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
the only non-obvious part is that current_pt_regs() is really needed
here - task_pt_regs() is NULL for kernel threads; it's OK for ptrace
uses (the thing task_pt_regs() is intended for), but not for us.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
We can't emulate stwu since that may corrupt current exception stack.
So we will have to do real store operation in the exception return code.
Firstly we'll allocate a trampoline exception frame below the kprobed
function stack and copy the current exception frame to the trampoline.
Then we can do this real store operation to implement 'stwu', and reroute
the trampoline frame to r1 to complete this exception migration.
Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Commit 9778b696a0 incorrectly
changes the code setting the stack limit on entry to the
kernel to mark the thread_info at the bottom of the stack
out of bounds anymore. This fixes it.
Signed-off-by: Stuart Yoder <stuart.yoder@freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
When I "fixed" the CONFIG_TRACE_IRQFLAGS case on interrupt entry,
I screwed up a little bit with the test for user space vs. kernel.
The code is fine, there's just some dead code around it. I basically
removed the test and always create the added stack frame whether
coming from user or kernel since in any case we do need to save
a bunch of volatile registers or bad things would happen (we can
take page faults in the kernel for example).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
commit a546498f3b
introduced a regression on 32-bit when irq tracing
is enabled by exposing an old bug in our irq tracing
code for exception entry.
The code would save and restore some GPRs around the
calls to the C lockdep code, however, it tries to be
too smart for its own good and restores some of the
GPRs from the exception frame (as saved there on
exception entry).
However, for page faults, we do replace those GPRs with
arguments to do_page_fault before we call transfer_to_handler
and so restoring from the exception frame is plain wrong in
this case.
This was fine as long as we didn't touch the interrupt state
when taking page fault, but when I started doing it, it would
trigger the lockdep calls and the bug.
This fixes it by cleaning up that code a bit. It did create
a small stack frame for the sake of backtraces, so let's
make it a bit bigger and use it to save and restore the
stuff we care about.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We have a few problems when returning to userspace. This is a
quick set of fixes for 3.3, I'll look into a more comprehensive
rework for 3.4. This fixes:
- We kept interrupts soft-disabled when schedule'ing or calling
do_signal when returning to userspace as a result of a hardware
interrupt.
- Rename do_signal to do_notify_resume like all other archs (and
do_signal_pending back to do_signal, which it was before Roland
changed it).
- Add the missing call to key_replace_session_keyring() to
do_notify_resume().
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
32-bit variant of the previous patch for 64-bit:
<<
When an interrupt occurs in userspace, we can call trace_hardirqs_on/off()
With one level stack. But if we have irqsoff tracing enabled,
it checks both CALLER_ADDR0 and CALLER_ADDR1. The second call
goes two stack frames up. If this is from user space, then there may
not exist a second stack....
>>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Since STACK_FRAME_OVERHEAD is defined in asm/ptrace.h and that
is ASSEMBER safe, we can just include that instead of going via
asm-offsets.h.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This patch adds the base support for the 476 processor. The code was
primarily written by Ben Herrenschmidt and Torez Smith, but I've been
maintaining it for a while.
The goal is to have a single binary that will run on 44x and 47x, but
we still have some details to work out. The biggest is that the L1 cache
line size differs on the two platforms, but it's currently a compile-time
option.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Torez Smith <lnxtorez@linux.vnet.ibm.com>
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
The kernel uses SPRG registers for various purposes, typically in
low level assembly code as scratch registers or to hold per-cpu
global infos such as the PACA or the current thread_info pointer.
We want to be able to easily shuffle the usage of those registers
as some implementations have specific constraints realted to some
of them, for example, some have userspace readable aliases, etc..
and the current choice isn't always the best.
This patch should not change any code generation, and replaces the
usage of SPRN_SPRGn everywhere in the kernel with a named replacement
and adds documentation next to the definition of the names as to
what those are used for on each processor family.
