6.6-stable review patch. If anyone has any objections, please let me know.
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From: Qiuxu Zhuo qiuxu.zhuo@intel.com
[ Upstream commit 2e6fe1bbefd9c059c3787d1c620fe67343a94dff ]
When loading the i10nm_edac driver on some Intel Granite Rapids servers, a call trace may appear as follows:
UBSAN: shift-out-of-bounds in drivers/edac/skx_common.c:453:16 shift exponent -66 is negative ... __ubsan_handle_shift_out_of_bounds+0x1e3/0x390 skx_get_dimm_info.cold+0x47/0xd40 [skx_edac_common] i10nm_get_dimm_config+0x23e/0x390 [i10nm_edac] skx_register_mci+0x159/0x220 [skx_edac_common] i10nm_init+0xcb0/0x1ff0 [i10nm_edac] ...
This occurs because some BIOS may disable a memory controller if there aren't any memory DIMMs populated on this memory controller. The DIMMMTR register of this disabled memory controller contains the invalid value ~0, resulting in the call trace above.
Fix this call trace by skipping DIMM enumeration on a disabled memory controller.
Fixes: ba987eaaabf9 ("EDAC/i10nm: Add Intel Granite Rapids server support") Reported-by: Jose Jesus Ambriz Meza jose.jesus.ambriz.meza@intel.com Reported-by: Chia-Lin Kao (AceLan) acelan.kao@canonical.com Closes: https://lore.kernel.org/all/20250730063155.2612379-1-acelan.kao@canonical.co... Signed-off-by: Qiuxu Zhuo qiuxu.zhuo@intel.com Signed-off-by: Tony Luck tony.luck@intel.com Tested-by: Chia-Lin Kao (AceLan) acelan.kao@canonical.com Link: https://lore.kernel.org/r/20250806065707.3533345-1-qiuxu.zhuo@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/edac/i10nm_base.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
diff --git a/drivers/edac/i10nm_base.c b/drivers/edac/i10nm_base.c index 068597e8fce95..3c70d86074975 100644 --- a/drivers/edac/i10nm_base.c +++ b/drivers/edac/i10nm_base.c @@ -970,6 +970,15 @@ static bool i10nm_check_ecc(struct skx_imc *imc, int chan) return !!GET_BITFIELD(mcmtr, 2, 2); }
+static bool i10nm_channel_disabled(struct skx_imc *imc, int chan) +{ + u32 mcmtr = I10NM_GET_MCMTR(imc, chan); + + edac_dbg(1, "mc%d ch%d mcmtr reg %x\n", imc->mc, chan, mcmtr); + + return (mcmtr == ~0 || GET_BITFIELD(mcmtr, 18, 18)); +} + static int i10nm_get_dimm_config(struct mem_ctl_info *mci, struct res_config *cfg) { @@ -983,6 +992,11 @@ static int i10nm_get_dimm_config(struct mem_ctl_info *mci, if (!imc->mbase) continue;
+ if (i10nm_channel_disabled(imc, i)) { + edac_dbg(1, "mc%d ch%d is disabled.\n", imc->mc, i); + continue; + } + ndimms = 0; amap = I10NM_GET_AMAP(imc, i);