linux.git/arch/mips/kernel/ptrace.c, branch v5.16

mips: switch to ->regset_get()

2020-07-27T18:31:08+00:00

Signed-off-by: Al Viro

mm: don't include asm/pgtable.h if linux/mm.h is already included

2020-06-09T16:39:13+00:00

Patch series "mm: consolidate definitions of page table accessors", v2.

The low level page table accessors (pXY_index(), pXY_offset()) are
duplicated across all architectures and sometimes more than once.  For
instance, we have 31 definition of pgd_offset() for 25 supported
architectures.

Most of these definitions are actually identical and typically it boils
down to, e.g.

static inline unsigned long pmd_index(unsigned long address)
{
        return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
}

static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
{
        return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address);
}

These definitions can be shared among 90% of the arches provided
XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined.

For architectures that really need a custom version there is always
possibility to override the generic version with the usual ifdefs magic.

These patches introduce include/linux/pgtable.h that replaces
include/asm-generic/pgtable.h and add the definitions of the page table
accessors to the new header.

This patch (of 12):

The linux/mm.h header includes  to allow inlining of the
functions involving page table manipulations, e.g.  pte_alloc() and
pmd_alloc().  So, there is no point to explicitly include 
in the files that include .

The include statements in such cases are remove with a simple loop:

	for f in $(git grep -l "include ") ; do
		sed -i -e '/include / d' $f
	done

Signed-off-by: Mike Rapoport 
Signed-off-by: Andrew Morton 
Cc: Arnd Bergmann 
Cc: Borislav Petkov 
Cc: Brian Cain 
Cc: Catalin Marinas 
Cc: Chris Zankel 
Cc: "David S. Miller" 
Cc: Geert Uytterhoeven 
Cc: Greentime Hu 
Cc: Greg Ungerer 
Cc: Guan Xuetao 
Cc: Guo Ren 
Cc: Heiko Carstens 
Cc: Helge Deller 
Cc: Ingo Molnar 
Cc: Ley Foon Tan 
Cc: Mark Salter 
Cc: Matthew Wilcox 
Cc: Matt Turner 
Cc: Max Filippov 
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Mike Rapoport 
Cc: Nick Hu 
Cc: Paul Walmsley 
Cc: Richard Weinberger 
Cc: Rich Felker 
Cc: Russell King 
Cc: Stafford Horne 
Cc: Thomas Bogendoerfer 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Cc: Vincent Chen 
Cc: Vineet Gupta 
Cc: Will Deacon 
Cc: Yoshinori Sato 
Link: http://lkml.kernel.org/r/20200514170327.31389-1-rppt@kernel.org
Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org
Signed-off-by: Linus Torvalds

Merge tag 'audit-pr-20190507' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit

2019-05-08T02:06:04+00:00

Pull audit updates from Paul Moore:
 "We've got a reasonably broad set of audit patches for the v5.2 merge
  window, the highlights are below:

   - The biggest change, and the source of all the arch/* changes, is
     the patchset from Dmitry to help enable some of the work he is
     doing around PTRACE_GET_SYSCALL_INFO.

     To be honest, including this in the audit tree is a bit of a
     stretch, but it does help move audit a little further along towards
     proper syscall auditing for all arches, and everyone else seemed to
     agree that audit was a "good" spot for this to land (or maybe they
     just didn't want to merge it? dunno.).

   - We can now audit time/NTP adjustments.

   - We continue the work to connect associated audit records into a
     single event"

* tag 'audit-pr-20190507' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit: (21 commits)
  audit: fix a memory leak bug
  ntp: Audit NTP parameters adjustment
  timekeeping: Audit clock adjustments
  audit: purge unnecessary list_empty calls
  audit: link integrity evm_write_xattrs record to syscall event
  syscall_get_arch: add "struct task_struct *" argument
  unicore32: define syscall_get_arch()
  Move EM_UNICORE to uapi/linux/elf-em.h
  nios2: define syscall_get_arch()
  nds32: define syscall_get_arch()
  Move EM_NDS32 to uapi/linux/elf-em.h
  m68k: define syscall_get_arch()
  hexagon: define syscall_get_arch()
  Move EM_HEXAGON to uapi/linux/elf-em.h
  h8300: define syscall_get_arch()
  c6x: define syscall_get_arch()
  arc: define syscall_get_arch()
  Move EM_ARCOMPACT and EM_ARCV2 to uapi/linux/elf-em.h
  audit: Make audit_log_cap and audit_copy_inode static
  audit: connect LOGIN record to its syscall record
  ...

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)

syscall_get_arch: add "struct task_struct *" argument

2019-03-21T01:12:36+00:00

This argument is required to extend the generic ptrace API with
PTRACE_GET_SYSCALL_INFO request: syscall_get_arch() is going
to be called from ptrace_request() along with syscall_get_nr(),
syscall_get_arguments(), syscall_get_error(), and
syscall_get_return_value() functions with a tracee as their argument.

The primary intent is that the triple (audit_arch, syscall_nr, arg1..arg6)
should describe what system call is being called and what its arguments
are.

