Keep track of the new child tidptr given by a set_tid_address() syscall.

Signed-off-by: Helge Deller <deller@gmx.de>

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index f65045efe6..fdf5c1c03e 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -12202,7 +12202,11 @@ static abi_long do_syscall1(void *cpu_env, int num, abi_long arg1,

 #if defined(TARGET_NR_set_tid_address) && defined(__NR_set_tid_address)
     case TARGET_NR_set_tid_address:
-        return get_errno(set_tid_address((int *)g2h(cpu, arg1)));
+    {
+        TaskState *ts = cpu->opaque;
+        ts->child_tidptr = arg1;
+        return get_errno(set_tid_address((int *)g2h(cpu, ts->child_tidptr)));
+    }
 #endif

     case TARGET_NR_tkill:

I think the previous patch was wrong, since we just emulate writing to
child_tidptr. Below is updated RFC patch.

---
[PATCH] linux-user: Adjust child_tidptr on set_tid_address()

Keep track of the new child tidptr given by a set_tid_address() syscall.

Signed-off-by: Helge Deller <deller@gmx.de>

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index f65045efe6..9114c611a0 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -320,9 +320,6 @@ _syscall3(int,sys_syslog,int,type,char*,bufp,int,len)
 #ifdef __NR_exit_group
 _syscall1(int,exit_group,int,error_code)
 #endif
-#if defined(TARGET_NR_set_tid_address) && defined(__NR_set_tid_address)
-_syscall1(int,set_tid_address,int *,tidptr)
-#endif
 #if defined(__NR_futex)
 _syscall6(int,sys_futex,int *,uaddr,int,op,int,val,
           const struct timespec *,timeout,int *,uaddr2,int,val3)
@@ -12200,9 +12197,14 @@ static abi_long do_syscall1(void *cpu_env, int num, abi_long arg1,
     }
 #endif

-#if defined(TARGET_NR_set_tid_address) && defined(__NR_set_tid_address)
+#if defined(TARGET_NR_set_tid_address)
     case TARGET_NR_set_tid_address:
-        return get_errno(set_tid_address((int *)g2h(cpu, arg1)));
+    {
+        TaskState *ts = cpu->opaque;
+        ts->child_tidptr = arg1;
+        /* do not call host set_tid_address() syscall, instead return tid() */
+        return get_errno(sys_gettid());
+    }
 #endif

     case TARGET_NR_tkill:

On 5/27/22 13:44, Helge Deller wrote:
> I think the previous patch was wrong, since we just emulate writing to
> child_tidptr. Below is updated RFC patch.
> 
> ---
> [PATCH] linux-user: Adjust child_tidptr on set_tid_address()
> 
> Keep track of the new child tidptr given by a set_tid_address() syscall.
> 
> Signed-off-by: Helge Deller<deller@gmx.de>

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~