simply rewrite it to return the first 6
arguments of a system call.

This should help out the performance of tracing system calls by ptrace,
ftrace and perf.

Link: http://lkml.kernel.org/r/20161107213233.754809394@goodmis.org

Cc: Oleg Nesterov 
Cc: Kees Cook 
Cc: Andy Lutomirski 
Cc: Dominik Brodowski 
Cc: Dave Martin 
Cc: "Dmitry V. Levin" 
Cc: x86@kernel.org
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: uclinux-h8-devel@lists.sourceforge.jp
Cc: linux-hexagon@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-mips@vger.kernel.org
Cc: nios2-dev@lists.rocketboards.org
Cc: openrisc@lists.librecores.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Cc: linux-um@lists.infradead.org
Cc: linux-xtensa@linux-xtensa.org
Cc: linux-arch@vger.kernel.org
Acked-by: Paul Burton  # MIPS parts
Acked-by: Max Filippov  # For xtensa changes
Acked-by: Will Deacon  # For the arm64 bits
Reviewed-by: Thomas Gleixner  # for x86
Reviewed-by: Dmitry V. Levin 
Reported-by: Andy Lutomirski 
Signed-off-by: Steven Rostedt (VMware)

mips: fix mips_get_syscall_arg o32 check

2018-11-21T19:21:52+00:00

When checking for TIF_32BIT_REGS flag, mips_get_syscall_arg() should
use the task specified as its argument instead of the current task.

This potentially affects all syscall_get_arguments() users
who specify tasks different from the current.

Fixes: c0ff3c53d4f99 ("MIPS: Enable HAVE_ARCH_TRACEHOOK.")
Signed-off-by: Dmitry V. Levin 
Signed-off-by: Paul Burton 
Patchwork: https://patchwork.linux-mips.org/patch/21185/
Cc: Elvira Khabirova 
Cc: Ralf Baechle 
Cc: James Hogan 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org # v3.13+

MIPS/ptrace: Update syscall nr on register changes

2017-11-09T15:13:58+00:00

Update the thread_info::syscall field when registers are modified via
ptrace to change or cancel the system call being entered.

This is important to allow seccomp and the syscall entry and exit trace
events to observe the new syscall number changed by the normal ptrace
hook or seccomp. That includes allowing seccomp's recheck of the system
call number after SECCOMP_RET_TRACE to notice if the syscall is changed
to a denied one, which happens in seccomp since commit ce6526e8afa4
("seccomp: recheck the syscall after RET_TRACE") in v4.8.

In the process of doing this, the logic to determine whether an indirect
system call is in progress (i.e. the O32 ABI's syscall()) is abstracted
into mips_syscall_is_indirect(), and a new mips_syscall_update_nr() is
used to update the thread_info::syscall based on the register state.

The following ptrace operations are updated:
 - PTRACE_SETREGS (ptrace_setregs()).
 - PTRACE_SETREGSET with NT_PRSTATUS (gpr32_set() and gpr64_set()).
 - PTRACE_POKEUSR with 2/v0 or 4/a0 for indirect syscall
   ([compat_]arch_ptrace()).

Fixes: c2d9f1775731 ("MIPS: Fix syscall_get_nr for the syscall exit tracing.")
Signed-off-by: James Hogan 
Cc: Ralf Baechle 
Cc: Lars Persson 
Cc: Oleg Nesterov 
Cc: Kees Cook 
Cc: Andy Lutomirski 
Cc: Will Drewry 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16995/

MIPS: Correct forced syscall errors

2017-07-11T12:13:06+00:00

When the system call return value is forced to be an error (for example
due to SECCOMP_RET_ERRNO), syscall_set_return_value() puts the error
code in the return register $v0 and -1 in the error register $a3.

However normally executed system calls put 1 in the error register
rather than -1, so fix syscall_set_return_value() to be consistent with
that.

I don't anticipate that anything would have been broken by this, since
the most natural way to check the error register on MIPS would be a
conditional branch if error register is [not] equal to zero (bnez or
beqz).

