From: Mergen Imeev via Tarantool-patches <tarantool-patches@dev.tarantool.org> To: Vladislav Shpilevoy <v.shpilevoy@tarantool.org> Cc: tarantool-patches@dev.tarantool.org Subject: Re: [Tarantool-patches] [PATCH v1 1/1] sql: fix error on copy empty string in mem_copy() Date: Fri, 27 Aug 2021 18:22:23 +0300 [thread overview] Message-ID: <20210827152223.GA435770@tarantool.org> (raw) In-Reply-To: <40a89d61-e252-731c-d419-6c162eecefb4@tarantool.org> Thank you for the review! My answers and new patch below. I didn't include diff since I reworked most psrt of the patch. On Thu, Aug 26, 2021 at 10:21:01PM +0200, Vladislav Shpilevoy wrote: > Hi! Thanks for the patch! > > See 3 comments below. > > > diff --git a/test/sql-tap/gh-6157-unnecessary-free-on-string.c b/test/sql-tap/gh-6157-unnecessary-free-on-string.c > > new file mode 100644 > > index 000000000..ce928d494 > > --- /dev/null > > +++ b/test/sql-tap/gh-6157-unnecessary-free-on-string.c > > @@ -0,0 +1,10 @@ > > +#include "msgpuck.h" > > +#include "module.h" > > + > > +int > > +f(box_function_ctx_t* ctx, const char* args, const char* args_end) > > 1. '*' must be right before variable name, not after the types. > Dropped this funcion. > > +{ > > + char res[16]; > > + char *end = mp_encode_str(res, "stub", strlen("stub")); > > + return box_return_mp(ctx, res, end); > > +} > > 2. Why do you need a C function? Can't you reproduce it with Lua? > Dropped. > > diff --git a/test/sql-tap/gh-6157-unnecessary-free-on-string.test.lua b/test/sql-tap/gh-6157-unnecessary-free-on-string.test.lua > > new file mode 100755 > > index 000000000..326570aea > > --- /dev/null > > +++ b/test/sql-tap/gh-6157-unnecessary-free-on-string.test.lua > > @@ -0,0 +1,38 @@ > > +#!/usr/bin/env tarantool > > +local build_path = os.getenv("BUILDDIR") > > +package.cpath = build_path..'/test/sql-tap/?.so;'..build_path..'/test/sql-tap/?.dylib;'..package.cpath > > + > > +local test = require("sqltester") > > +test:plan(1) > > + > > +box.schema.func.create("gh-6157.f", { > > + language = "C", > > + param_list = {"string"}, > > + returns = "string", > > + exports = {"SQL"} > > +}) > > + > > +box.execute([[CREATE TABLE ts(s STRING PRIMARY KEY);]]) > > +box.execute([[INSERT INTO ts VALUES ('');]]) > > +box.execute([[CREATE TABLE ti(i INT PRIMARY KEY);]]) > > +for i = 1, 100 do > > + box.execute([[INSERT INTO ti VALUES(]]..i..[[);]]) > > 3. Why do you need a space to reproduce this bug? It does not seem related. As I understood, there is two bugs: first - seems like lookaside is leaking, but not sure if this is a bug. Created a new issue - #6401. The second is the one fixed in this patch. I reworked this test and now it is a lot simpler. Also, I added checks for the result of mem_copy() since before we couldn't be sure where exactly these errors appear, since only part of mem_copy() was executed, but error was set improperly. New patch: commit c7e823516c5fdf91ff9b04fc3a0642e3ced9ad3e Author: Mergen Imeev <imeevma@gmail.com> Date: Mon Aug 23 11:54:09 2021 +0300 sql: fix error on copy empty string in mem_copy() This patch fixes the problem with copying an empty string in mem_copy(). Previously, because the string length was 0, an error was thrown, but the diag was not set, which could lead to an error due to an empty diag or to a double free. Closes #6157 diff --git a/changelogs/unreleased/gh-6157-fix-error-on-copy-empty-str.md b/changelogs/unreleased/gh-6157-fix-error-on-copy-empty-str.md new file mode 100644 index 000000000..e5f747414 --- /dev/null +++ b/changelogs/unreleased/gh-6157-fix-error-on-copy-empty-str.md @@ -0,0 +1,5 @@ +## bugfix/sql + +* Now, when copying an empty string, an error will not be set + unnecessarily (gh-6157). + diff --git a/src/box/sql/func.c b/src/box/sql/func.c index c063552d6..9009f9e4f 100644 --- a/src/box/sql/func.c +++ b/src/box/sql/func.c @@ -1771,13 +1771,15 @@ minmaxStep(sql_context * context, int NotUsed, sql_value ** argv) bool is_max = (func->flags & SQL_FUNC_MAX) != 0; int cmp = mem_cmp_scalar(pBest, pArg, pColl); if ((is_max && cmp < 0) || (!is_max && cmp > 0)) { - mem_copy(pBest, pArg); + if (mem_copy(pBest, pArg) != 0) + context->is_aborted = true; } else { sqlSkipAccumulatorLoad(context); } } else { pBest->db = sql_context_db_handle(context); - mem_copy(pBest, pArg); + if (mem_copy(pBest, pArg) != 0) + context->is_aborted = true; } } diff --git a/src/box/sql/mem.c b/src/box/sql/mem.c index 4c40f15dc..819d9b094 100644 --- a/src/box/sql/mem.c +++ b/src/box/sql/mem.c @@ -1913,7 +1913,8 @@ mem_copy(struct Mem *to, const struct Mem *from) assert((to->flags & MEM_Zero) == 0 || to->type == MEM_TYPE_BIN); if ((to->flags & MEM_Zero) != 0) return sqlVdbeMemExpandBlob(to); - to->zMalloc = sqlDbReallocOrFree(to->db, to->zMalloc, to->n); + to->zMalloc = sqlDbRealloc(to->db, to->zMalloc, MAX(32, to->n)); + assert(to->zMalloc != NULL || sql_get()->mallocFailed != 0); if (to->zMalloc == NULL) return -1; to->szMalloc = sqlDbMallocSize(to->db, to->zMalloc); diff --git a/src/box/sql/vdbe.c b/src/box/sql/vdbe.c index 7f86fa7b3..44533fb3e 100644 --- a/src/box/sql/vdbe.c +++ b/src/box/sql/vdbe.c @@ -978,7 +978,8 @@ case OP_Copy: { pOut = &aMem[pOp->p2]; assert(pOut!=pIn1); while( 1) { - mem_copy(pOut, pIn1); + if (mem_copy(pOut, pIn1) != 0) + goto abort_due_to_error; REGISTER_TRACE(p, pOp->p2+pOp->p3-n, pOut); if ((n--)==0) break; pOut++; diff --git a/src/box/sql/vdbeapi.c b/src/box/sql/vdbeapi.c index 8031ee0dc..e44d73a16 100644 --- a/src/box/sql/vdbeapi.c +++ b/src/box/sql/vdbeapi.c @@ -232,7 +232,8 @@ sql_result_text64(sql_context * pCtx, void sql_result_value(sql_context * pCtx, sql_value * pValue) { - mem_copy(pCtx->pOut, pValue); + if (mem_copy(pCtx->pOut, pValue) != 0) + pCtx->is_aborted = true; } void diff --git a/src/box/sql/vdbeaux.c b/src/box/sql/vdbeaux.c index 2d7800b17..beb8cee04 100644 --- a/src/box/sql/vdbeaux.c +++ b/src/box/sql/vdbeaux.c @@ -2318,8 +2318,12 @@ sqlVdbeGetBoundValue(struct Vdbe *v, int iVar) Mem *pMem = &v->aVar[iVar - 1]; if (!mem_is_null(pMem)) { sql_value *pRet = sqlValueNew(v->db); - if (pRet != NULL) - mem_copy(pRet, pMem); + if (pRet == NULL) + return NULL; + if (mem_copy(pRet, pMem) != 0) { + sqlDbFree(sql_get(), pRet); + return NULL; + } return pRet; } } diff --git a/test/sql-tap/engine.cfg b/test/sql-tap/engine.cfg index 587adbed9..c35d1dced 100644 --- a/test/sql-tap/engine.cfg +++ b/test/sql-tap/engine.cfg @@ -35,6 +35,7 @@ "built-in-functions.test.lua": { "memtx": {"engine": "memtx"} }, + "gh-6157-unnecessary-free-on-string.test.lua": {}, "gh-4077-iproto-execute-no-bind.test.lua": {}, "gh-6375-assert-on-unsupported-ext.test.lua": {}, "*": { diff --git a/test/sql-tap/gh-6157-unnecessary-free-on-string.test.lua b/test/sql-tap/gh-6157-unnecessary-free-on-string.test.lua new file mode 100755 index 000000000..e0c09a325 --- /dev/null +++ b/test/sql-tap/gh-6157-unnecessary-free-on-string.test.lua @@ -0,0 +1,18 @@ +#!/usr/bin/env tarantool +local tap = require('tap') +local test = tap.test('test wrong error in mem_copy()') + +-- +-- Make sure there is no assert due to an incorrectly set error in mem_copy(). +-- How this test works: We have 128 mempool cells in SQL ("lookaside"), and +-- until those 128 cells are filled in, the error cannot be reproduced. Also, we +-- have to get '' from somewhere because if we just enter it, it will be of type +-- STATIC and no memory will be allocated. +-- +local s = "NULLIF(SUBSTR('123', 1, 0), NULL)" +for i = 1, 5 do s = s..', '..s end +local res = box.execute("SELECT "..s).rows[1] + +test:plan(1) +test:is(#res, 32, 'wrong error in mem_copy() was set') +os.exit(test:check() and 0 or 1)
next prev parent reply other threads:[~2021-08-27 15:22 UTC|newest] Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-08-26 11:09 Mergen Imeev via Tarantool-patches 2021-08-26 20:21 ` Vladislav Shpilevoy via Tarantool-patches 2021-08-27 15:22 ` Mergen Imeev via Tarantool-patches [this message] 2021-08-27 21:44 ` Vladislav Shpilevoy via Tarantool-patches 2021-08-30 5:57 ` Mergen Imeev via Tarantool-patches 2021-08-30 21:32 ` Vladislav Shpilevoy via Tarantool-patches 2021-08-31 8:55 ` Mergen Imeev via Tarantool-patches 2021-09-01 21:34 ` Vladislav Shpilevoy via Tarantool-patches 2021-09-02 8:43 Mergen Imeev via Tarantool-patches 2021-09-02 9:15 ` Timur Safin via Tarantool-patches 2021-09-02 9:35 ` Mergen Imeev via Tarantool-patches 2021-09-02 9:17 ` Timur Safin via Tarantool-patches
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