#ifndef __PERF_STRBUF_H #define __PERF_STRBUF_H /* * Strbuf's can be use in many ways: as a byte array, or to store arbitrary * long, overflow safe strings. * * Strbufs has some invariants that are very important to keep in mind: * * 1. the ->buf member is always malloc-ed, hence strbuf's can be used to * build complex strings/buffers whose final size isn't easily known. * * It is NOT legal to copy the ->buf pointer away. * `strbuf_detach' is the operation that detachs a buffer from its shell * while keeping the shell valid wrt its invariants. * * 2. the ->buf member is a byte array that has at least ->len + 1 bytes * allocated. The extra byte is used to store a '\0', allowing the ->buf * member to be a valid C-string. Every strbuf function ensure this * invariant is preserved. * * Note that it is OK to "play" with the buffer directly if you work it * that way: * * strbuf_grow(sb, SOME_SIZE); * ... Here, the memory array starting at sb->buf, and of length * ... strbuf_avail(sb) is all yours, and you are sure that * ... strbuf_avail(sb) is at least SOME_SIZE. * strbuf_setlen(sb, sb->len + SOME_OTHER_SIZE); * * Of course, SOME_OTHER_SIZE must be smaller or equal to strbuf_avail(sb). * * Doing so is safe, though if it has to be done in many places, adding the * missing API to the strbuf module is the way to go. * * XXX: do _not_ assume that the area that is yours is of size ->alloc - 1 * even if it's true in the current implementation. Alloc is somehow a * "private" member that should not be messed with. */ #include #include #include #include #include extern char strbuf_slopbuf[]; struct strbuf { size_t alloc; size_t len; char *buf; }; #define STRBUF_INIT { 0, 0, strbuf_slopbuf } /*----- strbuf life cycle -----*/ int strbuf_init(struct strbuf *buf, ssize_t hint); void strbuf_release(struct strbuf *buf); char *strbuf_detach(struct strbuf *buf, size_t *); /*----- strbuf size related -----*/ static inline ssize_t strbuf_avail(const struct strbuf *sb) { return sb->alloc ? sb->alloc - sb->len - 1 : 0; } int strbuf_grow(struct strbuf *buf, size_t); static inline int strbuf_setlen(struct strbuf *sb, size_t len) { if (!sb->alloc) { int ret = strbuf_grow(sb, 0); if (ret) return ret; } assert(len < sb->alloc); sb->len = len; sb->buf[len] = '\0'; return 0; } /*----- add data in your buffer -----*/ int strbuf_addch(struct strbuf *sb, int c); int strbuf_add(struct strbuf *buf, const void *, size_t); static inline int strbuf_addstr(struct strbuf *sb, const char *s) { return strbuf_add(sb, s, strlen(s)); } __attribute__((format(printf,2,3))) int strbuf_addf(struct strbuf *sb, const char *fmt, ...); /* XXX: if read fails, any partial read is undone */ ssize_t strbuf_read(struct strbuf *, int fd, ssize_t hint); #endif /* __PERF_STRBUF_H */ linux/net-next.git/commit/fs/affs/amigaffs.c?id=3277953de2f31dd03c6375e9a9f680ac37fc9d27'>amigaffs.c
diff options
context:
space:
mode:
authorzhong jiang <zhongjiang@huawei.com>2017-01-24 15:18:52 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-01-24 16:26:14 -0800
commit3277953de2f31dd03c6375e9a9f680ac37fc9d27 (patch)
tree6ba22924faa1b82ef2f0277db10a3f5abdc44157 /fs/affs/amigaffs.c
parent3705ccfdd1e8b539225ce20e3925a945cc788d67 (diff)
mm: do not export ioremap_page_range symbol for external module
Recently, I've found cases in which ioremap_page_range was used incorrectly, in external modules, leading to crashes. This can be partly attributed to the fact that ioremap_page_range is lower-level, with fewer protections, as compared to the other functions that an external module would typically call. Those include: ioremap_cache ioremap_nocache ioremap_prot ioremap_uc ioremap_wc ioremap_wt ...each of which wraps __ioremap_caller, which in turn provides a safer way to achieve the mapping. Therefore, stop EXPORT-ing ioremap_page_range. Link: http://lkml.kernel.org/r/1485173220-29010-1-git-send-email-zhongjiang@huawei.com Signed-off-by: zhong jiang <zhongjiang@huawei.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Suggested-by: John Hubbard <jhubbard@nvidia.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/affs/amigaffs.c')