The only parts that still use the original numbers are bits of KVM
or suspend/resume code that just blindly needs to save/restore all
the SPRGs.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Based on initial work from: Dale Farnsworth <dale@farnsworth.org>
Add the low level irq tracing hooks for 32-bit powerpc needed
to enable full lockdep functionality.
The approach taken to deal with the code in entry_32.S is that
we don't trace all the transitions of MSR:EE when we just turn
it off to peek at TI_FLAGS without races. Only when we are
calling into C code or returning from exceptions with a state
that have changed from what lockdep thinks.
There's a little bugger though: If we take an exception that
keeps interrupts enabled (such as an alignment exception) while
interrupts are enabled, we will call trace_hardirqs_on() on the
way back spurriously. Not a big deal, but to get rid of it would
require remembering in pt_regs that the exception was one of the
type that kept interrupts enabled which we don't know at this
stage. (Well, we could test all cases for regs->trap but that
sucks too much).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Kumar Gala <galak@kernel.crashing.org>
Create a new header that becomes a single location for defining PowerPC
opcodes used by code that is either generationg instructions
at runtime (fixups, debug, etc.), emulating instructions, or just
compiling instructions old assemblers don't know about.
We currently don't handle the floating point emulation or alignment decode
as both are better handled by the specific decode support they already
have.
Added support for the new dcbzl, dcbal, msgsnd, tlbilx, & wait instructions
since older assemblers don't know about them.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This patch ports the function graph tracer for PowerPC, but only
for static function tracing.
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Impact: clean up
Use a macro to save and restore the registers for PowerPC32,
since that code is duplicated.
This is similar to the work done by Cyrill Gorcunov for the
mcount code in x86_64.
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The Power ISA 2.06 spec introduces a standard MMU programming model that
is based on the Freescale Book-E MMU programing model. The Freescale
version is pretty backwards compatiable with the ISA 2.06 definition so
we are starting to refactor some of the Freescale code so it can be
easily shared.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Impact: quicken mcount calls that are not replaced by dyn ftrace
Dynamic ftrace no longer does on the fly recording of mcount locations.
The mcount locations are now found at compile time. The mcount
function no longer needs to store registers and call a stub function.
It can now just simply return.
Since there are some functions that do not get converted to a nop
(.init sections and other code that may disappear), this patch should
help speed up that code.
Also, the stub for mcount on PowerPC 32 can not be a simple branch
link register like it is on PowerPC 64. According to the ABI specification:
"The _mcount routine is required to restore the link register from
the stack so that the profiling code can be inserted transparently,
whether or not the profiled function saves the link register itself."
This means that we must restore the link register that was used
to make the call to mcount. The minimal mcount function for PPC32
ends up being:
mcount:
mflr r0
mtctr r0
lwz r0, 4(r1)
mtlr r0
bctr
Where we move the link register used to call mcount into the
ctr register, and then restore the link register from the stack.
Then we use the ctr register to jump back to the mcount caller.
The r0 register is free for us to use.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Due to confusion between the ftrace infrastructure and the gcc profiling
tracer "ftrace", this patch renames the config options from FTRACE to
FUNCTION_TRACER. The other two names that are offspring from FTRACE
DYNAMIC_FTRACE and FTRACE_MCOUNT_RECORD will stay the same.
This patch was generated mostly by script, and partially by hand.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This adds TIF_NOTIFY_RESUME support for powerpc. When set,
we call tracehook_notify_resume() on the way to user mode.
This overloads do_signal() to do the work, but changes its
arguments to it has the TIF_* bits handy in a register and
drops the useless first argument that was always zero.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Li Zhong
Al Viro
Linus Torvalds
Tiejun Chen
Stuart Yoder
Benjamin Herrenschmidt
Kevin Hao
Steven Rostedt
Stephen Rothwell
Dave Kleikamp
Kumar Gala
Steven Rostedt
Roland McGrath