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[Qemu-devel] [PATCH v2 06/28] linux-user: Support for restarting system
From: |
Peter Maydell |
Subject: |
[Qemu-devel] [PATCH v2 06/28] linux-user: Support for restarting system calls for x86 targets |
Date: |
Thu, 12 May 2016 18:47:30 +0100 |
From: Timothy E Baldwin <address@hidden>
Update the x86 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 rather than passing it
back out as the "return code" from do_sigreturn()
* handle TARGET_QEMU_ESIGRETURN in the main loop as the indication
that the main loop should not touch EAX
Signed-off-by: Timothy Edward Baldwin <address@hidden>
Message-id: address@hidden
Reviewed-by: Peter Maydell <address@hidden>
[PMM: Commit message tweaks; drop TARGET_USE_ERESTARTSYS define]
Signed-off-by: Peter Maydell <address@hidden>
---
linux-user/main.c | 47 +++++++++++++++++++++++++++++------------------
linux-user/signal.c | 15 +++++++--------
linux-user/syscall.c | 2 --
3 files changed, 36 insertions(+), 28 deletions(-)
diff --git a/linux-user/main.c b/linux-user/main.c
index 5f3ec97..a207888 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -284,6 +284,7 @@ void cpu_loop(CPUX86State *env)
CPUState *cs = CPU(x86_env_get_cpu(env));
int trapnr;
abi_ulong pc;
+ abi_ulong ret;
target_siginfo_t info;
for(;;) {
@@ -293,28 +294,38 @@ void cpu_loop(CPUX86State *env)
switch(trapnr) {
case 0x80:
/* linux syscall from int $0x80 */
- env->regs[R_EAX] = do_syscall(env,
- env->regs[R_EAX],
- env->regs[R_EBX],
- env->regs[R_ECX],
- env->regs[R_EDX],
- env->regs[R_ESI],
- env->regs[R_EDI],
- env->regs[R_EBP],
- 0, 0);
+ ret = do_syscall(env,
+ env->regs[R_EAX],
+ env->regs[R_EBX],
+ env->regs[R_ECX],
+ env->regs[R_EDX],
+ env->regs[R_ESI],
+ env->regs[R_EDI],
+ env->regs[R_EBP],
+ 0, 0);
+ if (ret == -TARGET_ERESTARTSYS) {
+ env->eip -= 2;
+ } else if (ret != -TARGET_QEMU_ESIGRETURN) {
+ env->regs[R_EAX] = ret;
+ }
break;
#ifndef TARGET_ABI32
case EXCP_SYSCALL:
/* linux syscall from syscall instruction */
- env->regs[R_EAX] = do_syscall(env,
- env->regs[R_EAX],
- env->regs[R_EDI],
- env->regs[R_ESI],
- env->regs[R_EDX],
- env->regs[10],
- env->regs[8],
- env->regs[9],
- 0, 0);
+ ret = do_syscall(env,
+ env->regs[R_EAX],
+ env->regs[R_EDI],
+ env->regs[R_ESI],
+ env->regs[R_EDX],
+ env->regs[10],
+ env->regs[8],
+ env->regs[9],
+ 0, 0);
+ if (ret == -TARGET_ERESTARTSYS) {
+ env->eip -= 2;
+ } else if (ret != -TARGET_QEMU_ESIGRETURN) {
+ env->regs[R_EAX] = ret;
+ }
break;
#endif
case EXCP0B_NOSEG:
diff --git a/linux-user/signal.c b/linux-user/signal.c
index 04c21d0..11ddd05 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -1024,7 +1024,7 @@ give_sigsegv:
}
static int
-restore_sigcontext(CPUX86State *env, struct target_sigcontext *sc, int *peax)
+restore_sigcontext(CPUX86State *env, struct target_sigcontext *sc)
{
unsigned int err = 0;
abi_ulong fpstate_addr;
@@ -1042,6 +1042,7 @@ restore_sigcontext(CPUX86State *env, struct
target_sigcontext *sc, int *peax)
env->regs[R_EBX] = tswapl(sc->ebx);
env->regs[R_EDX] = tswapl(sc->edx);
env->regs[R_ECX] = tswapl(sc->ecx);
+ env->regs[R_EAX] = tswapl(sc->eax);
env->eip = tswapl(sc->eip);
cpu_x86_load_seg(env, R_CS, lduw_p(&sc->cs) | 3);
@@ -1059,7 +1060,6 @@ restore_sigcontext(CPUX86State *env, struct
target_sigcontext *sc, int *peax)
cpu_x86_frstor(env, fpstate_addr, 1);
}
- *peax = tswapl(sc->eax);
return err;
badframe:
return 1;
@@ -1071,7 +1071,7 @@ long do_sigreturn(CPUX86State *env)
abi_ulong frame_addr = env->regs[R_ESP] - 8;
target_sigset_t target_set;
sigset_t set;
- int eax, i;
+ int i;
trace_user_do_sigreturn(env, frame_addr);
if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1))
@@ -1086,10 +1086,10 @@ long do_sigreturn(CPUX86State *env)
do_sigprocmask(SIG_SETMASK, &set, NULL);
/* restore registers */
- if (restore_sigcontext(env, &frame->sc, &eax))
