kernel/linux.git/drivers/misc/eeprom/at25.c, branch v6.2

eeprom: at25: Rework buggy read splitting

2022-06-27T14:21:05+00:00

The recent change to split reads into chunks has several problems: 1. If an SPI controller has no transfer size limit, max_chunk is SIZE_MAX, and num_msgs becomes zero, causing no data to be read into the buffer, and exposing the original contents of the buffer to userspace, 2. If the requested read size is not a multiple of the maximum transfer size, the last transfer reads too much data, overflowing the buffer, 3. The loop logic differs from the write case. Fix the above by: 1. Keeping track of the number of bytes that are still to be transferred, instead of precalculating the number of messages and keeping track of the number of bytes tranfered, 2. Calculating the transfer size of each individual message, taking into account the number of bytes left, 3. Switching from a "while"-loop to a "do-while"-loop, and renaming "msg_count" to "segment". While at it, drop the superfluous cast from "unsigned int" to "unsigned int", also from at25_ee_write(), where it was probably copied from. Fixes: 0a35780c755ccec0 ("eeprom: at25: Split reads into chunks and cap write size") Signed-off-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/7ae260778d2c08986348ea48ce02ef148100e088.1655817534.git.geert+renesas@glider.be Signed-off-by: Greg Kroah-Hartman

eeprom: at25: Split reads into chunks and cap write size

2022-06-10T14:42:48+00:00

Make use of spi_max_transfer_size to avoid requesting transfers that are too large for some spi controllers. Signed-off-by: Brad Bishop Signed-off-by: Eddie James Signed-off-by: Joel Stanley Link: https://lore.kernel.org/r/20220524215142.60047-1-eajames@linux.ibm.com Signed-off-by: Greg Kroah-Hartman

eeprom: at25: Use DMA safe buffers

2022-04-24T15:25:10+00:00

Reading EEPROM fails with following warning: [ 16.357496] ------------[ cut here ]------------ [ 16.357529] fsl_spi b01004c0.spi: rejecting DMA map of vmalloc memory [ 16.357698] WARNING: CPU: 0 PID: 371 at include/linux/dma-mapping.h:326 fsl_spi_cpm_bufs+0x2a0/0x2d8 [ 16.357775] CPU: 0 PID: 371 Comm: od Not tainted 5.16.11-s3k-dev-01743-g19beecbfe9d6-dirty #109 [ 16.357806] NIP: c03fbc9c LR: c03fbc9c CTR: 00000000 [ 16.357825] REGS: e68d9b20 TRAP: 0700 Not tainted (5.16.11-s3k-dev-01743-g19beecbfe9d6-dirty) [ 16.357849] MSR: 00029032 CR: 24002282 XER: 00000000 [ 16.357931] [ 16.357931] GPR00: c03fbc9c e68d9be0 c26d06a0 00000039 00000001 c0d36364 c0e96428 00000027 [ 16.357931] GPR08: 00000001 00000000 00000023 3fffc000 24002282 100d3dd6 100a2ffc 00000000 [ 16.357931] GPR16: 100cd280 100b0000 00000000 aff54f7e 100d0000 100d0000 00000001 100cf328 [ 16.357931] GPR24: 100cf328 00000000 00000003 e68d9e30 c156b410 e67ab4c0 e68d9d38 c24ab278 [ 16.358253] NIP [c03fbc9c] fsl_spi_cpm_bufs+0x2a0/0x2d8 [ 16.358292] LR [c03fbc9c] fsl_spi_cpm_bufs+0x2a0/0x2d8 [ 16.358325] Call Trace: [ 16.358336] [e68d9be0] [c03fbc9c] fsl_spi_cpm_bufs+0x2a0/0x2d8 (unreliable) [ 16.358388] [e68d9c00] [c03fcb44] fsl_spi_bufs.isra.0+0x94/0x1a0 [ 16.358436] [e68d9c20] [c03fd970] fsl_spi_do_one_msg+0x254/0x3dc [ 16.358483] [e68d9cb0] [c03f7e50] __spi_pump_messages+0x274/0x8a4 [ 16.358529] [e68d9ce0] [c03f9d30] __spi_sync+0x344/0x378 [ 16.358573] [e68d9d20] [c03fb52c] spi_sync+0x34/0x60 [ 16.358616] [e68d9d30] [c03b4dec] at25_ee_read+0x138/0x1a8 [ 16.358667] [e68d9e50] [c04a8fb8] bin_attr_nvmem_read+0x98/0x110 [ 16.358725] [e68d9e60] [c0204b14] kernfs_fop_read_iter+0xc0/0x1fc [ 16.358774] [e68d9e80] [c0168660] vfs_read+0x284/0x410 [ 16.358821] [e68d9f00] [c016925c] ksys_read+0x6c/0x11c [ 16.358863] [e68d9f30] [c00160e0] ret_from_syscall+0x0/0x28 ... [ 16.359608] ---[ end trace a4ce3e34afef0cb5 ]--- [ 16.359638] fsl_spi b01004c0.spi: unable to map tx dma This is due to the AT25 driver using buffers on stack, which is not possible with CONFIG_VMAP_STACK. As mentionned in kernel Documentation (Documentation/spi/spi-summary.rst): - Follow standard kernel rules, and provide DMA-safe buffers in your messages. That way controller drivers using DMA aren't forced to make extra copies unless the hardware requires it (e.g. working around hardware errata that force the use of bounce buffering). Modify the driver to use a buffer located in the at25 device structure which is allocated via kmalloc during probe. Protect writes in this new buffer with the driver's mutex. Fixes: b587b13a4f67 ("[PATCH] SPI eeprom driver") Cc: stable Signed-off-by: Christophe Leroy Link: https://lore.kernel.org/r/230a9486fc68ea0182df46255e42a51099403642.1648032613.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman

