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  1. 09 Nov, 2017 4 commits
    • James Hogan's avatar
      MIPS/ptrace: Pick up ptrace/seccomp changed syscalls · b6318a90
      James Hogan authored 
      The MIPS syscall_trace_enter() allows the system call number to be
altered or cancelled by a ptrace tracer, via the normal ptrace hook
(PTRACE_SYSCALL) and changing the system call number register on entry,
and similarly via seccomp (PTRACE_EVENT_SECCOMP when a seccomp filter
returns SECCOMP_RET_TRACE).

Be sure to update the syscall local variable if this happens, so that
seccomp will filter the correct system call number if the normal ptrace
hook changes it first, and so that if either the normal ptrace hook or
seccomp change it the correct system call number is passed to the trace
event.

This won't have any effect until the next commit, which fixes ptrace to
update thread_info::syscall.

Fixes: c2d9f177 ("MIPS: Fix syscall_get_nr for the syscall exit tracing.")
Signed-off-by: default avatarJames Hogan <jhogan@kernel.org>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Lars Persson <lars.persson@axis.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Will Drewry <wad@chromium.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16996/
      b6318a90
    • Maciej W. Rozycki's avatar
      MIPS: Fix an n32 core file generation regset support regression · 547da673
      Maciej W. Rozycki authored 
      Fix a commit 7aeb753b ("MIPS: Implement task_user_regset_view.")
regression, then activated by commit 6a9c001b ("MIPS: Switch ELF
core dumper to use regsets.)", that caused n32 processes to dump o32
core files by failing to set the EF_MIPS_ABI2 flag in the ELF core file
header's `e_flags' member:

$ file tls-core
tls-core: ELF 32-bit MSB executable, MIPS, N32 MIPS64 rel2 version 1 (SYSV), [...]
$ ./tls-core
Aborted (core dumped)
$ file core
core: ELF 32-bit MSB core file MIPS, MIPS-I version 1 (SYSV), SVR4-style
$

Previously the flag was set as the result of a:

statement placed in arch/mips/kernel/binfmt_elfn32.c, however in the
regset case, i.e. when CORE_DUMP_USE_REGSET is set, ELF_CORE_EFLAGS is
no longer used by `fill_note_info' in fs/binfmt_elf.c, and instead the
`->e_flags' member of the regset view chosen is.  We have the views
defined in arch/mips/kernel/ptrace.c, however only an o32 and an n64
one, and the latter is used for n32 as well.  Consequently an o32 core
file is incorrectly dumped from n32 processes (the ELF32 vs ELF64 class
is chosen elsewhere, and the 32-bit one is correctly selected for n32).

Correct the issue then by defining an n32 regset view and using it as
appropriate.  Issue discovered in GDB testing.

Fixes: 7aeb753b ("MIPS: Implement task_user_regset_view.")
Signed-off-by: default avatarMaciej W. Rozycki <macro@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Djordje Todorovic <djordje.todorovic@rt-rk.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 3.13+
Patchwork: https://patchwork.linux-mips.org/patch/17617/Signed-off-by: default avatarJames Hogan <jhogan@kernel.org>
      547da673
    • James Hogan's avatar
      MIPS: Fix MIPS64 FP save/restore on 32-bit kernels · 22b8ba76
      James Hogan authored 
      32-bit kernels can be configured to support MIPS64, in which case
neither CONFIG_64BIT or CONFIG_CPU_MIPS32_R* will be set. This causes
the CP0_Status.FR checks at the point of floating point register save
and restore to be compiled out, which results in odd FP registers not
being saved or restored to the task or signal context even when
CP0_Status.FR is set.

Fix the ifdefs to use CONFIG_CPU_MIPSR2 and CONFIG_CPU_MIPSR6, which are
enabled for the relevant revisions of either MIPS32 or MIPS64, along
with some other CPUs such as Octeon (r2), Loongson1 (r2), XLP (r2),
Loongson 3A R2.

The suspect code originates from commit 597ce172 ("MIPS: Support for
64-bit FP with O32 binaries") in v3.14, however the code in
__enable_fpu() was consistent and refused to set FR=1, falling back to
software FPU emulation. This was suboptimal but should be functionally
correct.

Commit fcc53b5f ("MIPS: fpu.h: Allow 64-bit FPU on a 64-bit MIPS R6
CPU") in v4.2 (and stable tagged back to 4.0) later introduced the bug
by updating __enable_fpu() to set FR=1 but failing to update the other
similar ifdefs to enable FR=1 state handling.

Fixes: fcc53b5f ("MIPS: fpu.h: Allow 64-bit FPU on a 64-bit MIPS R6 CPU")
Signed-off-by: default avatarJames Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 4.0+
Patchwork: https://patchwork.linux-mips.org/patch/16739/
      22b8ba76
    • Florian Fainelli's avatar
      MIPS: page.h: Define virt_to_pfn() · 37d15948
      Florian Fainelli authored 
      Define virt_to_pfn() based on the existing definition of virt_to_page()
which already does a PFN_DOWN(vir_to_phys(kaddr)).
Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15409/Signed-off-by: default avatarJames Hogan <jhogan@kernel.org>
      37d15948
  3. 08 Nov, 2017 8 commits
  5. 07 Nov, 2017 16 commits
  7. 09 Oct, 2017 8 commits
  9. 07 Oct, 2017 4 commits
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