Fixes: 1d7bf993e073 ("MIPS: ftrace: Add support for syscall tracepoints.")
Signed-off-by: James Hogan 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16652/
Signed-off-by: Ralf Baechle

tree-wide: replace config_enabled() with IS_ENABLED()

2016-08-04T12:50:07+00:00

The use of config_enabled() against config options is ambiguous.  In
practical terms, config_enabled() is equivalent to IS_BUILTIN(), but the
author might have used it for the meaning of IS_ENABLED().  Using
IS_ENABLED(), IS_BUILTIN(), IS_MODULE() etc.  makes the intention
clearer.

This commit replaces config_enabled() with IS_ENABLED() where possible.
This commit is only touching bool config options.

I noticed two cases where config_enabled() is used against a tristate
option:

 - config_enabled(CONFIG_HWMON)
  [ drivers/net/wireless/ath/ath10k/thermal.c ]

 - config_enabled(CONFIG_BACKLIGHT_CLASS_DEVICE)
  [ drivers/gpu/drm/gma500/opregion.c ]

I did not touch them because they should be converted to IS_BUILTIN()
in order to keep the logic, but I was not sure it was the authors'
intention.

Link: http://lkml.kernel.org/r/1465215656-20569-1-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada 
Acked-by: Kees Cook 
Cc: Stas Sergeev 
Cc: Matt Redfearn 
Cc: Joshua Kinard 
Cc: Jiri Slaby 
Cc: Bjorn Helgaas 
Cc: Borislav Petkov 
Cc: Markos Chandras 
Cc: "Dmitry V. Levin" 
Cc: yu-cheng yu 
Cc: James Hogan 
Cc: Brian Gerst 
Cc: Johannes Berg 
Cc: Peter Zijlstra 
Cc: Al Viro 
Cc: Will Drewry 
Cc: Nikolay Martynov 
Cc: Huacai Chen 
Cc: "H. Peter Anvin" 
Cc: Thomas Gleixner 
Cc: Daniel Borkmann 
Cc: Leonid Yegoshin 
Cc: Rafal Milecki 
Cc: James Cowgill 
Cc: Greg Kroah-Hartman 
Cc: Ralf Baechle 
Cc: Alex Smith 
Cc: Adam Buchbinder 
Cc: Qais Yousef 
Cc: Jiang Liu 
Cc: Mikko Rapeli 
Cc: Paul Gortmaker 
Cc: Denys Vlasenko 
Cc: Brian Norris 
Cc: Hidehiro Kawai 
Cc: "Luis R. Rodriguez" 
Cc: Andy Lutomirski 
Cc: Ingo Molnar 
Cc: Dave Hansen 
Cc: "Kirill A. Shutemov" 
Cc: Roland McGrath 
Cc: Paul Burton 
Cc: Kalle Valo 
Cc: Viresh Kumar 
Cc: Tony Wu 
Cc: Huaitong Han 
Cc: Sumit Semwal 
Cc: Alexei Starovoitov 
Cc: Juergen Gross 
Cc: Jason Cooper 
Cc: "David S. Miller" 
Cc: Oleg Nesterov 
Cc: Andrea Gelmini 
Cc: David Woodhouse 
Cc: Marc Zyngier 
Cc: Rabin Vincent 
Cc: "Maciej W. Rozycki" 
Cc: David Daney 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

MIPS: Fix buffer overflow in syscall_get_arguments()

2016-02-01T22:27:08+00:00

Since commit 4c21b8fd8f14 ("MIPS: seccomp: Handle indirect system calls
(o32)"), syscall_get_arguments() attempts to handle o32 indirect syscall
arguments by incrementing both the start argument number and the number
of arguments to fetch. However only the start argument number needs to
be incremented. The number of arguments does not change, they're just
shifted up by one, and in fact the output array is provided by the
caller and is likely only n entries long, so reading more arguments
overflows the output buffer.

In the case of seccomp, this results in it fetching 7 arguments starting
at the 2nd one, which overflows the unsigned long args[6] in
populate_seccomp_data(). This clobbers the $s0 register from
syscall_trace_enter() which __seccomp_phase1_filter() saved onto the
stack, into which syscall_trace_enter() had placed its syscall number
argument. This caused Chromium to crash.

