This function can leak kernel stack data when the user siginfo_t has a
positive si_code value. The top 16 bits of si_code descibe which fields
in the siginfo_t union are active, but they are treated inconsistently
between copy_siginfo_from_user32, copy_siginfo_to_user32 and
copy_siginfo_to_user.
copy_siginfo_from_user32 is called from rt_sigqueueinfo and
rt_tgsigqueueinfo in which the user has full control overthe top 16 bits
of si_code.
This fixes the following information leaks:
x86: 8 bytes leaked when sending a signal from a 32-bit process to
itself. This leak grows to 16 bytes if the process uses x32.
(si_code = __SI_CHLD)
x86: 100 bytes leaked when sending a signal from a 32-bit process to
a 64-bit process. (si_code = -1)
sparc: 4 bytes leaked when sending a signal from a 32-bit process to a
64-bit process. (si_code = any)
parsic and s390 have similar bugs, but they are not vulnerable because
rt_[tg]sigqueueinfo have checks that prevent sending a positive si_code
to a different process. These bugs are also fixed for consistency.
Signed-off-by: Amanieu d'Antras <amanieu@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull arch/tile updates from Chris Metcalf:
"These are mostly nohz_full changes, plus a smattering of minor fixes
(notably a couple for ftrace)"
* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
tile: nohz: warn if nohz_full uses hypervisor shared cores
tile: ftrace: fix function_graph tracer issues
tile: map data region shadow of kernel as R/W
tile: support CONTEXT_TRACKING and thus NOHZ_FULL
tile: support arch_irq_work_raise
arch: tile: fix null pointer dereference on pt_regs pointer
tile/elf: reorganize notify_exec()
tile: use si_int instead of si_ptr for compat_siginfo
To be compatible with the generic get_compat_sigevent(), the
copy_siginfo_to_user32() and thus copy_siginfo_from_user32()
have to use si_int instead of si_ptr. Using si_ptr means that
for the case of ILP32 compat code running in big-endian mode,
we would end up copying the high 32 bits of the pointer value
into si_int instead of the desired low 32 bits.
Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
As execution domain support is gone we can remove
signal translation from the signal code and remove
exec_domain from thread_info.
Signed-off-by: Richard Weinberger <richard@nod.at>
Use the more generic functions get_signal() signal_setup_done()
for signal delivery.
Signed-off-by: Richard Weinberger <richard@nod.at>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
This change creates the framework for vDSO calls, makes the existing
rt_sigreturn() mechanism use it, and adds a fast gettimeofday().
Now that we need to expose the vDSO address to userspace, we add
AT_SYSINFO_EHDR to the set of aux entries provided to userspace.
(You can disable any extra vDSO support by booting with vdso=0,
but the rt_sigreturn vDSO page will still be provided.)
Note that glibc has supported the tile vDSO since release 2.17.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Using the new current_pt_regs() model, we can remove some trampolines
from assembly code and call directly to the C syscall implementations.
rt_sigreturn() and clone() still need some assembly wrapping, but no
longer are passed a pt_regs pointer. sigaltstack() and the
tilepro-specific cmpxchg_badaddr() syscalls are now just straight C.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Pull pile 2 of execve and kernel_thread unification work from Al Viro:
"Stuff in there: kernel_thread/kernel_execve/sys_execve conversions for
several more architectures plus assorted signal fixes and cleanups.
There'll be more (in particular, real fixes for the alpha
do_notify_resume() irq mess)..."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (43 commits)
alpha: don't open-code trace_report_syscall_{enter,exit}
Uninclude linux/freezer.h
m32r: trim masks
avr32: trim masks
tile: don't bother with SIGTRAP in setup_frame
microblaze: don't bother with SIGTRAP in setup_rt_frame()
mn10300: don't bother with SIGTRAP in setup_frame()
frv: no need to raise SIGTRAP in setup_frame()
x86: get rid of duplicate code in case of CONFIG_VM86
unicore32: remove pointless test
h8300: trim _TIF_WORK_MASK
parisc: decide whether to go to slow path (tracesys) based on thread flags
parisc: don't bother looping in do_signal()
parisc: fix double restarts
bury the rest of TIF_IRET
sanitize tsk_is_polling()
bury _TIF_RESTORE_SIGMASK
unicore32: unobfuscate _TIF_WORK_MASK
mips: NOTIFY_RESUME is not needed in TIF masks
mips: merge the identical "return from syscall" per-ABI code
...
Conflicts:
arch/arm/include/asm/thread_info.h
This is a preparatory patch for the introduction of NT_SIGINFO elf note.
Make the location of compat_siginfo_t uniform across eight architectures
which have it. Now it can be pulled in by including asm/compat.h or
linux/compat.h.
Most of the copies are verbatim. compat_uid[32]_t had to be replaced by
__compat_uid[32]_t. compat_uptr_t had to be moved up before
compat_siginfo_t in asm/compat.h on a several architectures (tile already
had it moved up). compat_sigval_t had to be relocated from linux/compat.h
to asm/compat.h.
