[PATCH] linux-user: main: Let each env have its own gdt table

[chengang]

From: Chen Gang <cheng...@emindsoft.com.cn>

It is a temporary fix for thread LTS which need switch the ldt related
index in gdt table for stable-4.1 branch.

Welcome anyone providing the complete fix.

Signed-off-by: Chen Gang <cheng...@emindsoft.com.cn>
---
 linux-user/main.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/linux-user/main.c b/linux-user/main.c
index 8ffc525195..cad261fc7b 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -194,12 +194,17 @@ CPUArchState *cpu_copy(CPUArchState *env)
     CPUArchState *new_env = new_cpu->env_ptr;
     CPUBreakpoint *bp;
     CPUWatchpoint *wp;
+    int size = sizeof(uint64_t) * TARGET_GDT_ENTRIES;
 
     /* Reset non arch specific state */
     cpu_reset(new_cpu);
 
     memcpy(new_env, env, sizeof(CPUArchState));
 
+    new_env->gdt.base = target_mmap(0, size, PROT_READ | PROT_WRITE,
+                                     MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+    memcpy(g2h(new_env->gdt.base), g2h(env->gdt.base), size);
+
     /* Clone all break/watchpoints.
        Note: Once we support ptrace with hw-debug register access, make sure
        BP_CPU break/watchpoints are handled correctly on clone. */
-- 
2.24.0.308.g228f53135a