linux-stable.git/arch/powerpc/kernel/entry_32.S, branch linux-4.9.y

powerpc/fsl: Sanitize the syscall table for NXP PowerPC 32 bit platforms

2019-04-17T06:36:41+00:00

commit c28218d4abbf4f2035495334d8bfcba64bda4787 upstream.

Used barrier_nospec to sanitize the syscall table.

Signed-off-by: Diana Craciun 
Signed-off-by: Michael Ellerman 
Signed-off-by: Sasha Levin

powerpc/32: Clear on-stack exception marker upon exception return

2019-03-23T12:19:51+00:00

commit 9580b71b5a7863c24a9bd18bcd2ad759b86b1eff upstream.

Clear the on-stack STACK_FRAME_REGS_MARKER on exception exit in order
to avoid confusing stacktrace like the one below.

  Call Trace:
  [c0e9dca0] [c01c42a0] print_address_description+0x64/0x2bc (unreliable)
  [c0e9dcd0] [c01c4684] kasan_report+0xfc/0x180
  [c0e9dd10] [c0895130] memchr+0x24/0x74
  [c0e9dd30] [c00a9e38] msg_print_text+0x124/0x574
  [c0e9dde0] [c00ab710] console_unlock+0x114/0x4f8
  [c0e9de40] [c00adc60] vprintk_emit+0x188/0x1c4
  --- interrupt: c0e9df00 at 0x400f330
      LR = init_stack+0x1f00/0x2000
  [c0e9de80] [c00ae3c4] printk+0xa8/0xcc (unreliable)
  [c0e9df20] [c0c27e44] early_irq_init+0x38/0x108
  [c0e9df50] [c0c15434] start_kernel+0x310/0x488
  [c0e9dff0] [00003484] 0x3484

With this patch the trace becomes:

  Call Trace:
  [c0e9dca0] [c01c42c0] print_address_description+0x64/0x2bc (unreliable)
  [c0e9dcd0] [c01c46a4] kasan_report+0xfc/0x180
  [c0e9dd10] [c0895150] memchr+0x24/0x74
  [c0e9dd30] [c00a9e58] msg_print_text+0x124/0x574
  [c0e9dde0] [c00ab730] console_unlock+0x114/0x4f8
  [c0e9de40] [c00adc80] vprintk_emit+0x188/0x1c4
  [c0e9de80] [c00ae3e4] printk+0xa8/0xcc
  [c0e9df20] [c0c27e44] early_irq_init+0x38/0x108
  [c0e9df50] [c0c15434] start_kernel+0x310/0x488
  [c0e9dff0] [00003484] 0x3484

Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild

2016-10-14T21:26:58+00:00

Pull kbuild updates from Michal Marek:

 - EXPORT_SYMBOL for asm source by Al Viro.

   This does bring a regression, because genksyms no longer generates
   checksums for these symbols (CONFIG_MODVERSIONS). Nick Piggin is
   working on a patch to fix this.

   Plus, we are talking about functions like strcpy(), which rarely
   change prototypes.

 - Fixes for PPC fallout of the above by Stephen Rothwell and Nick
   Piggin

 - fixdep speedup by Alexey Dobriyan.

 - preparatory work by Nick Piggin to allow architectures to build with
   -ffunction-sections, -fdata-sections and --gc-sections

 - CONFIG_THIN_ARCHIVES support by Stephen Rothwell

 - fix for filenames with colons in the initramfs source by me.

* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: (22 commits)
  initramfs: Escape colons in depfile
  ppc: there is no clear_pages to export
  powerpc/64: whitelist unresolved modversions CRCs
  kbuild: -ffunction-sections fix for archs with conflicting sections
  kbuild: add arch specific post-link Makefile
  kbuild: allow archs to select link dead code/data elimination
  kbuild: allow architectures to use thin archives instead of ld -r
  kbuild: Regenerate genksyms lexer
  kbuild: genksyms fix for typeof handling
  fixdep: faster CONFIG_ search
  ia64: move exports to definitions
  sparc32: debride memcpy.S a bit
  [sparc] unify 32bit and 64bit string.h
  sparc: move exports to definitions
  ppc: move exports to definitions
  arm: move exports to definitions
  s390: move exports to definitions
  m68k: move exports to definitions
  alpha: move exports to actual definitions
  x86: move exports to actual definitions
  ...