+ if (restore_sigcontext(env, &frame->sc))
goto badframe;
unlock_user_struct(frame, frame_addr, 0);
- return eax;
+ return -TARGET_QEMU_ESIGRETURN;
badframe:
unlock_user_struct(frame, frame_addr, 0);
@@ -1102,7 +1102,6 @@ long do_rt_sigreturn(CPUX86State *env)
abi_ulong frame_addr;
struct rt_sigframe *frame;
sigset_t set;
- int eax;
frame_addr = env->regs[R_ESP] - 4;
trace_user_do_rt_sigreturn(env, frame_addr);
@@ -1111,7 +1110,7 @@ long do_rt_sigreturn(CPUX86State *env)
target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
do_sigprocmask(SIG_SETMASK, &set, NULL);
- if (restore_sigcontext(env, &frame->uc.tuc_mcontext, &eax)) {
+ if (restore_sigcontext(env, &frame->uc.tuc_mcontext)) {
goto badframe;
}
@@ -1121,7 +1120,7 @@ long do_rt_sigreturn(CPUX86State *env)
}
unlock_user_struct(frame, frame_addr, 0);
- return eax;
+ return -TARGET_QEMU_ESIGRETURN;
badframe:
unlock_user_struct(frame, frame_addr, 0);
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index f4c2e19..a4a1af7 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -6940,12 +6940,10 @@ abi_long do_syscall(void *cpu_env, int num, abi_long
arg1,
break;
#ifdef TARGET_NR_sigreturn
case TARGET_NR_sigreturn:
- /* NOTE: ret is eax, so not transcoding must be done */
ret = do_sigreturn(cpu_env);
break;
#endif
case TARGET_NR_rt_sigreturn:
- /* NOTE: ret is eax, so not transcoding must be done */
ret = do_rt_sigreturn(cpu_env);
break;
case TARGET_NR_sethostname:
--
1.9.1
- [Qemu-devel] [PATCH v2 15/28] linux-user: Support for restarting system calls for M68K targets, (continued)
- [Qemu-devel] [PATCH v2 15/28] linux-user: Support for restarting system calls for M68K targets, Peter Maydell, 2016/05/12
- [Qemu-devel] [PATCH v2 01/28] linux-user: Check array bounds in errno conversion, Peter Maydell, 2016/05/12
- [Qemu-devel] [PATCH v2 18/28] linux-user: Support for restarting system calls for tilegx targets, Peter Maydell, 2016/05/12
- [Qemu-devel] [PATCH v2 20/28] linux-user: Support for restarting system calls for Microblaze targets, Peter Maydell, 2016/05/12
- [Qemu-devel] [PATCH v2 25/28] linux-user: Use safe_syscall for wait system calls, Peter Maydell, 2016/05/12
- [Qemu-devel] [PATCH v2 07/28] linux-user: Support for restarting system calls for ARM targets, Peter Maydell, 2016/05/12
- [Qemu-devel] [PATCH v2 13/28] linux-user: Support for restarting system calls for UniCore32 targets, Peter Maydell, 2016/05/12
- [Qemu-devel] [PATCH v2 04/28] linux-user: Define TARGET_ERESTART* errno values, Peter Maydell, 2016/05/12
- [Qemu-devel] [PATCH v2 22/28] linux-user: Provide safe_syscall for fixing races between signals and syscalls, Peter Maydell, 2016/05/12
- [Qemu-devel] [PATCH v2 06/28] linux-user: Support for restarting system calls for x86 targets,
Peter Maydell <=
- [Qemu-devel] [PATCH v2 02/28] linux-user: Consistently return host errnos from do_openat(), Peter Maydell, 2016/05/12
- [Qemu-devel] [PATCH v2 27/28] linux-user: Use safe_syscall for pselect, select syscalls, Peter Maydell, 2016/05/12
- [Qemu-devel] [PATCH v2 24/28] linux-user: Use safe_syscall for open and openat system calls, Peter Maydell, 2016/05/12
- [Qemu-devel] [PATCH v2 14/28] linux-user: Support for restarting system calls for OpenRISC targets, Peter Maydell, 2016/05/12
- [Qemu-devel] [PATCH v2 19/28] linux-user: Set r14 on exit from microblaze syscall, Peter Maydell, 2016/05/12
- [Qemu-devel] [PATCH v2 12/28] linux-user: Support for restarting system calls for Alpha targets, Peter Maydell, 2016/05/12
- [Qemu-devel] [PATCH v2 23/28] linux-user: Use safe_syscall for read and write system calls, Peter Maydell, 2016/05/12
- [Qemu-devel] [PATCH v2 08/28] linux-user: Support for restarting system calls for MIPS targets, Peter Maydell, 2016/05/12
- [Qemu-devel] [PATCH v2 16/28] linux-user: Support for restarting system calls for S390 targets, Peter Maydell, 2016/05/12