/* * dir.c * * Copyright (c) 1999 Al Smith */ #include #include "efs.h" static int efs_readdir(struct file *, struct dir_context *); const struct file_operations efs_dir_operations = { .llseek = generic_file_llseek, .read = generic_read_dir, .iterate_shared = efs_readdir, }; const struct inode_operations efs_dir_inode_operations = { .lookup = efs_lookup, }; static int efs_readdir(struct file *file, struct dir_context *ctx) { struct inode *inode = file_inode(file); efs_block_t block; int slot; if (inode->i_size & (EFS_DIRBSIZE-1)) pr_warn("%s(): directory size not a multiple of EFS_DIRBSIZE\n", __func__); /* work out where this entry can be found */ block = ctx->pos >> EFS_DIRBSIZE_BITS; /* each block contains at most 256 slots */ slot = ctx->pos & 0xff; /* look at all blocks */ while (block < inode->i_blocks) { struct efs_dir *dirblock; struct buffer_head *bh; /* read the dir block */ bh = sb_bread(inode->i_sb, efs_bmap(inode, block)); if (!bh) { pr_err("%s(): failed to read dir block %d\n", __func__, block); break; } dirblock = (struct efs_dir *) bh->b_data; if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) { pr_err("%s(): invalid directory block\n", __func__); brelse(bh); break; } for (; slot < dirblock->slots; slot++) { struct efs_dentry *dirslot; efs_ino_t inodenum; const char *nameptr; int namelen; if (dirblock->space[slot] == 0) continue; dirslot = (struct efs_dentry *) (((char *) bh->b_data) + EFS_SLOTAT(dirblock, slot)); inodenum = be32_to_cpu(dirslot->inode); namelen = dirslot->namelen; nameptr = dirslot->name; pr_debug("%s(): block %d slot %d/%d: inode %u, name \"%s\", namelen %u\n", __func__, block, slot, dirblock->slots-1, inodenum, nameptr, namelen); if (!namelen) continue; /* found the next entry */ ctx->pos = (block << EFS_DIRBSIZE_BITS) | slot; /* sanity check */ if (nameptr - (char *) dirblock + namelen > EFS_DIRBSIZE) { pr_warn("directory entry %d exceeds directory block\n", slot); continue; } /* copy filename and data in dirslot */ if (!dir_emit(ctx, nameptr, namelen, inodenum, DT_UNKNOWN)) { brelse(bh); return 0; } } brelse(bh); slot = 0; block++; } ctx->pos = (block << EFS_DIRBSIZE_BITS) | slot; return 0; } ethod='get' action='/cgit.cgi/linux/net-next.git/log/drivers/usb/misc/usblcd.c'>
path: root/drivers/usb/misc/usblcd.c
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authorDavid S. Miller <davem@davemloft.net>2017-01-30 14:28:22 -0800
committerDavid S. Miller <davem@davemloft.net>2017-01-30 14:28:22 -0800
commit54791b276b4000b307339f269d3bf7db877d536f (patch)
tree1c2616bd373ce5ea28aac2a53e32f5b5834901ce /drivers/usb/misc/usblcd.c
parent5d0e7705774dd412a465896d08d59a81a345c1e4 (diff)
parent047487241ff59374fded8c477f21453681f5995c (diff)
Merge branch 'sparc64-non-resumable-user-error-recovery'
Liam R. Howlett says: ==================== sparc64: Recover from userspace non-resumable PIO & MEM errors A non-resumable error from userspace is able to cause a kernel panic or trap loop due to the setup and handling of the queued traps once in the kernel. This patch series addresses both of these issues. The queues are fixed by simply zeroing the memory before use. PIO errors from userspace will result in a SIGBUS being sent to the user process. The MEM errors form userspace will result in a SIGKILL and also cause the offending pages to be claimed so they are no longer used in future tasks. SIGKILL is used to ensure that the process does not try to coredump and result in an attempt to read the memory again from within kernel space. Although there is a HV call to scrub the memory (mem_scrub), there is no easy way to guarantee that the real memory address(es) are not used by other tasks. Clearing the error with mem_scrub would zero the memory and cause the other processes to proceed with bad data. The handling of other non-resumable errors remain unchanged and will cause a panic. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/usb/misc/usblcd.c')