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| author | Michal Privoznik <mprivozn@redhat.com> | 2022-10-26 09:30:24 +0200 |
|---|---|---|
| committer | Daniel P. Berrangé <berrange@redhat.com> | 2022-10-26 13:32:58 +0100 |
| commit | 73422d9524376526ab5950b3be3098901cd605d6 (patch) | |
| tree | 9624968f625979d7ea9d0243ca6b6597baf97512 | |
| parent | 23f77f05f2faa8ff3028fef388322f7b4f09533e (diff) | |
| download | qemu-73422d9524376526ab5950b3be3098901cd605d6.zip qemu-73422d9524376526ab5950b3be3098901cd605d6.tar.gz qemu-73422d9524376526ab5950b3be3098901cd605d6.tar.bz2 | |
seccomp: Get actual errno value from failed seccomp functions
Upon failure, a libseccomp API returns actual errno value very
rarely. Fortunately, after its commit 34bf78ab (contained in
2.5.0 release), the SCMP_FLTATR_API_SYSRAWRC attribute can be set
which makes subsequent APIs return true errno on failure.
This is especially critical when seccomp_load() fails, because
generic -ECANCELED says nothing.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
| -rw-r--r-- | meson.build | 9 | ||||
| -rw-r--r-- | softmmu/qemu-seccomp.c | 13 |
2 files changed, 22 insertions, 0 deletions
diff --git a/meson.build b/meson.build index b686dfe..5f114c8 100644 --- a/meson.build +++ b/meson.build @@ -636,10 +636,16 @@ if vmnet.found() and not cc.has_header_symbol('vmnet/vmnet.h', endif seccomp = not_found +seccomp_has_sysrawrc = false if not get_option('seccomp').auto() or have_system or have_tools seccomp = dependency('libseccomp', version: '>=2.3.0', required: get_option('seccomp'), method: 'pkg-config', kwargs: static_kwargs) + if seccomp.found() + seccomp_has_sysrawrc = cc.has_header_symbol('seccomp.h', + 'SCMP_FLTATR_API_SYSRAWRC', + dependencies: seccomp) + endif endif libcap_ng = not_found @@ -1849,6 +1855,9 @@ config_host_data.set('CONFIG_RDMA', rdma.found()) config_host_data.set('CONFIG_SDL', sdl.found()) config_host_data.set('CONFIG_SDL_IMAGE', sdl_image.found()) config_host_data.set('CONFIG_SECCOMP', seccomp.found()) +if seccomp.found() + config_host_data.set('CONFIG_SECCOMP_SYSRAWRC', seccomp_has_sysrawrc) +endif config_host_data.set('CONFIG_SNAPPY', snappy.found()) config_host_data.set('CONFIG_TPM', have_tpm) config_host_data.set('CONFIG_USB_LIBUSB', libusb.found()) diff --git a/softmmu/qemu-seccomp.c b/softmmu/qemu-seccomp.c index deaf8a4..d66a2a1 100644 --- a/softmmu/qemu-seccomp.c +++ b/softmmu/qemu-seccomp.c @@ -312,6 +312,19 @@ static int seccomp_start(uint32_t seccomp_opts, Error **errp) goto seccomp_return; } +#if defined(CONFIG_SECCOMP_SYSRAWRC) + /* + * This must be the first seccomp_attr_set() call to have full + * error propagation from subsequent seccomp APIs. + */ + rc = seccomp_attr_set(ctx, SCMP_FLTATR_API_SYSRAWRC, 1); + if (rc != 0) { + error_setg_errno(errp, -rc, + "failed to set seccomp rawrc attribute"); + goto seccomp_return; + } +#endif + rc = seccomp_attr_set(ctx, SCMP_FLTATR_CTL_TSYNC, 1); if (rc != 0) { error_setg_errno(errp, -rc, |