Cur_len can't be less than 0 because it has type size_t, which is unsigned. julia ---------- Forwarded message ---------- Date: Thu, 1 Nov 2018 11:37:21 +0800 From: kbuild test robot <lkp@xxxxxxxxx> To: kbuild@xxxxxx Cc: Julia Lawall <julia.lawall@xxxxxxx> Subject: [cifs:for-next 7/9] fs/cifs/file.c:3203:7-14: WARNING: Unsigned expression compared with zero: cur_len < 0 CC: kbuild-all@xxxxxx CC: linux-cifs@xxxxxxxxxxxxxxx CC: samba-technical@xxxxxxxxxxxxxxx TO: Long Li <longli@xxxxxxxxxxxxx> CC: Steve French <stfrench@xxxxxxxxxxxxx> tree: git://git.samba.org/sfrench/cifs-2.6.git for-next head: 7d8ceb129086fc6c0537fa37d6a4b65f490da006 commit: 27d00133fadd8753e1856889dea2da4cb22910a3 [7/9] CIFS: Add support for direct I/O read :::::: branch date: :::::: commit date: 3 hours ago >> fs/cifs/file.c:3203:7-14: WARNING: Unsigned expression compared with zero: cur_len < 0 git remote add cifs git://git.samba.org/sfrench/cifs-2.6.git git remote update cifs git checkout 27d00133fadd8753e1856889dea2da4cb22910a3 vim +3203 fs/cifs/file.c 27d00133 Long Li 2018-10-31 3164 d70b9104 Pavel Shilovsky 2016-11-17 3165 static int 0ada36b2 Pavel Shilovsky 2014-06-25 3166 cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file, 6685c5e2 Pavel Shilovsky 2017-04-25 3167 struct cifs_sb_info *cifs_sb, struct list_head *rdata_list, 6685c5e2 Pavel Shilovsky 2017-04-25 3168 struct cifs_aio_ctx *ctx) ^1da177e Linus Torvalds 2005-04-16 3169 { 0ada36b2 Pavel Shilovsky 2014-06-25 3170 struct cifs_readdata *rdata; bed9da02 Pavel Shilovsky 2014-06-25 3171 unsigned int npages, rsize, credits; 0ada36b2 Pavel Shilovsky 2014-06-25 3172 size_t cur_len; 0ada36b2 Pavel Shilovsky 2014-06-25 3173 int rc; 1c892549 Jeff Layton 2012-05-16 3174 pid_t pid; 25f40259 Pavel Shilovsky 2014-06-25 3175 struct TCP_Server_Info *server; 27d00133 Long Li 2018-10-31 3176 struct page **pagevec; 27d00133 Long Li 2018-10-31 3177 size_t start; 27d00133 Long Li 2018-10-31 3178 struct iov_iter direct_iov = ctx->iter; a70307ee Pavel Shilovsky 2010-12-14 3179 25f40259 Pavel Shilovsky 2014-06-25 3180 server = tlink_tcon(open_file->tlink)->ses->server; fc9c5966 Pavel Shilovsky 2012-09-18 3181 d4ffff1f Pavel Shilovsky 2011-05-26 3182 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD) d4ffff1f Pavel Shilovsky 2011-05-26 3183 pid = open_file->pid; d4ffff1f Pavel Shilovsky 2011-05-26 3184 else d4ffff1f Pavel Shilovsky 2011-05-26 3185 pid = current->tgid; d4ffff1f Pavel Shilovsky 2011-05-26 3186 27d00133 Long Li 2018-10-31 3187 if (ctx->direct_io) 27d00133 Long Li 2018-10-31 3188 iov_iter_advance(&direct_iov, offset - ctx->pos); 27d00133 Long Li 2018-10-31 3189 1c892549 Jeff Layton 2012-05-16 