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Amerigo Wang <amwang@redhat.com>
Cc: "Jonathan M. Foote" <jmfoote@cert.org>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Only 3 out of 63 do not. Renamed the current variant to __set_current_blocked(),
added set_current_blocked() that will exclude unblockable signals, switched
open-coded instances to it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This passes siginfo and mcontext to tilegx32 signal handlers that
don't have SA_SIGINFO set just as we have been doing for tilegx64.
Cc: stable@vger.kernel.org
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
As described in e6fa16ab ("signal: sigprocmask() should do
retarget_shared_pending()") the modification of current->blocked is
incorrect as we need to check whether the signal we're about to block
is pending in the shared queue.
Also, use the new helper function introduced in commit 5e6292c0f2
("signal: add block_sigmask() for adding sigmask to current->blocked")
which centralises the code for updating current->blocked after
successfully delivering a signal and reduces the amount of duplicate
code across architectures. In the past some architectures got this
code wrong, so using this helper function should stop that from
happening again.
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
This change adds support for /proc/sys/debug/exception-trace to tile.
Like x86 and sparc, by default it is set to "1", generating a one-line
printk whenever a user process crashes. By setting it to "2", we get
a much more complete userspace diagnostic at crash time, including
a user-space backtrace, register dump, and memory dump around the
address of the crash.
Some vestiges of the Tilera-internal version of this support are
removed with this patch (the show_crashinfo variable and the
arch_coredump_signal function). We retain a "crashinfo" boot parameter
which allows you to set the boot-time value of exception-trace.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
The current tile rt_sigreturn() syscall pattern uses the common idiom
of loading up pt_regs with all the saved registers from the time of
the signal, then anticipating the fact that we will clobber the ABI
"return value" register (r0) as we return from the syscall by setting
the rt_sigreturn return value to whatever random value was in the pt_regs
for r0.
However, this breaks in our 64-bit kernel when running "compat" tasks,
since we always sign-extend the "return value" register to properly
handle returned pointers that are in the upper 2GB of the 32-bit compat
address space. Doing this to the sigreturn path then causes occasional
random corruption of the 64-bit r0 register.
Instead, we stop doing the crazy "load the return-value register"
hack in sigreturn. We already have some sigreturn-specific assembly
code that we use to pass the pt_regs pointer to C code. We extend that
code to also set the link register to point to a spot a few instructions
after the usual syscall return address so we don't clobber the saved r0.
Now it no longer matters what the rt_sigreturn syscall returns, and the
pt_regs structure can be cleanly and completely reloaded.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
The big kernel lock has been removed from all these files at some point,
leaving only the #include.
Remove this too as a cleanup.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With this change we now include <asm-generic/syscalls.h> into the "tile"
version of the header. To take full advantage of the prototypes there,
we also change our naming convention for "struct pt_regs *" syscalls so
that, e.g., _sys_execve() is the "true" syscall entry, which sets the
appropriate register to point to the pt_regs before calling sys_execve().
While doing this I realized I no longer needed the fork and vfork
entry point stubs, since those functions aren't in the generic
syscall ABI, so I removed them as well.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
First, the siginfo preamble wasn't quite right; we need to indicate
that we are padding up to 4 ints of preamble for 64-bit code, and
then for compat mode we need to pad differently, using only 3 ints.
Second, the C ABI requires a save area of two registers, not two
pointers, since in compat mode we have 64-bit registers all of which
we need to save, even though we only have 32-bit VAs.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
This commit is primarily changes caused by reviewing "sparse"
and "checkpatch" output on our sources, so is somewhat noisy, since
things like "printk() -> pr_err()" (or whatever) throughout the
codebase tend to get tedious to read. Rather than trying to tease
apart precisely which things changed due to which type of code
review, this commit includes various cleanups in the code:
- sparse: Add declarations in headers for globals.
- sparse: Fix __user annotations.
- sparse: Using gfp_t consistently instead of int.
- sparse: removing functions not actually used.
- checkpatch: Clean up printk() warnings by using pr_info(), etc.;
also avoid partial-line printks except in bootup code.
- checkpatch: Use exposed structs rather than typedefs.
- checkpatch: Change some C99 comments to C89 comments.
In addition, a couple of minor other changes are rolled in
to this commit:
- Add support for a "raise" instruction to cause SIGFPE, etc., to be raised.
- Remove some compat code that is unnecessary when we fully eliminate
some of the deprecated syscalls from the generic syscall ABI.
- Update the tile_defconfig to reflect current config contents.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
This change is the core kernel support for TILEPro and TILE64 chips.
No driver support (except the console driver) is included yet.
This includes the relevant Linux headers in asm/; the low-level
low-level "Tile architecture" headers in arch/, which are
shared with the hypervisor, etc., and are build-system agnostic;
and the relevant hypervisor headers in hv/.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Reviewed-by: Paul Mundt <lethal@linux-sh.org>