powerpc/32: Remove CLR_TOP32

2016-09-22T21:54:22+00:00

CLR_TOP32() is defined as blank. Last useful instance of CLR_TOP32()
was removed by commit 40ef8cbc6d360 ("powerpc: Get 64-bit configs to
compile with ARCH=powerpc") in 2005.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman

ppc: move exports to definitions

2016-08-08T03:50:09+00:00

Signed-off-by: Al Viro

powerpc32: provide VIRT_CPU_ACCOUNTING

2016-07-09T06:43:50+00:00

This patch provides VIRT_CPU_ACCOUTING to PPC32 architecture.
PPC32 doesn't have the PACA structure, so we use the task_info
structure to store the accounting data.

In order to reuse on PPC32 the PPC64 functions, all u64 data has
been replaced by 'unsigned long' so that it is u32 on PPC32 and
u64 on PPC64

Signed-off-by: Christophe Leroy 
Signed-off-by: Scott Wood

powerpc/kernel: Change the do_syscall_trace_enter() API

2015-07-29T01:56:11+00:00

The API for calling do_syscall_trace_enter() is currently sensible
enough, it just returns the (modified) syscall number.

However once we enable seccomp filter it will get more complicated. When
seccomp filter runs, the seccomp kernel code (via SECCOMP_RET_ERRNO), or
a ptracer (via SECCOMP_RET_TRACE), may reject the syscall and *may* or may
*not* set a return value in r3.

That means the assembler that calls do_syscall_trace_enter() can not
blindly return ENOSYS, it needs to only return ENOSYS if a return value
has not already been set.

There is no way to implement that logic with the current API. So change
the do_syscall_trace_enter() API to make it deal with the return code
juggling, and the assembler can then just return whatever return code it
is given.

Signed-off-by: Michael Ellerman 
Reviewed-by: Kees Cook

powerpc/kernel: Switch to using MAX_ERRNO

2015-07-29T01:56:11+00:00

Currently on powerpc we have our own #define for the highest (negative)
errno value, called _LAST_ERRNO. This is defined to be 516, for reasons
which are not clear.

The generic code, and x86, use MAX_ERRNO, which is defined to be 4095.

In particular seccomp uses MAX_ERRNO to restrict the value that a
seccomp filter can return.

Currently with the mismatch between _LAST_ERRNO and MAX_ERRNO, a seccomp
tracer wanting to return 600, expecting it to be seen as an error, would
instead find on powerpc that userspace sees a successful syscall with a
return value of 600.

To avoid this inconsistency, switch powerpc to use MAX_ERRNO.

We are somewhat confident that generic syscalls that can return a
non-error value above negative MAX_ERRNO have already been updated to
use force_successful_syscall_return().

I have also checked all the powerpc specific syscalls, and believe that
none of them expect to return a non-error value between -MAX_ERRNO and
-516. So this change should be safe ...

Acked-by: Benjamin Herrenschmidt 
Signed-off-by: Michael Ellerman 
Reviewed-by: Kees Cook

powerpc: Remove old compile time disabled syscall tracing code

2015-02-02T03:51:32+00:00

We have code to do syscall tracing which is disabled at compile time by
default. It's not been touched since the dawn of time (ie. v2.6.12).

There are now better ways to do syscall tracing, ie. using the
raw_syscall, or syscall tracepoints.

For the specific case of tracing syscalls at boot on a system that
doesn't get to userspace, you can boot with:

  trace_event=syscalls tp_printk=on

Which will trace syscalls from boot, and echo all output to the console.

Signed-off-by: Michael Ellerman

powerpc: Rename _TIF_SYSCALL_T_OR_A to _TIF_SYSCALL_DOTRACE

2015-01-23T03:02:51+00:00

Once upon a time, at least 9 years ago (< 2.6.12), _TIF_SYSCALL_T_OR_A
meant "TRACE or AUDIT". But these days it means TRACE or AUDIT or
SECCOMP or TRACEPOINT or NOHZ.

All of those are implemented via syscall_dotrace() so rename the flag to
that to try and clarify things.

Signed-off-by: Michael Ellerman