From: Zhao Liu Date: Mon, 11 Mar 2024 03:38:16 +0000 (+0800) Subject: hw/vfio/pci: Fix missing ERRP_GUARD() for error_prepend() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=cf8afdfad4653ce0c96eb26d660cd86a807dbd86;p=qemu.git hw/vfio/pci: Fix missing ERRP_GUARD() for error_prepend() As the comment in qapi/error, passing @errp to error_prepend() requires ERRP_GUARD(): * = Why, when and how to use ERRP_GUARD() = * * Without ERRP_GUARD(), use of the @errp parameter is restricted: ... * - It should not be passed to error_prepend(), error_vprepend() or * error_append_hint(), because that doesn't work with &error_fatal. * ERRP_GUARD() lifts these restrictions. * * To use ERRP_GUARD(), add it right at the beginning of the function. * @errp can then be used without worrying about the argument being * NULL or &error_fatal. ERRP_GUARD() could avoid the case when @errp is &error_fatal, the user can't see this additional information, because exit() happens in error_setg earlier than information is added [1]. In hw/vfio/pci.c, there are 2 functions passing @errp to error_prepend() without ERRP_GUARD(): - vfio_add_std_cap() - vfio_realize() The @errp of vfio_add_std_cap() is also from vfio_realize(). And vfio_realize(), as a PCIDeviceClass.realize method, its @errp is from DeviceClass.realize so that there is no guarantee that the @errp won't point to @error_fatal. To avoid the issue like [1] said, add missing ERRP_GUARD() at their beginning. [1]: Issue description in the commit message of commit ae7c80a7bd73 ("error: New macro ERRP_GUARD()"). Cc: Alex Williamson Cc: Cédric Le Goater Signed-off-by: Zhao Liu Reviewed-by: Cédric Le Goater Message-ID: <20240311033822.3142585-24-zhao1.liu@linux.intel.com> Signed-off-by: Thomas Huth --- diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c index a1522a011a..64780d1b79 100644 --- a/hw/vfio/pci.c +++ b/hw/vfio/pci.c @@ -2136,6 +2136,7 @@ static void vfio_check_af_flr(VFIOPCIDevice *vdev, uint8_t pos) static int vfio_add_std_cap(VFIOPCIDevice *vdev, uint8_t pos, Error **errp) { + ERRP_GUARD(); PCIDevice *pdev = &vdev->pdev; uint8_t cap_id, next, size; int ret; @@ -2942,6 +2943,7 @@ static void vfio_unregister_req_notifier(VFIOPCIDevice *vdev) static void vfio_realize(PCIDevice *pdev, Error **errp) { + ERRP_GUARD(); VFIOPCIDevice *vdev = VFIO_PCI(pdev); VFIODevice *vbasedev = &vdev->vbasedev; char *tmp, *subsys;