Commit 05306935 authored by Fei Li's avatar Fei Li Committed by Dr. David Alan Gilbert
Browse files

migration: fix the compression code 



Add judgement in compress_threads_save_cleanup() to check whether the
static CompressParam *comp_param has been allocated. If not, just
return; or else segmentation fault will occur when using the NULL
comp_param's parameters.  One test case can reproduce this is: set
the compression on and migrate to a wrong nonexistent host IP address.

Our current code does not judge before handling comp_param[idx]'s quit
and cond that whether they have been initialized. If not initialized,
"qemu_mutex_lock_impl: Assertion `mutex->initialized' failed." will
occur. Fix this by squashing the terminate_compression_threads() into
compress_threads_save_cleanup() and employing the existing judgement
condition.  One test case can reproduce this error is: set the
compression on and fail to fully setup the default eight compression
thread in compress_threads_save_setup().

Signed-off-by: default avatarFei Li <fli@suse.com>
Message-Id: <20180925091440.18910-1-fli@suse.com>
Reviewed-by: default avatarPeter Xu <peterx@redhat.com>
Signed-off-by: default avatarDr. David Alan Gilbert <dgilbert@redhat.com>
parent 0284a2a8

migration/ram.c

+8 −16
Original line number Diff line number Diff line
@@ -431,28 +431,14 @@ static void *do_data_compress(void *opaque) 
    return NULL;

}



static inline void terminate_compression_threads(void)

{

    int idx, thread_count;



    thread_count = migrate_compress_threads();



    for (idx = 0; idx < thread_count; idx++) {

        qemu_mutex_lock(&comp_param[idx].mutex);

        comp_param[idx].quit = true;

        qemu_cond_signal(&comp_param[idx].cond);

        qemu_mutex_unlock(&comp_param[idx].mutex);

    }

}



static void compress_threads_save_cleanup(void)

{

    int i, thread_count;



    if (!migrate_use_compression()) {

    if (!migrate_use_compression() || !comp_param) {

        return;

    }

    terminate_compression_threads();



    thread_count = migrate_compress_threads();

    for (i = 0; i < thread_count; i++) {

        /*
@@ -462,6 +448,12 @@ static void compress_threads_save_cleanup(void) 
        if (!comp_param[i].file) {

            break;

        }



        qemu_mutex_lock(&comp_param[i].mutex);

        comp_param[i].quit = true;

        qemu_cond_signal(&comp_param[i].cond);

        qemu_mutex_unlock(&comp_param[i].mutex);



        qemu_thread_join(compress_threads + i);

        qemu_mutex_destroy(&comp_param[i].mutex);

        qemu_cond_destroy(&comp_param[i].cond);