[PATCH v2 05/18] exec: Fix file_ram_alloc() error API violations

Markus Armbruster posted 18 patches 6 years, 2 months ago
Maintainers: Igor Mammedov <imammedo@redhat.com>, Christian Borntraeger <borntraeger@de.ibm.com>, Paolo Bonzini <pbonzini@redhat.com>, Corey Minyard <minyard@acm.org>, Markus Armbruster <armbru@redhat.com>, Paul Burton <pburton@wavecomp.com>, Michael Roth <mdroth@linux.vnet.ibm.com>, Cornelia Huck <cohuck@redhat.com>, David Hildenbrand <david@redhat.com>, David Gibson <david@gibson.dropbear.id.au>, "Michael S. Tsirkin" <mst@redhat.com>, Aleksandar Rikalo <aleksandar.rikalo@rt-rk.com>, Halil Pasic <pasic@linux.ibm.com>, "Daniel P. Berrangé" <berrange@redhat.com>, Richard Henderson <rth@twiddle.net>
[PATCH v2 05/18] exec: Fix file_ram_alloc() error API violations
Posted by Markus Armbruster 6 years, 2 months ago
When os_mem_prealloc() fails, file_ram_alloc() calls qemu_ram_munmap()
and returns null.  Except it doesn't when its @errp argument is null,
because it checks for failure with (errp && *errp).  Introduced in
commit 056b68af77 "fix qemu exit on memory hotplug when allocation
fails at prealloc time".

No caller actually passes null.

Fix anyway: splice in a local Error *err, and error_propagate().

Cc: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
---
 exec.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/exec.c b/exec.c
index ffdb518535..45695a5f2d 100644
--- a/exec.c
+++ b/exec.c
@@ -1841,6 +1841,7 @@ static void *file_ram_alloc(RAMBlock *block,
                             bool truncate,
                             Error **errp)
 {
+    Error *err = NULL;
     MachineState *ms = MACHINE(qdev_get_machine());
     void *area;
 
@@ -1898,8 +1899,9 @@ static void *file_ram_alloc(RAMBlock *block,
     }
 
     if (mem_prealloc) {
-        os_mem_prealloc(fd, area, memory, ms->smp.cpus, errp);
-        if (errp && *errp) {
+        os_mem_prealloc(fd, area, memory, ms->smp.cpus, &err);
+        if (err) {
+            error_propagate(errp, err);
             qemu_ram_munmap(fd, area, memory);
             return NULL;
         }
-- 
2.21.0


Re: [PATCH v2 05/18] exec: Fix file_ram_alloc() error API violations
Posted by Philippe Mathieu-Daudé 6 years, 2 months ago
On 12/4/19 10:36 AM, Markus Armbruster wrote:
> When os_mem_prealloc() fails, file_ram_alloc() calls qemu_ram_munmap()
> and returns null.  Except it doesn't when its @errp argument is null,
> because it checks for failure with (errp && *errp).  Introduced in
> commit 056b68af77 "fix qemu exit on memory hotplug when allocation
> fails at prealloc time".
> 
> No caller actually passes null.
> 
> Fix anyway: splice in a local Error *err, and error_propagate().
> 
> Cc: Igor Mammedov <imammedo@redhat.com>
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> Reviewed-by: Igor Mammedov <imammedo@redhat.com>

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

> ---
>   exec.c | 6 ++++--
>   1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/exec.c b/exec.c
> index ffdb518535..45695a5f2d 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -1841,6 +1841,7 @@ static void *file_ram_alloc(RAMBlock *block,
>                               bool truncate,
>                               Error **errp)
>   {
> +    Error *err = NULL;
>       MachineState *ms = MACHINE(qdev_get_machine());
>       void *area;
>   
> @@ -1898,8 +1899,9 @@ static void *file_ram_alloc(RAMBlock *block,
>       }
>   
>       if (mem_prealloc) {
> -        os_mem_prealloc(fd, area, memory, ms->smp.cpus, errp);
> -        if (errp && *errp) {
> +        os_mem_prealloc(fd, area, memory, ms->smp.cpus, &err);
> +        if (err) {
> +            error_propagate(errp, err);
>               qemu_ram_munmap(fd, area, memory);
>               return NULL;
>           }
>