Merge tag 'v5.17-rc2' into char-misc-next

2022-01-30T14:00:39+00:00

We need the char/misc fixes in here as well. Signed-off-by: Greg Kroah-Hartman

eeprom: at25: Replace strncpy() with strscpy()

2022-01-26T18:37:06+00:00

Use strscpy() instead of strncpy(), since its use has been deprecated[1]. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings Cc: Greg Kroah-Hartman Cc: Andy Shevchenko Cc: Arnd Bergmann Cc: Jiri Prchal Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20220118182047.3385295-1-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman

eeprom: at25: Restore missing allocation

2022-01-22T12:32:48+00:00

The at25 driver regressed in v5.17-rc1 due to a broken conflict resolution: the allocation of the object was accidentally removed. Restore it. This was found when building under CONFIG_FORTIFY_SOURCE=y and -Warray-bounds, which complained about strncpy() being used against an empty object: In function 'strncpy', inlined from 'at25_fw_to_chip.constprop' at drivers/misc/eeprom/at25.c:312:2: ./include/linux/fortify-string.h:48:33: warning: '__builtin_strncpy' offset [0, 9] is out of the bounds [0, 0] [-Warray-bounds] 48 | #define __underlying_strncpy __builtin_strncpy | ^ ./include/linux/fortify-string.h:59:16: note: in expansion of macro '__underlying_strncpy' 59 | return __underlying_strncpy(p, q, size); | ^~~~~~~~~~~~~~~~~~~~ In function 'strncpy', inlined from 'at25_fram_to_chip' at drivers/misc/eeprom/at25.c:373:2, inlined from 'at25_probe' at drivers/misc/eeprom/at25.c:453:10: ./include/linux/fortify-string.h:48:33: warning: '__builtin_strncpy' offset [0, 9] is out of the bounds [0, 0] [-Warray-bounds] 48 | #define __underlying_strncpy __builtin_strncpy | ^ ./include/linux/fortify-string.h:59:16: note: in expansion of macro '__underlying_strncpy' 59 | return __underlying_strncpy(p, q, size); | ^~~~~~~~~~~~~~~~~~~~ Link: https://lore.kernel.org/lkml/CAHp75VdqK7h63fz-cPaQ2MGaVdaR2f1Fb5kKCZidUG3RwLsAVA@mail.gmail.com/ Fixes: af40d16042d6 ("Merge v5.15-rc5 into char-misc-next") Cc: Arnd Bergmann Cc: Jiri Prchal Reviewed-by: Andy Shevchenko Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20220118182003.3385019-1-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman

Merge v5.15-rc5 into char-misc-next

2021-12-13T09:17:10+00:00

We need the fixes in here as well, and also resolve some merge conflicts in: drivers/misc/eeprom/at25.c Signed-off-by: Greg Kroah-Hartman

misc: at25: Align comment style

2021-12-03T13:26:15+00:00

Make multi-line comment style aligned. While at it, drop filename from the file. Acked-by: Arnd Bergmann Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20211125213203.86693-11-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman

misc: at25: Replace commas by spaces in the ID tables

2021-12-03T13:26:15+00:00

For better readability replace commas by spaces in the ID tables. Acked-by: Arnd Bergmann Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20211125213203.86693-10-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman

misc: at25: Reorganize headers for better maintenance

2021-12-03T13:26:15+00:00

Split headers to three groups and sort alphabetically in each of them. Acked-by: Arnd Bergmann Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20211125213203.86693-9-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman