[Qemu-devel] [RFC 24/38] cpu-exec: reset mmap_lock after exiting the CPU loop

[Emilio G. Cota]

Otherwise after an exception we end up in a deadlock.

Signed-off-by: Emilio G. Cota <address@hidden>
---
 bsd-user/mmap.c         | 12 ++++++++++++
 cpu-exec.c              |  1 +
 include/exec/exec-all.h |  2 ++
 linux-user/mmap.c       |  8 ++++++++
 4 files changed, 23 insertions(+)

diff --git a/bsd-user/mmap.c b/bsd-user/mmap.c
index 092bf7f..b37a8f5 100644
--- a/bsd-user/mmap.c
+++ b/bsd-user/mmap.c
@@ -48,6 +48,14 @@ void mmap_unlock(void)
     }
 }
 
+void mmap_lock_reset(void)
+{
+    while (mmap_lock_count) {
+        mmap_lock_count--;
+        pthread_mutex_unlock(&mmap_mutex);
+    }
+}
+
 /* Grab lock to make sure things are in a consistent state after fork().  */
 void mmap_fork_start(void)
 {
@@ -72,6 +80,10 @@ void mmap_lock(void)
 void mmap_unlock(void)
 {
 }
+
+void mmap_lock_reset(void)
+{
+}
 #endif
 
 /* NOTE: all the constants are the HOST ones, but addresses are target. */
diff --git a/cpu-exec.c b/cpu-exec.c
index a1700ac..f758928 100644
--- a/cpu-exec.c
+++ b/cpu-exec.c
@@ -630,6 +630,7 @@ int cpu_exec(CPUState *cpu)
             env = &x86_cpu->env;
 #endif
             tb_lock_reset();
+            mmap_lock_reset();
             cpu_exit_loop_lock_reset(cpu);
         }
     } /* for(;;) */
diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
index b1934bf..3b8399a 100644
--- a/include/exec/exec-all.h
+++ b/include/exec/exec-all.h
@@ -334,6 +334,7 @@ void tlb_fill(CPUState *cpu, target_ulong addr, int 
is_write, int mmu_idx,
 #if defined(CONFIG_USER_ONLY)
 void mmap_lock(void);
 void mmap_unlock(void);
+void mmap_lock_reset(void);
 
 static inline tb_page_addr_t get_page_addr_code(CPUArchState *env1, 
target_ulong addr)
 {
@@ -342,6 +343,7 @@ static inline tb_page_addr_t 
get_page_addr_code(CPUArchState *env1, target_ulong
 #else
 static inline void mmap_lock(void) {}
 static inline void mmap_unlock(void) {}
+static inline void mmap_lock_reset(void) {}
 
 /* cputlb.c */
 tb_page_addr_t get_page_addr_code(CPUArchState *env1, target_ulong addr);
diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index 78e1b2d..8ee80f5 100644
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -51,6 +51,14 @@ void mmap_unlock(void)
     }
 }
 
+void mmap_lock_reset(void)
+{
+    if (mmap_lock_count) {
+        mmap_lock_count = 0;
+        pthread_mutex_unlock(&mmap_mutex);
+    }
+}
+
 /* Grab lock to make sure things are in a consistent state after fork().  */
 void mmap_fork_start(void)
 {
-- 
1.9.1