3190 do { bed9da02 Pavel Shilovsky 2014-06-25 3191 rc = server->ops->wait_mtu_credits(server, cifs_sb->rsize, bed9da02 Pavel Shilovsky 2014-06-25 3192 &rsize, &credits); bed9da02 Pavel Shilovsky 2014-06-25 3193 if (rc) bed9da02 Pavel Shilovsky 2014-06-25 3194 break; bed9da02 Pavel Shilovsky 2014-06-25 3195 bed9da02 Pavel Shilovsky 2014-06-25 3196 cur_len = min_t(const size_t, len, rsize); a70307ee Pavel Shilovsky 2010-12-14 3197 27d00133 Long Li 2018-10-31 3198 if (ctx->direct_io) { 27d00133 Long Li 2018-10-31 3199 27d00133 Long Li 2018-10-31 3200 cur_len = iov_iter_get_pages_alloc( 27d00133 Long Li 2018-10-31 3201 &direct_iov, &pagevec, 27d00133 Long Li 2018-10-31 3202 cur_len, &start); 27d00133 Long Li 2018-10-31 @3203 if (cur_len < 0) { 27d00133 Long Li 2018-10-31 3204 cifs_dbg(VFS, 27d00133 Long Li 2018-10-31 3205 "couldn't get user pages (cur_len=%zd)" 27d00133 Long Li 2018-10-31 3206 " iter type %d" 27d00133 Long Li 2018-10-31 3207 " iov_offset %zd count %zd\n", 27d00133 Long Li 2018-10-31 3208 cur_len, direct_iov.type, direct_iov.iov_offset, 27d00133 Long Li 2018-10-31 3209 direct_iov.count); 27d00133 Long Li 2018-10-31 3210 dump_stack(); 27d00133 Long Li 2018-10-31 3211 break; 27d00133 Long Li 2018-10-31 3212 } 27d00133 Long Li 2018-10-31 3213 iov_iter_advance(&direct_iov, cur_len); 27d00133 Long Li 2018-10-31 3214 27d00133 Long Li 2018-10-31 3215 rdata = cifs_readdata_direct_alloc( 27d00133 Long Li 2018-10-31 3216 pagevec, cifs_uncached_readv_complete); 27d00133 Long Li 2018-10-31 3217 if (!rdata) { 27d00133 Long Li 2018-10-31 3218 add_credits_and_wake_if(server, credits, 0); 27d00133 Long Li 2018-10-31 3219 rc = -ENOMEM; 27d00133 Long Li 2018-10-31 3220 break; 27d00133 Long Li 2018-10-31 3221 } 27d00133 Long Li 2018-10-31 3222 27d00133 Long Li 2018-10-31 3223 npages = (cur_len + start + PAGE_SIZE-1) / PAGE_SIZE; 27d00133 Long Li 2018-10-31 3224 rdata->page_offset = start; 27d00133 Long Li 2018-10-31 3225 rdata->tailsz = npages > 1 ? 27d00133 Long Li 2018-10-31 3226 cur_len-(PAGE_SIZE-start)-(npages-2)*PAGE_SIZE : 27d00133 Long Li 2018-10-31 3227 cur_len; 27d00133 Long Li 2018-10-31 3228 27d00133 Long Li 2018-10-31 3229 } else { 27d00133 Long Li 2018-10-31 3230 27d00133 Long Li 2018-10-31 3231 npages = DIV_ROUND_UP(cur_len, PAGE_SIZE); 1c892549 Jeff Layton 2012-05-16 3232 /* allocate a readdata struct */ 1c892549 Jeff Layton 2012-05-16 3233 rdata = cifs_readdata_alloc(npages, 1c892549 Jeff Layton 2012-05-16 3234 cifs_uncached_readv_complete); 1c892549 Jeff Layton 2012-05-16 3235 if (!rdata) { bed9da02 Pavel Shilovsky 2014-06-25 3236 add_credits_and_wake_if(server, credits, 0); 1c892549 Jeff Layton 2012-05-16 