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authorPaolo Bonzini <pbonzini@redhat.com>2023-06-17 01:01:29 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2023-06-26 10:23:56 +0200
commit63fd8ef080351357c0cb0644ed63fd3e2a8833a8 (patch)
tree91481e0107c3a469373c997a838c7796d71fd2f5 /linux-user/i386
parent6750485bf42a9917a29487aec899687669104e07 (diff)
target/i386: implement SYSCALL/SYSRET in 32-bit emulators
AMD supports both 32-bit and 64-bit SYSCALL/SYSRET, but the TCG only exposes it for 64-bit targets. For system emulation just reuse the helper; for user-mode emulation the ABI is the same as "int $80". The BSDs does not support any fast system call mechanism in 32-bit mode so add to bsd-user the same stub that FreeBSD has for 64-bit compatibility mode. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'linux-user/i386')
-rw-r--r--linux-user/i386/cpu_loop.c9
1 files changed, 5 insertions, 4 deletions
diff --git a/linux-user/i386/cpu_loop.c b/linux-user/i386/cpu_loop.c
index 2d0918a93f..9eeda551ea 100644
--- a/linux-user/i386/cpu_loop.c
+++ b/linux-user/i386/cpu_loop.c
@@ -211,6 +211,9 @@ void cpu_loop(CPUX86State *env)
switch(trapnr) {
case 0x80:
+#ifndef TARGET_X86_64
+ case EXCP_SYSCALL:
+#endif
/* linux syscall from int $0x80 */
ret = do_syscall(env,
env->regs[R_EAX],
@@ -227,9 +230,9 @@ void cpu_loop(CPUX86State *env)
env->regs[R_EAX] = ret;
}
break;
-#ifndef TARGET_ABI32
+#ifdef TARGET_X86_64
case EXCP_SYSCALL:
- /* linux syscall from syscall instruction */
+ /* linux syscall from syscall instruction. */
ret = do_syscall(env,
env->regs[R_EAX],
env->regs[R_EDI],
@@ -245,8 +248,6 @@ void cpu_loop(CPUX86State *env)
env->regs[R_EAX] = ret;
}
break;
-#endif
-#ifdef TARGET_X86_64
case EXCP_VSYSCALL:
emulate_vsyscall(env);
break;