From 51ec6bddd3dbebc3a9ff7196efa8c1ac2466696a Mon Sep 17 00:00:00 2001 From: Christian Lamparter Date: Sun, 23 Dec 2018 01:02:33 +0100 Subject: [PATCH] ipq40xx/ipq806x: 4.19: fix qcom-nandc panic on boot This patch fixes the crash that occures on rawnand device. Signed-off-by: Christian Lamparter --- ...-fix-memory-corruption-that-causes-p.patch | 83 +++++++++++++++++++ 1 file changed, 83 insertions(+) create mode 100644 target/linux/generic/hack-4.19/100-mtd-rawnand-qcom-fix-memory-corruption-that-causes-p.patch diff --git a/target/linux/generic/hack-4.19/100-mtd-rawnand-qcom-fix-memory-corruption-that-causes-p.patch b/target/linux/generic/hack-4.19/100-mtd-rawnand-qcom-fix-memory-corruption-that-causes-p.patch new file mode 100644 index 00000000000..9f48ba1cffb --- /dev/null +++ b/target/linux/generic/hack-4.19/100-mtd-rawnand-qcom-fix-memory-corruption-that-causes-p.patch @@ -0,0 +1,83 @@ +From c942c462411e4757aafba73bf13b5e5c7a4b62ca Mon Sep 17 00:00:00 2001 +From: Christian Lamparter +Date: Sun, 23 Dec 2018 00:38:55 +0100 +Subject: [PATCH] mtd: rawnand: qcom: fix memory corruption that causes panic + +This patch fixes a memory corruption that occured in the +qcom-nandc driver since it was converted to nand_scan(). + +On boot, an affected device will panic from a NPE at a weird place: +| Unable to handle kernel NULL pointer dereference at virtual address 00000000 +| pgd = (ptrval) +| [00000000] *pgd=00000000 +| Internal error: Oops: 80000005 [#1] SMP ARM +| CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.9 #0 +| Hardware name: Generic DT based system +| PC is at (null) +| LR is at nand_block_isbad+0x90/0xa4 +| pc : [<00000000>] lr : [] psr: 80000013 +| sp : cf839d40 ip : 00000000 fp : cfae9e20 +| r10: cf815810 r9 : 00000000 r8 : 00000000 +| r7 : 00000000 r6 : 00000000 r5 : 00000001 r4 : cf815810 +| r3 : 00000000 r2 : cfae9810 r1 : ffffffff r0 : cf815810 +| Flags: Nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none +| Control: 10c5387d Table: 8020406a DAC: 00000051 +| Process swapper/0 (pid: 1, stack limit = 0x(ptrval)) +| [] (nand_block_isbad) from [] (allocate_partition+0x7a0/0x7dc) +| [] (allocate_partition) from [] (add_mtd_partitions+0x58/0x10c) +| [] (add_mtd_partitions) from [] (parse_mtd_partitions+0x310/0x338) +| [] (parse_mtd_partitions) from [] (mtd_device_parse_register+0x60/0x15c) +| [] (mtd_device_parse_register) from [] (qcom_nandc_probe+0x770/0x8f4) +| [] (qcom_nandc_probe) from [] (platform_drv_probe+0x34/0x70) + +The problem is that the nand_scan()'s qcom_nand_attach_chip callback +is updating the nandc->max_cwperpage from 1 to 4. This causes the +sg_init_table of clear_bam_transaction() in the driver's +qcom_nandc_block_bad() to memset much more than what was initially +allocated by alloc_bam_transaction(). + +Hence, this patch restores the old behavior by performing the +alloc_bam_transaction() after the chip was identified. + +Fixes: 6a3cec64f18c ("mtd: rawnand: qcom: convert driver to nand_scan()") +Signed-off-by: Christian Lamparter +--- + drivers/mtd/nand/raw/qcom_nandc.c | 20 ++++++++++---------- + 1 file changed, 10 insertions(+), 10 deletions(-) + +--- a/drivers/mtd/nand/raw/qcom_nandc.c ++++ b/drivers/mtd/nand/raw/qcom_nandc.c +@@ -2839,6 +2839,16 @@ static int qcom_nand_host_init_and_regis + if (ret) + return ret; + ++ if (nandc->props->is_bam) { ++ free_bam_transaction(nandc); ++ nandc->bam_txn = alloc_bam_transaction(nandc); ++ if (!nandc->bam_txn) { ++ dev_err(nandc->dev, ++ "failed to allocate bam transaction\n"); ++ return -ENOMEM; ++ } ++ } ++ + ret = mtd_device_register(mtd, NULL, 0); + if (ret) + nand_cleanup(chip); +@@ -2853,16 +2863,6 @@ static int qcom_probe_nand_devices(struc + struct qcom_nand_host *host; + int ret; + +- if (nandc->props->is_bam) { +- free_bam_transaction(nandc); +- nandc->bam_txn = alloc_bam_transaction(nandc); +- if (!nandc->bam_txn) { +- dev_err(nandc->dev, +- "failed to allocate bam transaction\n"); +- return -ENOMEM; +- } +- } +- + for_each_available_child_of_node(dn, child) { + host = devm_kzalloc(dev, sizeof(*host), GFP_KERNEL); + if (!host) {