From b238527664ec6f6c9d00dba4cc2f3dab1c8b8b04 Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Tue, 27 Nov 2018 10:07:03 -0800 Subject: [PATCH] Fix jit compilation bug on wide tables. The function generated to perform JIT compiled tuple deforming failed when HeapTupleHeader's t_hoff was bigger than a signed int8. I'd failed to realize that LLVM's getelementptr would treat an int8 index argument as signed, rather than unsigned. That means that a hoff larger than 127 would result in a negative offset being applied. Fix that by widening the index to 32bit. Add a testcase with a wide table. Don't drop it, as it seems useful to verify other tools deal properly with wide tables. Thanks to Justin Pryzby for both reporting a bug and then reducing it to a reproducible testcase! Reported-By: Justin Pryzby Author: Andres Freund Discussion: https://postgr.es/m/20181115223959.GB10913@telsasoft.com Backpatch: 11, just as jit compilation was --- src/backend/jit/llvm/llvmjit_deform.c | 12 +++++++++--- src/test/regress/expected/create_table.out | 10 ++++++++++ src/test/regress/expected/sanity_check.out | 1 + src/test/regress/sql/create_table.sql | 10 ++++++++++ 4 files changed, 30 insertions(+), 3 deletions(-) diff --git a/src/backend/jit/llvm/llvmjit_deform.c b/src/backend/jit/llvm/llvmjit_deform.c index 4111bf0a54..d168eae087 100644 --- a/src/backend/jit/llvm/llvmjit_deform.c +++ b/src/backend/jit/llvm/llvmjit_deform.c @@ -248,10 +248,16 @@ slot_compile_deform(LLVMJitContext *context, TupleDesc desc, v_infomask2, "maxatt"); + /* + * Need to zext, as getelementptr otherwise treats hoff as a signed 8bit + * integer, which'd yield a negative offset for t_hoff > 127. + */ v_hoff = - l_load_struct_gep(b, v_tuplep, - FIELDNO_HEAPTUPLEHEADERDATA_HOFF, - "t_hoff"); + LLVMBuildZExt(b, + l_load_struct_gep(b, v_tuplep, + FIELDNO_HEAPTUPLEHEADERDATA_HOFF, + ""), + LLVMInt32Type(), "t_hoff"); v_tupdata_base = LLVMBuildGEP(b, diff --git a/src/test/regress/expected/create_table.out b/src/test/regress/expected/create_table.out index e92748c1ea..b26b4e7b6d 100644 --- a/src/test/regress/expected/create_table.out +++ b/src/test/regress/expected/create_table.out @@ -261,6 +261,16 @@ ERROR: relation "as_select1" already exists CREATE TABLE IF NOT EXISTS as_select1 AS SELECT * FROM pg_class WHERE relkind = 'r'; NOTICE: relation "as_select1" already exists, skipping DROP TABLE as_select1; +-- create an extra wide table to test for issues related to that +-- (temporarily hide query, to avoid the long CREATE TABLE stmt) +\set ECHO none +INSERT INTO extra_wide_table(firstc, lastc) VALUES('first col', 'last col'); +SELECT firstc, lastc FROM extra_wide_table; + firstc | lastc +-----------+---------- + first col | last col +(1 row) + -- check that tables with oids cannot be created anymore CREATE TABLE withoid() WITH OIDS; ERROR: syntax error at or near "OIDS" diff --git a/src/test/regress/expected/sanity_check.out b/src/test/regress/expected/sanity_check.out index c77060d36c..009a89fc1a 100644 --- a/src/test/regress/expected/sanity_check.out +++ b/src/test/regress/expected/sanity_check.out @@ -44,6 +44,7 @@ dupindexcols|t e_star|f emp|f equipment_r|f +extra_wide_table|f f_star|f fast_emp4000|t float4_tbl|f diff --git a/src/test/regress/sql/create_table.sql b/src/test/regress/sql/create_table.sql index 90cc1a578f..c6f048f8c2 100644 --- a/src/test/regress/sql/create_table.sql +++ b/src/test/regress/sql/create_table.sql @@ -277,6 +277,16 @@ CREATE TABLE as_select1 AS SELECT * FROM pg_class WHERE relkind = 'r'; CREATE TABLE IF NOT EXISTS as_select1 AS SELECT * FROM pg_class WHERE relkind = 'r'; DROP TABLE as_select1; +-- create an extra wide table to test for issues related to that +-- (temporarily hide query, to avoid the long CREATE TABLE stmt) +\set ECHO none +SELECT 'CREATE TABLE extra_wide_table(firstc text, '|| array_to_string(array_agg('c'||i||' bool'),',')||', lastc text);' +FROM generate_series(1, 1100) g(i) +\gexec +\set ECHO all +INSERT INTO extra_wide_table(firstc, lastc) VALUES('first col', 'last col'); +SELECT firstc, lastc FROM extra_wide_table; + -- check that tables with oids cannot be created anymore CREATE TABLE withoid() WITH OIDS; CREATE TABLE withoid() WITH (oids);