Reverts: 5e937a9ae913 ("syscall_get_arch: remove useless function arguments")
Reverts: 1002d94d3076 ("syscall.h: fix doc text for syscall_get_arch()")
Reviewed-by: Andy Lutomirski  # for x86
Reviewed-by: Palmer Dabbelt 
Acked-by: Paul Moore 
Acked-by: Paul Burton  # MIPS parts
Acked-by: Michael Ellerman  (powerpc)
Acked-by: Kees Cook  # seccomp parts
Acked-by: Mark Salter  # for the c6x bit
Cc: Elvira Khabirova 
Cc: Eugene Syromyatnikov 
Cc: Oleg Nesterov 
Cc: x86@kernel.org
Cc: linux-alpha@vger.kernel.org
Cc: linux-snps-arc@lists.infradead.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-m68k@lists.linux-m68k.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
Cc: linux-audit@redhat.com
Signed-off-by: Dmitry V. Levin 
Signed-off-by: Paul Moore

Remove 'type' argument from access_ok() function

2019-01-04T02:57:57+00:00

Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.

It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access.  But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.

A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model.  And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.

This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.

There were a couple of notable cases:

 - csky still had the old "verify_area()" name as an alias.

 - the iter_iov code had magical hardcoded knowledge of the actual
   values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
   really used it)

 - microblaze used the type argument for a debug printout

but other than those oddities this should be a total no-op patch.

I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something.  Any missed conversion should be trivially fixable, though.

Signed-off-by: Linus Torvalds

MIPS: ptrace: introduce NT_MIPS_MSA regset

2018-11-21T05:05:39+00:00

The current methods for obtaining FP context via ptrace only provide
either 32 or 64 bits per data register. With MSA, where vector registers
are aliased with scalar FP data registers, those registers are 128 bits
wide. Thus a new mechanism is required for userland to access those
registers via ptrace. This patch introduces an NT_MIPS_MSA regset which
provides, in this order:

  - The full 128 bits value of each vector register, in native
    endianness saved as though elements are doubles. That is, the format
    of each vector register is as would be obtained by saving it to
    memory using an st.d instruction.

  - The 32 bit scalar FP implementation register (FIR).

  - The 32 bit scalar FP control & status register (FCSR).

  - The 32 bit MSA implementation register (MSAIR).

  - The 32 bit MSA control & status register (MSACSR).

The provision of the FIR & FCSR registers in addition to the MSA
equivalents allows scalar FP context to be retrieved as a subset of
the context available via this regset. Along with the MSA equivalents
they also nicely form the final 128 bit "register" of the regset.

Signed-off-by: Paul Burton 
Patchwork: https://patchwork.linux-mips.org/patch/21180/
Cc: linux-mips@linux-mips.org

MIPS: ptrace: Remove FP support when CONFIG_MIPS_FP_SUPPORT=n

2018-11-09T18:23:17+00:00

When CONFIG_MIPS_FP_SUPPORT=n we don't support floating point, so remove
the related ptrace support. Besides removing code which should not be
needed, this prepares us for the removal of FPU state in struct
task_struct which this code requires.

Signed-off-by: Paul Burton 
Patchwork: https://patchwork.linux-mips.org/patch/21008/
Cc: linux-mips@linux-mips.org

MIPS: Simplify FP context initialization

2018-11-09T18:23:13+00:00

MIPS has up until now had 3 different ways for a task's floating point
context to be initialized:

  - If the task's first use of FP involves it gaining ownership of an
    FPU then _init_fpu() is used to initialize the FPU's registers such
    that they all contain ~0, and the FPU registers will be stored to
    struct thread_info later (eg. when context switching).

  - If the task first uses FP on a CPU without an associated FPU then
    fpu_emulator_init_fpu() initializes the task's floating point
    register state in struct thread_info such that all floating point
    register contain the bit pattern 0x7ff800007ff80000, different to
    the _init_fpu() behaviour.

  - If a task's floating point context is first accessed via ptrace then
    init_fp_ctx() initializes the floating point register state in
    struct thread_info to ~0, giving equivalent state to _init_fpu().

The _init_fpu() path has 2 separate implementations - one for r2k/r3k
style systems & one for r4k style systems. The _init_fpu() path also
requires that we be careful to clear & restore the value of the
Config5.FRE bit on modern systems in order to avoid inadvertently
triggering floating point exceptions.

None of this code is in a performance critical hot path - it runs only
the first time a task uses floating point. As such it doesn't seem to
warrant the complications of maintaining the _init_fpu() path.

Remove _init_fpu() & fpu_emulator_init_fpu(), instead using
init_fp_ctx() consistently to initialize floating point register state
in struct thread_info. Upon a task's first use of floating point this
will typically mean that we initialize state in memory & then load it
into FPU registers using _restore_fp() just as we would on a context
switch. For other paths such as __compute_return_epc_for_insn() or
mipsr2_decoder() this results in a significant simplification of the
work to be done.

Signed-off-by: Paul Burton 
Patchwork: https://patchwork.linux-mips.org/patch/21002/
Cc: linux-mips@linux-mips.org

MIPS: Add FP_MODE regset support

2018-07-19T20:58:44+00:00

Define an NT_MIPS_FP_MODE core file note and implement a corresponding
regset holding the state handled by PR_SET_FP_MODE and PR_GET_FP_MODE
prctl(2) requests.  This lets debug software correctly interpret the
contents of floating-point general registers both in live debugging and
in core files, and also switch floating-point modes of a live process.

[paul.burton@mips.com:
  - Changed NT_MIPS_FP_MODE to 0x801 to match first nibble of
    NT_MIPS_DSP, which was also changed to avoid a conflict.]

Signed-off-by: Maciej W. Rozycki 
Signed-off-by: Paul Burton 
Patchwork: https://patchwork.linux-mips.org/patch/19331/
Cc: James Hogan 
Cc: Ralf Baechle 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org