mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-29 07:04:10 +08:00
b112036535
Phil Oester reported that a fix for a possible buffer overrun that I sent caused a regression that manifests in this output: Event Message: A PCI parity error was detected on a component at bus 0 device 5 function 0. Severity: Critical Message ID: PCI1308 The original code tried to handle the sense data pointer differently when using 32-bit 64-bit DMA addressing, which would lead to a 32-bit dma_addr_t value of 0x11223344 to get stored 32-bit kernel: 44 33 22 11 ?? ?? ?? ?? 64-bit LE kernel: 44 33 22 11 00 00 00 00 64-bit BE kernel: 00 00 00 00 44 33 22 11 or a 64-bit dma_addr_t value of 0x1122334455667788 to get stored as 32-bit kernel: 88 77 66 55 ?? ?? ?? ?? 64-bit kernel: 88 77 66 55 44 33 22 11 In my patch, I tried to ensure that the same value is used on both 32-bit and 64-bit kernels, and picked what seemed to be the most sensible combination, storing 32-bit addresses in the first four bytes (as 32-bit kernels already did), and 64-bit addresses in eight consecutive bytes (as 64-bit kernels already did), but evidently this was incorrect. Always storing the dma_addr_t pointer as 64-bit little-endian, i.e. initializing the second four bytes to zero in case of 32-bit addressing, apparently solved the problem for Phil, and is consistent with what all 64-bit little-endian machines did before. I also checked in the history that in previous versions of the code, the pointer was always in the first four bytes without padding, and that previous attempts to fix 64-bit user space, big-endian architectures and 64-bit DMA were clearly flawed and seem to have introduced made this worse. Link: https://lore.kernel.org/r/20210104234137.438275-1-arnd@kernel.org Fixes: |
||
|---|---|---|
| .. | ||
| Kconfig.megaraid | ||
| Makefile | ||
| mbox_defs.h | ||
| mega_common.h | ||
| megaraid_ioctl.h | ||
| megaraid_mbox.c | ||
| megaraid_mbox.h | ||
| megaraid_mm.c | ||
| megaraid_mm.h | ||
| megaraid_sas_base.c | ||
| megaraid_sas_debugfs.c | ||
| megaraid_sas_fp.c | ||
| megaraid_sas_fusion.c | ||
| megaraid_sas_fusion.h | ||
| megaraid_sas.h | ||