Commit Graph

13 Commits

Author SHA1 Message Date
Richard Henderson 0a99f09383 linux-user: Split out helpers for sigsuspend
Two new functions: process_sigsuspend_mask and finish_sigsuspend_mask.
Move the size check and copy-from-user code.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20220315084308.433109-3-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2022-03-22 13:06:21 +01:00
Peter Maydell 337e88d890 linux-user: Return void from queue_signal()
The linux-user queue_signal() function always returns 1, and none of
its callers check the return value.  Give it a void return type
instead.

The return value is a leftover from the old pre-2016 linux-user
signal handling code, which really did have a queue of signals and so
might return a failure indication if too many signals were queued at
once.  The current design avoids having to ever have more than one
signal queued via queue_signal() at once, so it can never fail.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220114153732.3767229-4-peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2022-01-18 12:42:28 +01:00
Richard Henderson 5da4063f64 linux-user: Create special-errno.h
Pull the two internal errno used by qemu internally into their own
header file.  This includes the one define required by safe-syscall.S.

Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-12-19 20:47:33 -08:00
Richard Henderson af254a2792 linux-user: Rename TARGET_ERESTARTSYS to QEMU_ERESTARTSYS
This value is fully internal to qemu, and so is not a TARGET define.
We use this as an extra marker for both host and target errno.

Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-12-19 20:47:33 -08:00
Richard Henderson db2af69d6b linux-user: Add infrastructure for a signal trampoline page
Allocate a page to hold the signal trampoline(s).
Invoke a guest-specific hook to fill in the contents
of the page before marking it read-execute again.

Reviewed-by: Max Filippov <jcmvbkbc@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210929130553.121567-2-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2021-10-01 12:03:47 +02:00
Peter Maydell af7969605e linux-user: Provide new force_sig_fault() function
In many places in the linux-user code we need to queue a signal for
the guest using the QEMU_SI_FAULT si_type.  This requires that the
caller sets up and passes us a target_siginfo, including setting the
appropriate part of the _sifields union for the si_type. In a number
of places the code forgets to set the _sifields union field.

Provide a new force_sig_fault() function, which does the same thing
as the Linux kernel function of that name -- it takes the signal
number, the si_code value and the address to use in
_sifields._sigfault, and assembles the target_siginfo itself.  This
makes the callsites simpler and means it's harder to forget to pass
in an address value.

We follow force_sig() and the kernel's force_sig_fault() in not
requiring the caller to pass in the CPU pointer but always acting
on the CPU of the current thread.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210813131809.28655-6-peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2021-09-23 14:42:55 +02:00
Peter Maydell 2113aed687 linux-user: Split signal-related prototypes into signal-common.h
Split the signal related prototypes into the existing header file
signal-common.h, and include it in those places that now require it.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210908154405.15417-4-peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2021-09-13 20:35:44 +02:00
Richard Henderson ddc3e74d9c linux-user: Pass CPUArchState to target_restore_altstack
In most cases we were already passing get_sp_from_cpustate
directly to the function.  In other cases, we were passing
a local variable which already contained the same value.
In the rest of the cases, we were passing the stack pointer
out of env directly.

Reviewed by: Warner Losh <imp@bsdimp.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210426025334.1168495-5-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2021-05-15 21:43:23 +02:00
Richard Henderson 92bad94836 linux-user: Split out target_restore_altstack
Create a function to match target_save_altstack.
Fix some style and unlock issues in do_sigaltstack.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210426025334.1168495-2-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2021-05-15 21:43:23 +02:00
Peter Maydell 5bfce0b74f linux-user: Make sigaltstack stacks per-thread
The alternate signal stack set up by the sigaltstack syscall is
supposed to be per-thread.  We were incorrectly implementing it as
process-wide.  This causes problems for guest binaries that rely on
this.  Notably the Go runtime does, and so we were seeing crashes
caused by races where two guest threads might incorrectly both
execute on the same stack simultaneously.

Replace the global target_sigaltstack_used with a field
sigaltstack_used in the TaskState, and make all the references to the
old global instead get a pointer to the TaskState and use the field.

Fixes: https://bugs.launchpad.net/qemu/+bug/1696773
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20190725131645.19501-1-peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2019-07-26 19:24:33 +02:00
Laurent Vivier 465e237bf7 linux-user: introduce target_sigsp() and target_save_altstack()
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20180411192347.30228-1-laurent@vivier.eu>
2018-05-03 18:29:15 +02:00
Laurent Vivier cb6ac802ef linux-user: define TARGET_ARCH_HAS_SETUP_FRAME
Instead of calling setup_frame() conditionally to a list of known targets,
define TARGET_ARCH_HAS_SETUP_FRAME if the target provides the function
and call it only if the macro is defined.

Move declarations of setup_frame() and setup_rt_frame() to
linux-user/signal-common.h

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20180424192635.6027-21-laurent@vivier.eu>
2018-04-30 09:47:47 +02:00
Laurent Vivier befb7447a0 linux-user: create a dummy per arch signal.c
Create a signal-common.h for future use by these new files
and use it in the existing signal.c

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20180424192635.6027-2-laurent@vivier.eu>
2018-04-30 09:47:47 +02:00