This patch fixes a memory corruption that occurred in the
nand_scan() path for Hynix nand device.
On boot, for Hynix nand device will panic at a weird place:
| Unable to handle kernel NULL pointer dereference at virtual
address 00000070
| [00000070] *pgd=00000000
| Internal error: Oops: 5 [#1] PREEMPT SMP ARM
| Modules linked in:
| CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.17.0-01473-g13ae1769cfb0
#38
| Hardware name: Generic DT based system
| PC is at nandc_set_reg+0x8/0x1c
| LR is at qcom_nandc_command+0x20c/0x5d0
| pc : [<c088b74c>] lr : [<c088d9c8>] psr: 00000113
| sp : c14adc50 ip : c14ee208 fp : c0cc970c
| r10: 000000a3 r9 : 00000000 r8 : 00000040
| r7 : c16f6a00 r6 : 00000090 r5 : 00000004 r4 :c14ee040
| r3 : 00000000 r2 : 0000000b r1 : 00000000 r0 :c14ee040
| Flags: nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none
| Control: 10c5387d Table: 8020406a DAC: 00000051
| Register r0 information: slab kmalloc-2k start c14ee000 pointer offset
64 size 2048
| Process swapper/0 (pid: 1, stack limit = 0x(ptrval))
| nandc_set_reg from qcom_nandc_command+0x20c/0x5d0
| qcom_nandc_command from nand_readid_op+0x198/0x1e8
| nand_readid_op from hynix_nand_has_valid_jedecid+0x30/0x78
| hynix_nand_has_valid_jedecid from hynix_nand_init+0xb8/0x454
| hynix_nand_init from nand_scan_with_ids+0xa30/0x14a8
| nand_scan_with_ids from qcom_nandc_probe+0x648/0x7b0
| qcom_nandc_probe from platform_probe+0x58/0xac
The problem is that the nand_scan()'s qcom_nand_attach_chip callback
is updating the nandc->max_cwperpage from 1 to 4 or 8 based on page size.
This causes the sg_init_table of clear_bam_transaction() in the driver's
qcom_nandc_command() to memset much more than what was initially
allocated by alloc_bam_transaction().
This patch will update nandc->max_cwperpage 1 to 4 or 8 based on page
size in qcom_nand_attach_chip call back after freeing the previously
allocated memory for bam txn as per nandc->max_cwperpage = 1 and then
again allocating bam txn as per nandc->max_cwperpage = 4 or 8 based on
page size in qcom_nand_attach_chip call back itself.
Cc: stable@vger.kernel.org
Fixes: 6a3cec64f1 ("mtd: rawnand: qcom: convert driver to nand_scan()")
Reported-by: Konrad Dybcio <konrad.dybcio@somainline.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Co-developed-by: Sricharan R <quic_srichara@quicinc.com>
Signed-off-by: Sricharan R <quic_srichara@quicinc.com>
Signed-off-by: Md Sadre Alam <quic_mdalam@quicinc.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/1650268107-5363-1-git-send-email-quic_mdalam@quicinc.com
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