On Wed, Aug 10, 2022 at 1:37 PM Tom Lendacky <thomas.lendacky@xxxxxxx> wrote:
>
> On 8/2/22 13:55, Jacky Li wrote:
> > Currently the OS continues the PSP initialization when there is a write
> > failure to the init_ex_file. Therefore, the userspace would be told that
> > SEV is properly INIT'd even though the psp data file is not updated.
> > This is problematic because later when asked for the SEV data, the OS
> > won't be able to provide it.
> >
> > Fixes: 3d725965f836 ("crypto: ccp - Add SEV_INIT_EX support")
> > Reported-by: Peter Gonda <pgonda@xxxxxxxxxx>
> > Signed-off-by: Jacky Li <jackyli@xxxxxxxxxx>
> > ---
> > drivers/crypto/ccp/sev-dev.c | 23 +++++++++++++----------
> > 1 file changed, 13 insertions(+), 10 deletions(-)
> >
> > diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
> > index 5bb2ae250d38..fd6bb01eb198 100644
> > --- a/drivers/crypto/ccp/sev-dev.c
> > +++ b/drivers/crypto/ccp/sev-dev.c
> > @@ -233,7 +233,7 @@ static int sev_read_init_ex_file(void)
> > return 0;
> > }
> >
> > -static void sev_write_init_ex_file(void)
> > +static int sev_write_init_ex_file(void)
> > {
> > struct sev_device *sev = psp_master->sev_data;
> > struct file *fp;
> > @@ -243,14 +243,15 @@ static void sev_write_init_ex_file(void)
> > lockdep_assert_held(&sev_cmd_mutex);
> >
> > if (!sev_init_ex_buffer)
> > - return;
> > + return 0;
> >
> > fp = open_file_as_root(init_ex_path, O_CREAT | O_WRONLY, 0600);
> > if (IS_ERR(fp)) {
> > + int ret = PTR_ERR(fp);
>
> Please put a blank line after the variable declaration.
>
Will do in the v2. Thanks for the reminder!
> > dev_err(sev->dev,
> > "SEV: could not open file for write, error %ld\n",
> > - PTR_ERR(fp));
> > - return;
> > + ret);
>
> You'll need to fix the kernel test robot report here.
>
> Thanks,
> Tom
>
Will change %ld to %d in v2. Thanks!
Thanks,
Jacky
> > + return ret;
> > }
> >
> > nwrite = kernel_write(fp, sev_init_ex_buffer, NV_LENGTH, &offset);
> > @@ -261,18 +262,20 @@ static void sev_write_init_ex_file(void)
> > dev_err(sev->dev,
> > "SEV: failed to write %u bytes to non volatile memory area, ret %ld\n",
> > NV_LENGTH, nwrite);
> > - return;
> > + return -EIO;
> > }
> >
> > dev_dbg(sev->dev, "SEV: write successful to NV file\n");
> > +
> > + return 0;
> > }
> >
> > -static void sev_write_init_ex_file_if_required(int cmd_id)
> > +static int sev_write_init_ex_file_if_required(int cmd_id)
> > {
> > lockdep_assert_held(&sev_cmd_mutex);
> >
> > if (!sev_init_ex_buffer)
> > - return;
> > + return 0;
> >
> > /*
> > * Only a few platform commands modify the SPI/NV area, but none of the
> > @@ -287,10 +290,10 @@ static void sev_write_init_ex_file_if_required(int cmd_id)
> > case SEV_CMD_PEK_GEN:
> > break;
> > default:
> > - return;
> > + return 0;
> > }
> >
> > - sev_write_init_ex_file();
> > + return sev_write_init_ex_file();
> > }
> >
> > static int __sev_do_cmd_locked(int cmd, void *data, int *psp_ret)
> > @@ -363,7 +366,7 @@ static int __sev_do_cmd_locked(int cmd, void *data, int *psp_ret)
> > cmd, reg & PSP_CMDRESP_ERR_MASK);
> > ret = -EIO;
> > } else {
> > - sev_write_init_ex_file_if_required(cmd);
> > + ret = sev_write_init_ex_file_if_required(cmd);
> > }
> >
> > print_hex_dump_debug("(out): ", DUMP_PREFIX_OFFSET, 16, 2, data,
