Commit e5ce067b authored by Matthew R. Ochs's avatar Matthew R. Ochs Committed by James Bottomley

cxlflash: Fix AFU version access/storage and add check

The AFU version is stored as a non-terminated string of bytes within
a 64-bit little-endian register. Presently the value is read directly
(no MMIO accessor) and is stored in a buffer that is not big enough
to contain a NULL terminator. Additionally the version obtained is not
evaluated against a known value to prevent usage with unsupported AFUs.
All of these deficiencies can lead to a variety of problems.

To remedy, use the correct MMIO accessor to read the version value into
a null-terminated buffer and add a check to prevent an incompatible AFU
from being used with this driver.
Signed-off-by: default avatarMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: default avatarManoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: default avatarBrian King <brking@linux.vnet.ibm.com>
Reviewed-by: default avatarDaniel Axtens <dja@axtens.net>
Reviewed-by: default avatarTomas Henzl <thenzl@redhat.com>
Signed-off-by: default avatarJames Bottomley <JBottomley@Odin.com>
parent 964497b3
......@@ -179,7 +179,7 @@ struct afu {
u32 cmd_couts; /* Number of command checkouts */
u32 internal_lun; /* User-desired LUN mode for this AFU */
char version[8];
char version[16];
u64 interface_version;
struct cxlflash_cfg *parent; /* Pointer back to parent cxlflash_cfg */
......
......@@ -1751,12 +1751,18 @@ static int init_afu(struct cxlflash_cfg *cfg)
goto err1;
}
/* don't byte reverse on reading afu_version, else the string form */
/* will be backwards */
reg = afu->afu_map->global.regs.afu_version;
memcpy(afu->version, &reg, 8);
/* No byte reverse on reading afu_version or string will be backwards */
reg = readq(&afu->afu_map->global.regs.afu_version);
memcpy(afu->version, &reg, sizeof(reg));
afu->interface_version =
readq_be(&afu->afu_map->global.regs.interface_version);
if ((afu->interface_version + 1) == 0) {
pr_err("Back level AFU, please upgrade. AFU version %s "
"interface version 0x%llx\n", afu->version,
afu->interface_version);
rc = -EINVAL;
goto err1;
} else
pr_debug("%s: afu version %s, interface version 0x%llX\n",
__func__, afu->version, afu->interface_version);
......
......@@ -340,7 +340,7 @@ struct sisl_global_regs {
#define SISL_AFUCONF_MBOX_CLR_READ 0x0010ULL
__be64 afu_config;
__be64 rsvd[0xf8];
__be64 afu_version;
__le64 afu_version;
__be64 interface_version;
};
......
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