On 23/08/2015 17:23, Emilio G. Cota wrote:
> Otherwise after an exception we end up in a deadlock.
Can you explain better the path that exits cpu_exec with the lock taken?
Also, let's remove the recursive locking by introducing "mmap_lock()
already taken" variants of target_mprotect and target_mmap.
Paolo
> Signed-off-by: Emilio G. Cota <c...@braap.org>
> ---
> 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)
> {
>
