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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2020-07-20 15:54:24 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2020-07-20 15:54:24 -0400 |
| commit | 855195a7ba9875648f958c42aba91ad382e82edd (patch) | |
| tree | 515be2f2c669c388b7dda9704e1d3db90b0dc42c /src/backend/jit/llvm/llvmjit_deform.c | |
| parent | e8de627a3e05e201ffb78ad7792d14fd25c857c8 (diff) | |
| download | postgresql-855195a7ba9875648f958c42aba91ad382e82edd.tar.gz postgresql-855195a7ba9875648f958c42aba91ad382e82edd.zip | |
Kluge slot_compile_deform() to ignore incorrect attnotnull markings.
Since we mustn't force an initdb in released branches, there is no
simple way to correct the markings of pg_subscription.subslotname
and pg_subscription_rel.srsublsn as attnotnull in existing pre-v13
installations.
Fortunately, released branches don't rely on attnotnull being correct
for much. The planner looks at it in relation_excluded_by_constraints,
but it'd be difficult to get that to matter for a query on a system
catalog. The only place where it's really problematic is in JIT's
slot_compile_deform(), which can produce incorrect code that crashes
if there are NULLs in an allegedly not-null column.
Hence, hack up slot_compile_deform() to be specifically aware of
these two incorrect markings and not trust them.
This applies to v11 and v12; the JIT code didn't exist before that,
and we've fixed the markings in v13.
Discussion: https://postgr.es/m/229396.1595191345@sss.pgh.pa.us
Diffstat (limited to 'src/backend/jit/llvm/llvmjit_deform.c')
| -rw-r--r-- | src/backend/jit/llvm/llvmjit_deform.c | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/src/backend/jit/llvm/llvmjit_deform.c b/src/backend/jit/llvm/llvmjit_deform.c index e406d392d4e..6384ac940d8 100644 --- a/src/backend/jit/llvm/llvmjit_deform.c +++ b/src/backend/jit/llvm/llvmjit_deform.c @@ -22,12 +22,28 @@ #include "access/htup_details.h" #include "access/tupdesc_details.h" +#include "catalog/pg_subscription.h" +#include "catalog/pg_subscription_rel.h" #include "executor/tuptable.h" #include "jit/llvmjit.h" #include "jit/llvmjit_emit.h" /* + * Through an embarrassing oversight, pre-v13 installations may have + * pg_subscription.subslotname and pg_subscription_rel.srsublsn marked as + * attnotnull, which they should not be. To avoid possible crashes, use + * this macro instead of testing attnotnull directly. + */ +#define ATTNOTNULL(att) \ + ((att)->attnotnull && \ + !(((att)->attrelid == SubscriptionRelationId && \ + (att)->attnum == Anum_pg_subscription_subslotname) || \ + ((att)->attrelid == SubscriptionRelRelationId && \ + (att)->attnum == Anum_pg_subscription_rel_srsublsn))) + + +/* * Create a function that deforms a tuple of type desc up to natts columns. */ LLVMValueRef @@ -113,7 +129,7 @@ slot_compile_deform(LLVMJitContext *context, TupleDesc desc, int natts) * it's guaranteed that all columns up to here exist at least in the * NULL bitmap. */ - if (att->attnotnull) + if (ATTNOTNULL(att)) guaranteed_column_number = attnum; } @@ -376,7 +392,7 @@ slot_compile_deform(LLVMJitContext *context, TupleDesc desc, int natts) * into account, because in case they're present the heaptuple's natts * would have indicated that a slot_getmissingattrs() is needed. */ - if (!att->attnotnull) + if (!ATTNOTNULL(att)) { LLVMBasicBlockRef b_ifnotnull; LLVMBasicBlockRef b_ifnull; @@ -557,7 +573,7 @@ slot_compile_deform(LLVMJitContext *context, TupleDesc desc, int natts) known_alignment = -1; attguaranteedalign = false; } - else if (att->attnotnull && attguaranteedalign && known_alignment >= 0) + else if (ATTNOTNULL(att) && attguaranteedalign && known_alignment >= 0) { /* * If the offset to the column was previously known a NOT NULL & @@ -567,7 +583,7 @@ slot_compile_deform(LLVMJitContext *context, TupleDesc desc, int natts) Assert(att->attlen > 0); known_alignment += att->attlen; } - else if (att->attnotnull && (att->attlen % alignto) == 0) + else if (ATTNOTNULL(att) && (att->attlen % alignto) == 0) { /* * After a NOT NULL fixed-width column with a length that is a |