diff options
| author | Elyes HAOUAS <ehaouas@noos.fr> | 2019-09-24 14:24:45 +0200 |
|---|---|---|
| committer | Nico Huber <nico.h@gmx.de> | 2019-10-08 11:03:26 +0000 |
| commit | 2a0fbe34ba037a5064b3becea2b6c6e1005926ff (patch) | |
| tree | e86a5f3e463f91a83162e510e18f27f8a860bc9f /src/device/dram | |
| parent | c1dc2d5e687cd8ba8164d593b875977f2f6dcbd4 (diff) | |
device/dram/ddr4: Check spd_bytes_total and spd_bytes_used values
The value stored to 'spd_bytes_total' is never read. Now it is fixed.
This is spotted using clang-tool v9.
Also add a check if spd_bytes_used and/or spd_bytes_total are reserved
and make sure that spd_bytes_used is not greater than spd_bytes_total.
Change-Id: I426a7e64cc4c0bcced91d03387e02c8d965a21dc
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/35558
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Diffstat (limited to 'src/device/dram')
| -rw-r--r-- | src/device/dram/ddr4.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/src/device/dram/ddr4.c b/src/device/dram/ddr4.c index 4f99ecc925..07f9decb74 100644 --- a/src/device/dram/ddr4.c +++ b/src/device/dram/ddr4.c @@ -111,17 +111,31 @@ int spd_decode_ddr4(dimm_attr *dimm, spd_raw_data spd) return SPD_STATUS_INVALID; } - spd_bytes_total = (spd[0] >> 4) & ((1 << 3) - 1); - spd_bytes_used = spd[0] & ((1 << 4) - 1); + spd_bytes_total = (spd[0] >> 4) & 0x7; + spd_bytes_used = spd[0] & 0xf; if (!spd_bytes_total || !spd_bytes_used) { printk(BIOS_ERR, "SPD failed basic sanity checks\n"); return SPD_STATUS_INVALID; } + if (spd_bytes_total >= 3) + printk(BIOS_WARNING, "SPD Bytes Total value is reserved\n"); + spd_bytes_total = 256 << (spd_bytes_total - 1); + + if (spd_bytes_used > 4) { + printk(BIOS_ERR, "SPD Bytes Used value is reserved\n"); + return SPD_STATUS_INVALID; + } + spd_bytes_used = spd_bytes_used_table[spd_bytes_used]; + if (spd_bytes_used > spd_bytes_total) { + printk(BIOS_ERR, "SPD Bytes Used is greater than SPD Bytes Total\n"); + return SPD_STATUS_INVALID; + } + /* Verify CRC of blocks that have them, do not step over 'used' length */ for (int i = 0; i < ARRAY_SIZE(spd_blocks); i++) { /* this block is not checksumed */ |