3237 rc = -ENOMEM; bae9f746 Jeff Layton 2014-04-15 3238 break; ^1da177e Linus Torvalds 2005-04-16 3239 } 1c892549 Jeff Layton 2012-05-16 3240 c5fab6f4 Jeff Layton 2012-09-19 3241 rc = cifs_read_allocate_pages(rdata, npages); 1c892549 Jeff Layton 2012-05-16 3242 if (rc) 1c892549 Jeff Layton 2012-05-16 3243 goto error; 1c892549 Jeff Layton 2012-05-16 3244 27d00133 Long Li 2018-10-31 3245 rdata->tailsz = PAGE_SIZE; 27d00133 Long Li 2018-10-31 3246 } 27d00133 Long Li 2018-10-31 3247 1c892549 Jeff Layton 2012-05-16 3248 rdata->cfile = cifsFileInfo_get(open_file); c5fab6f4 Jeff Layton 2012-09-19 3249 rdata->nr_pages = npages; 1c892549 Jeff Layton 2012-05-16 3250 rdata->offset = offset; 1c892549 Jeff Layton 2012-05-16 3251 rdata->bytes = cur_len; 1c892549 Jeff Layton 2012-05-16 3252 rdata->pid = pid; 8321fec4 Jeff Layton 2012-09-19 3253 rdata->pagesz = PAGE_SIZE; 8321fec4 Jeff Layton 2012-09-19 3254 rdata->read_into_pages = cifs_uncached_read_into_pages; d70b9104 Pavel Shilovsky 2016-11-17 3255 rdata->copy_into_pages = cifs_uncached_copy_into_pages; bed9da02 Pavel Shilovsky 2014-06-25 3256 rdata->credits = credits; 6685c5e2 Pavel Shilovsky 2017-04-25 3257 rdata->ctx = ctx; 6685c5e2 Pavel Shilovsky 2017-04-25 3258 kref_get(&ctx->refcount); 1c892549 Jeff Layton 2012-05-16 3259 25f40259 Pavel Shilovsky 2014-06-25 3260 if (!rdata->cfile->invalidHandle || 1fa839b4 Germano Percossi 2017-04-07 3261 !(rc = cifs_reopen_file(rdata->cfile, true))) 25f40259 Pavel Shilovsky 2014-06-25 3262 rc = server->ops->async_readv(rdata); 1c892549 Jeff Layton 2012-05-16 3263 error: 1c892549 Jeff Layton 2012-05-16 3264 if (rc) { bed9da02 Pavel Shilovsky 2014-06-25 3265 add_credits_and_wake_if(server, rdata->credits, 0); 1c892549 Jeff Layton 2012-05-16 3266 kref_put(&rdata->refcount, 1c892549 Jeff Layton 2012-05-16 3267 cifs_uncached_readdata_release); 27d00133 Long Li 2018-10-31 3268 if (rc == -EAGAIN) { 27d00133 Long Li 2018-10-31 3269 iov_iter_revert(&direct_iov, cur_len); 25f40259 Pavel Shilovsky 2014-06-25 3270 continue; 27d00133 Long Li 2018-10-31 3271 } ^1da177e Linus Torvalds 2005-04-16 3272 break; ^1da177e Linus Torvalds 2005-04-16 3273 } 1c892549 Jeff Layton 2012-05-16 3274 0ada36b2 Pavel Shilovsky 2014-06-25 3275 list_add_tail(&rdata->list, rdata_list); 1c892549 Jeff Layton 2012-05-16 3276 offset += cur_len; 1c892549 Jeff Layton 2012-05-16 3277 len -= cur_len; 1c892549 Jeff Layton 2012-05-16 3278 } while (len > 0); 1c892549 Jeff Layton 2012-05-16 3279 0ada36b2 Pavel Shilovsky 2014-06-25 3280 return rc; 0ada36b2 Pavel Shilovsky 2014-06-25 3281 } 0ada36b2 Pavel Shilovsky 2014-06-25 3282 --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation