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powerpc/pseries: Fix handling of PLPKS object flushing timeout

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plpks_confirm_object_flushed() uses the H_PKS_CONFIRM_OBJECT_FLUSHED hcall
to check whether changes to an object in the Platform KeyStore have been
flushed to non-volatile storage.

The hcall returns two output values, the return code and the flush status.
plpks_confirm_object_flushed() polls the hcall until either the flush
status has updated, the return code is an error, or a timeout has been
exceeded.

While we're still polling, the hcall is returning H_SUCCESS (0) as the
return code. In the timeout case, this means that upon exiting the polling
loop, rc is 0, and therefore 0 is returned to the user.

Handle the timeout case separately and return ETIMEDOUT if triggered.

Fixes: 2454a7af0f2a ("powerpc/pseries: define driver for Platform KeyStore")
Reported-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Tested-by: Russell Currey <ruscur@russell.cc>
Reviewed-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230210080401.345462-2-ajd@linux.ibm.com
This commit is contained in:
Andrew Donnellan 2023-02-10 19:03:36 +11:00 committed by Michael Ellerman
parent fc8a898cfd
commit f74dcbfd27
1 changed files with 8 additions and 3 deletions
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11
arch/powerpc/platforms/pseries/plpks.c
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@ -248,6 +248,7 @@ static int plpks_confirm_object_flushed(struct label *label,
struct plpks_auth *auth)
{
unsigned long retbuf[PLPAR_HCALL_BUFSIZE] = { 0 };
bool timed_out = true;
u64 timeout = 0;
u8 status;
int rc;
@ -259,22 +260,26 @@ static int plpks_confirm_object_flushed(struct label *label,
status = retbuf[0];
if (rc) {
timed_out = false;
if (rc == H_NOT_FOUND && status == 1)
rc = 0;
break;
}
if (!rc && status == 1)
if (!rc && status == 1) {
timed_out = false;
break;
}
usleep_range(PKS_FLUSH_SLEEP,
PKS_FLUSH_SLEEP + PKS_FLUSH_SLEEP_RANGE);
timeout = timeout + PKS_FLUSH_SLEEP;
} while (timeout < PKS_FLUSH_MAX_TIMEOUT);
rc = pseries_status_to_err(rc);
if (timed_out)
return -ETIMEDOUT;
return rc;
return pseries_status_to_err(rc);
}
int plpks_write_var(struct plpks_var var)