diff options
| author | Timothy E Baldwin <T.E.Baldwin99@members.leeds.ac.uk> | 2016-05-12 18:47:44 +0100 |
|---|---|---|
| committer | Riku Voipio <riku.voipio@linaro.org> | 2016-05-27 14:49:51 +0300 |
| commit | 4134ecfeb903c362558cb1cb594ff532fd83fb84 (patch) | |
| tree | 625495096eed337f3899d84187c5228e39f53d56 /linux-user | |
| parent | d7749ab770601258be7ae862b5827c42bb35e44c (diff) | |
linux-user: Support for restarting system calls for Microblaze targets
Update the Microblaze main loop and sigreturn code:
* on TARGET_ERESTARTSYS, wind guest PC backwards to repeat syscall insn
* set all guest CPU state within signal.c code on sigreturn
* handle TARGET_QEMU_ESIGRETURN in the main loop as the indication
that the main loop should not touch any guest CPU state
Note that this in passing fixes a bug where we were corrupting
the guest r[3] on sigreturn with the guest's r[10] because
do_sigreturn() was returning env->regs[10] but the register for
syscall return values is env->regs[3].
Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-11-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
[PMM: Commit message tweaks; drop TARGET_USE_ERESTARTSYS define;
drop whitespace changes]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Diffstat (limited to 'linux-user')
| -rw-r--r-- | linux-user/main.c | 7 | ||||
| -rw-r--r-- | linux-user/microblaze/target_signal.h | 1 | ||||
| -rw-r--r-- | linux-user/signal.c | 2 |
3 files changed, 8 insertions, 2 deletions
diff --git a/linux-user/main.c b/linux-user/main.c index c5da418fa4..b2bc6ab2f7 100644 --- a/linux-user/main.c +++ b/linux-user/main.c @@ -2982,7 +2982,12 @@ void cpu_loop(CPUMBState *env) env->regs[9], env->regs[10], 0, 0); - env->regs[3] = ret; + if (ret == -TARGET_ERESTARTSYS) { + /* Wind back to before the syscall. */ + env->sregs[SR_PC] -= 4; + } else if (ret != -TARGET_QEMU_ESIGRETURN) { + env->regs[3] = ret; + } /* All syscall exits result in guest r14 being equal to the * PC we return to, because the kernel syscall exit "rtbd" does * this. (This is true even for sigreturn(); note that r14 is diff --git a/linux-user/microblaze/target_signal.h b/linux-user/microblaze/target_signal.h index 3d1f7a7238..acdf3b5acd 100644 --- a/linux-user/microblaze/target_signal.h +++ b/linux-user/microblaze/target_signal.h @@ -26,4 +26,5 @@ static inline abi_ulong get_sp_from_cpustate(CPUMBState *state) return state->regs[14]; } + #endif /* TARGET_SIGNAL_H */ diff --git a/linux-user/signal.c b/linux-user/signal.c index b4641dffb8..9e8555096a 100644 --- a/linux-user/signal.c +++ b/linux-user/signal.c @@ -3618,7 +3618,7 @@ long do_sigreturn(CPUMBState *env) env->regs[14] = env->sregs[SR_PC]; unlock_user_struct(frame, frame_addr, 0); - return env->regs[10]; + return -TARGET_QEMU_ESIGRETURN; badframe: force_sig(TARGET_SIGSEGV); } |