We need to keep building sigframes until no pending signals remain.
Wrap do_notify_resume() calls into loops; do _not_ allow syscall
restart logics to trigger after the first iteration.
Incidentally, comments about pending signals that should (somehow)
be in r18 are pure BS. Doesn't work that way and cannot work that
way, sorry...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
solution a-la arm one - pick a callee-saved register (r30), set it
non-zero when entering a syscall, have sigreturn wrapper zero it out
and pass the value in it to do_notify_resume() as "in_syscall" (actually,
"restarts allowed") argument.
Note that we don't give a damn about ret_from_fork() - return value
is not restart-worthy anyway.
Possible remaining bug: on !MMU we still have _debug_exception()
restartable. If it hits with -ERESTART_... accidentally in r3, fun happens.
MMU does _not_ have _debug_exception() restartable. If that's decided to
be a bug (as I strongly suspect it to be), we'll just need to replace
setting r30 to 1 with setting r30 to 0 in !MMU _debug_exception().
Up to microblaze maintainers...
[folded a fix from Michal]
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Only one caller hasn't done it in assembler - work_pending on !MMU.
Everything else can't reach do_notify_resume() if we are returning
to kernel mode, so move that check to that sole caller and make
do_notify_resume() reachable only when returning to userland.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
It's been a dead code since commit 571202f50f
Author: Michal Simek <monstr@monstr.eu>
Date: Fri Dec 11 12:54:04 2009 +0100
microblaze: Remove rt_sigsuspend wrapper
Generic rt_sigsuspend syscalls doesn't need any asm wrapper.
but that commit has only removed it from entry.S, missing one in entry-nommu.S.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
"la" pseudo instruction is only translation to "addik".
Use directly "addik" which is described in the MB reference guide.
Signed-off-by: Michal Simek <monstr@monstr.eu>
Implement intelligent backtracing by searching for stack frame creation,
and emitting only return addresses. Use print_hex_dump() to display the
entire binary kernel stack.
Limitation: MMU kernels are not currently able to trace beyond a system trap
(interrupt, syscall, etc.). It is the intent of this patch to provide
infrastructure that can be extended to add this capability later.
Changes from V1:
* Removed checks in find_frame_creation() that prevented location of the frame
creation instruction in heavily optimized code
* Various formatting/commenting/file location tweaks per review comments
* Dropped Kconfig option to enable STACKTRACE as something logically separate
Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
schedule() should not be called with interrupts disabled.
Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
Interrupts must be disabled while an interrupt state restore
(prep for interrupt return) is in progress.
Code to do this was lost in the port to the mainline kernel.
Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
The noMMU syscall trap has a bug that causes R11 to be zero on return to
userland. Remove the extra "save" of R11 responsible for the bug.
Remove reloading of mode indicator because r11 already contains it.
Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
The prototypes in syscalls.h all make sense for
microblaze, but for some of them, the actual implementation
in sys_microblaze.c needs to be adapted.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michal Simek <monstr@monstr.eu>
When legacy signal handling is disabled, the
arch/microblaze/kernel/signal.c implementation can
be much simpler, as most of it is handled generically
from kernel/signal.c.
This is also a prerequisite for using the generic
asm/unistd.h, which does not provide __NR_sigreturn,
because this macro is referenced by the current signal.c
implementation.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michal Simek <monstr@monstr.eu>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Stephen Neuendorffer <stephen.neuendorffer@xilinx.com>
Acked-by: John Linn <john.linn@xilinx.com>
Acked-by: John Williams <john.williams@petalogix.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
Al Viro