Credit goes to Milko for tracking it down as far as $s0 being clobbered.

Fixes: 4c21b8fd8f14 ("MIPS: seccomp: Handle indirect system calls (o32)")
Reported-by: Milko Leporis 
Signed-off-by: James Hogan 
Cc: linux-mips@linux-mips.org
Cc:  # 3.15-
Patchwork: https://patchwork.linux-mips.org/patch/12213/
Signed-off-by: Ralf Baechle

MIPS: Fix syscall_get_nr for the syscall exit tracing.

2015-02-04T15:40:09+00:00

Register 2 is alredy overwritten by the return value when
syscall_trace_leave() is called.

Signed-off-by: Lars Persson 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9187/
Signed-off-by: Ralf Baechle

Merge git://git.infradead.org/users/eparis/audit

2014-10-19T23:25:56+00:00

Pull audit updates from Eric Paris:
 "So this change across a whole bunch of arches really solves one basic
  problem.  We want to audit when seccomp is killing a process.  seccomp
  hooks in before the audit syscall entry code.  audit_syscall_entry
  took as an argument the arch of the given syscall.  Since the arch is
  part of what makes a syscall number meaningful it's an important part
  of the record, but it isn't available when seccomp shoots the
  syscall...

  For most arch's we have a better way to get the arch (syscall_get_arch)
  So the solution was two fold: Implement syscall_get_arch() everywhere
  there is audit which didn't have it.  Use syscall_get_arch() in the
  seccomp audit code.  Having syscall_get_arch() everywhere meant it was
  a useless flag on the stack and we could get rid of it for the typical
  syscall entry.

  The other changes inside the audit system aren't grand, fixed some
  records that had invalid spaces.  Better locking around the task comm
  field.  Removing some dead functions and structs.  Make some things
  static.  Really minor stuff"

* git://git.infradead.org/users/eparis/audit: (31 commits)
  audit: rename audit_log_remove_rule to disambiguate for trees
  audit: cull redundancy in audit_rule_change
  audit: WARN if audit_rule_change called illegally
  audit: put rule existence check in canonical order
  next: openrisc: Fix build
  audit: get comm using lock to avoid race in string printing
  audit: remove open_arg() function that is never used
  audit: correct AUDIT_GET_FEATURE return message type
  audit: set nlmsg_len for multicast messages.
  audit: use union for audit_field values since they are mutually exclusive
  audit: invalid op= values for rules
  audit: use atomic_t to simplify audit_serial()
  kernel/audit.c: use ARRAY_SIZE instead of sizeof/sizeof[0]
  audit: reduce scope of audit_log_fcaps
  audit: reduce scope of audit_net_id
  audit: arm64: Remove the audit arch argument to audit_syscall_entry
  arm64: audit: Add audit hook in syscall_trace_enter/exit()
  audit: x86: drop arch from __audit_syscall_entry() interface
  sparc: implement is_32bit_task
  sparc: properly conditionalize use of TIF_32BIT
  ...

ARCH: AUDIT: implement syscall_get_arch for all arches

2014-09-23T20:20:10+00:00

For all arches which support audit implement syscall_get_arch()
They are all pretty easy and straight forward, stolen from how the call
to audit_syscall_entry() determines the arch.

Based-on-patch-by: Richard Briggs 
Signed-off-by: Eric Paris 
Cc: linux-ia64@vger.kernel.org
Cc: microblaze-uclinux@itee.uq.edu.au
Cc: linux-mips@linux-mips.org
Cc: linux@lists.openrisc.net
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: sparclinux@vger.kernel.org

MIPS: syscall: Fix AUDIT value for O32 processes on MIPS64

2014-08-19T16:24:39+00:00

On MIPS64, O32 processes set both TIF_32BIT_ADDR and
TIF_32BIT_REGS so the previous condition treated O32 applications
as N32 when evaluating seccomp filters. Fix the condition to check
both TIF_32BIT_{REGS, ADDR} for the N32 AUDIT flag.

Signed-off-by: Markos Chandras 
Patchwork: http://patchwork.linux-mips.org/patch/7480/
Cc:  # v3.15+
Signed-off-by: James Hogan