From: Harald Freudenberger freude@linux.ibm.com
[ Upstream commit d39fae45c97c67b1b4da04773f2bb5a2f29088c4 ]
When a msg is retried because the lower ap layer returns -EAGAIN there is a retry limit (currently 10). When this limit is reached the last return code from the lower layer is returned, causing the userspace to get -1 on the ioctl with errno EAGAIN.
This EAGAIN is misleading here. After 10 retry attempts the userspace should receive a clear failure indication like EINVAL or EIO or ENODEV. However, the reason why these retries all fail is unclear. On an invalid message EINVAL would be returned by the lower layer, and if devices go away or are not available an ENODEV is seen. So this patch now reworks the retry loops to return EIO to userspace when the retry limit is reached.
Fixes: 91ffc519c199 ("s390/zcrypt: introduce msg tracking in zcrypt functions") Signed-off-by: Harald Freudenberger freude@linux.ibm.com Signed-off-by: Vasily Gorbik gor@linux.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/s390/crypto/zcrypt_api.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c index 10206e4498d07..52eaf51c9bb64 100644 --- a/drivers/s390/crypto/zcrypt_api.c +++ b/drivers/s390/crypto/zcrypt_api.c @@ -1438,6 +1438,8 @@ static int icarsamodexpo_ioctl(struct ap_perms *perms, unsigned long arg) if (rc == -EAGAIN) tr.again_counter++; } while (rc == -EAGAIN && tr.again_counter < TRACK_AGAIN_MAX); + if (rc == -EAGAIN && tr.again_counter >= TRACK_AGAIN_MAX) + rc = -EIO; if (rc) { ZCRYPT_DBF(DBF_DEBUG, "ioctl ICARSAMODEXPO rc=%d\n", rc); return rc; @@ -1481,6 +1483,8 @@ static int icarsacrt_ioctl(struct ap_perms *perms, unsigned long arg) if (rc == -EAGAIN) tr.again_counter++; } while (rc == -EAGAIN && tr.again_counter < TRACK_AGAIN_MAX); + if (rc == -EAGAIN && tr.again_counter >= TRACK_AGAIN_MAX) + rc = -EIO; if (rc) { ZCRYPT_DBF(DBF_DEBUG, "ioctl ICARSACRT rc=%d\n", rc); return rc; @@ -1524,6 +1528,8 @@ static int zsecsendcprb_ioctl(struct ap_perms *perms, unsigned long arg) if (rc == -EAGAIN) tr.again_counter++; } while (rc == -EAGAIN && tr.again_counter < TRACK_AGAIN_MAX); + if (rc == -EAGAIN && tr.again_counter >= TRACK_AGAIN_MAX) + rc = -EIO; if (rc) ZCRYPT_DBF(DBF_DEBUG, "ioctl ZSENDCPRB rc=%d status=0x%x\n", rc, xcRB.status); @@ -1568,6 +1574,8 @@ static int zsendep11cprb_ioctl(struct ap_perms *perms, unsigned long arg) if (rc == -EAGAIN) tr.again_counter++; } while (rc == -EAGAIN && tr.again_counter < TRACK_AGAIN_MAX); + if (rc == -EAGAIN && tr.again_counter >= TRACK_AGAIN_MAX) + rc = -EIO; if (rc) ZCRYPT_DBF(DBF_DEBUG, "ioctl ZSENDEP11CPRB rc=%d\n", rc); if (copy_to_user(uxcrb, &xcrb, sizeof(xcrb))) @@ -1744,6 +1752,8 @@ static long trans_modexpo32(struct ap_perms *perms, struct file *filp, if (rc == -EAGAIN) tr.again_counter++; } while (rc == -EAGAIN && tr.again_counter < TRACK_AGAIN_MAX); + if (rc == -EAGAIN && tr.again_counter >= TRACK_AGAIN_MAX) + rc = -EIO; if (rc) return rc; return put_user(mex64.outputdatalength, @@ -1795,6 +1805,8 @@ static long trans_modexpo_crt32(struct ap_perms *perms, struct file *filp, if (rc == -EAGAIN) tr.again_counter++; } while (rc == -EAGAIN && tr.again_counter < TRACK_AGAIN_MAX); + if (rc == -EAGAIN && tr.again_counter >= TRACK_AGAIN_MAX) + rc = -EIO; if (rc) return rc; return put_user(crt64.outputdatalength, @@ -1865,6 +1877,8 @@ static long trans_xcRB32(struct ap_perms *perms, struct file *filp, if (rc == -EAGAIN) tr.again_counter++; } while (rc == -EAGAIN && tr.again_counter < TRACK_AGAIN_MAX); + if (rc == -EAGAIN && tr.again_counter >= TRACK_AGAIN_MAX) + rc = -EIO; xcRB32.reply_control_blk_length = xcRB64.reply_control_blk_length; xcRB32.reply_data_length = xcRB64.reply_data_length; xcRB32.status = xcRB64.status;