[Xen-changelog] [xen master] xen/arm: vcpu: Correctly release resources when a VCPU fails to initialize

[patchbot@xxxxxxx]

commit 911232f02a637f65726d9f7cf7f480f34786b8e1
Author:     Julien Grall <julien.grall@xxxxxxxxxx>
AuthorDate: Wed Apr 30 20:15:55 2014 +0100
Commit:     Ian Campbell <ian.campbell@xxxxxxxxxx>
CommitDate: Mon Jun 2 14:38:12 2014 +0100

    xen/arm: vcpu: Correctly release resources when a VCPU fails to initialize
    
    While I was adding new failing code at the end of the function, I noticed
    that the vtimers are not freed which messes up all the timers and will crash
    Xen quickly when the page s reused.
    
    Currently neither vcpu_vgic_init nor vcpu_vtimer_init fails, so we
    are safe for now. With the new GICv3 code, the former function will be able
    to fail. This will result in a memory leak.
    
    Call vcpu_destroy if the initialization has failed. We also need to add a
    boolean to know if the vtimers are correctly setup as the timer common code
    doesn't have any safeguard against removing a non-initialized timer.
    
    Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx>
    Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
---
 xen/arch/arm/domain.c        |    8 ++++++--
 xen/arch/arm/vtimer.c        |    5 +++++
 xen/include/asm-arm/domain.h |    1 +
 3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
index 2ae6941..04d0cd0 100644
--- a/xen/arch/arm/domain.c
+++ b/xen/arch/arm/domain.c
@@ -470,12 +470,16 @@ int vcpu_initialise(struct vcpu *v)
     processor_vcpu_initialise(v);
 
     if ( (rc = vcpu_vgic_init(v)) != 0 )
-        return rc;
+        goto fail;
 
     if ( (rc = vcpu_vtimer_init(v)) != 0 )
-        return rc;
+        goto fail;
 
     return rc;
+
+fail:
+    vcpu_destroy(v);
+    return rc;
 }
 
 void vcpu_destroy(struct vcpu *v)
diff --git a/xen/arch/arm/vtimer.c b/xen/arch/arm/vtimer.c
index b93153e..7b50826 100644
--- a/xen/arch/arm/vtimer.c
+++ b/xen/arch/arm/vtimer.c
@@ -77,11 +77,16 @@ int vcpu_vtimer_init(struct vcpu *v)
         : GUEST_TIMER_VIRT_PPI;
     t->v = v;
 
+    v->arch.vtimer_initialized = 1;
+
     return 0;
 }
 
 void vcpu_timer_destroy(struct vcpu *v)
 {
+    if ( !v->arch.vtimer_initialized )
+        return;
+
     kill_timer(&v->arch.virt_timer.timer);
     kill_timer(&v->arch.phys_timer.timer);
 }
diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
index b296923..f6cb1c0 100644
--- a/xen/include/asm-arm/domain.h
+++ b/xen/include/asm-arm/domain.h
@@ -289,6 +289,7 @@ struct arch_vcpu
 
     struct vtimer phys_timer;
     struct vtimer virt_timer;
+    bool_t vtimer_initialized;
 }  __cacheline_aligned;
 
 void vcpu_show_execution_state(struct vcpu *);
--
generated by git-patchbot for /home/xen/git/xen.git#master

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