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>
... and get rid of in-kernel syscalls in kernel_thread() 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 9778b696a0188ad3b3524b383953ee73b31b7b68 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>
Signed-off-by: Stuart Yoder <stuart.yoder@freescale.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
commit a546498f3bf9aac311c66f965186373aee2ca0b0 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> ---
The trace_hardirqs_off will use CALLER_ADDR0 and CALLER_ADDR1. If an exception occurs in user mode, there is only one stack frame on the stack and accessing the CALLER_ADDR1 will causes the following call trace. So we create a dummy stack frame to make trace_hardirqs_off happy. WARNING: at kernel/smp.c:459 Modules linked in: NIP: c0093280 LR: c00930a0 CTR: c0010780 REGS: edb87ae0 TRAP: 0700 Not tainted (3.1.0) MSR: 00021002 <ME,CE> CR: 28002888 XER: 00000000 TASK = edce2ac0[17658] 'mthread-lock-on' THREAD: edb86000 CPU: 5 GPR00: 00000001 edb87b90 edce2ac0 00000005 c0019594 edb87bd8 00000001 00000fe3 GPR08: 00041000 c084138c 4e20120d edb87b90 48002888 1001aa7c 00000000 00000000 GPR16: 48830000 10012a8c 00000000 10000af4 00000001 c0810000 00000000 00000000 GPR24: ee9aa920 c0816a18 00000000 00000005 c0019594 edb87bd8 ee20178c edb87b90 NIP [c0093280] smp_call_function_many+0x214/0x2b4 LR [c00930a0] smp_call_function_many+0x34/0x2b4 Call Trace: [edb87b90] [c00930a0] smp_call_function_many+0x34/0x2b4 (unreliable) [edb87bd0] [c00194ec] __flush_tlb_page+0xac/0x100 [edb87c00] [c001957c] flush_tlb_page+0x3c/0x54 [edb87c10] [c00180ac] ptep_set_access_flags+0x74/0x12c [edb87c40] [c0128068] handle_pte_fault+0x2f0/0x9ac [edb87cb0] [c0128c3c] handle_mm_fault+0x104/0x1dc [edb87ce0] [c05f40f4] do_page_fault+0x2dc/0x630 [edb87e50] [c001078c] handle_page_fault+0xc/0x80 Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>