git.postgresql.org Git - postgresql.git/commitdiff

git projects / postgresql.git / commitdiff

pageinspect: Fix unaligned struct access in GIN functions

author Peter Eisentraut <peter_e@gmx.net>

Fri, 4 Nov 2016 16:00:00 +0000 (12:00 -0400)

committer Peter Eisentraut <peter_e@gmx.net>

Fri, 4 Nov 2016 14:05:37 +0000 (10:05 -0400)

The raw page data that is passed into the functions will not be aligned
at 8-byte boundaries. Casting that to a struct and accessing int64
fields will result in unaligned access. On most platforms, you get away
with it, but it will result on a crash on pickier platforms such as ia64
and sparc64.

contrib/pageinspect/ginfuncs.c patch | blob | blame | history

diff --git a/contrib/pageinspect/ginfuncs.c b/contrib/pageinspect/ginfuncs.c

index 145e2ce709cc6d3a8732ebd4d89a3023165599de..6e4103df6a96e19562252c99195c37daed1477b5 100644 (file)

--- a/contrib/pageinspect/ginfuncs.c

+++ b/contrib/pageinspect/ginfuncs.c

@@ -28,11 +28,31 @@ PG_FUNCTION_INFO_V1(gin_metapage_info);

PG_FUNCTION_INFO_V1(gin_page_opaque_info);

PG_FUNCTION_INFO_V1(gin_leafpage_items);

+static Page

+get_page_from_raw(bytea *raw_page)

+ int raw_page_size;

+ Page page;

+ raw_page_size = VARSIZE(raw_page) - VARHDRSZ;

+ if (raw_page_size < BLCKSZ)

+ ereport(ERROR,

+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),

+ errmsg("input page too small (%d bytes)", raw_page_size)));

+ /* make a copy so that the page is properly aligned for struct access */

+ page = palloc(raw_page_size);

+ memcpy(page, VARDATA(raw_page), raw_page_size);

+ return page;

Datum

gin_metapage_info(PG_FUNCTION_ARGS)

{

bytea *raw_page = PG_GETARG_BYTEA_P(0);

- int raw_page_size;

TupleDesc tupdesc;

Page page;

GinPageOpaque opaq;

@@ -46,12 +66,7 @@ gin_metapage_info(PG_FUNCTION_ARGS)

(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),

(errmsg("must be superuser to use raw page functions"))));

- raw_page_size = VARSIZE(raw_page) - VARHDRSZ;

- if (raw_page_size < BLCKSZ)

- ereport(ERROR,

- (errcode(ERRCODE_INVALID_PARAMETER_VALUE),

- errmsg("input page too small (%d bytes)", raw_page_size)));

- page = VARDATA(raw_page);

+ page = get_page_from_raw(raw_page);

opaq = (GinPageOpaque) PageGetSpecialPointer(page);

if (opaq->flags != GIN_META)

@@ -94,7 +109,6 @@ Datum

gin_page_opaque_info(PG_FUNCTION_ARGS)

{

bytea *raw_page = PG_GETARG_BYTEA_P(0);

- int raw_page_size;

TupleDesc tupdesc;

Page page;

GinPageOpaque opaq;

@@ -110,12 +124,7 @@ gin_page_opaque_info(PG_FUNCTION_ARGS)

(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),

(errmsg("must be superuser to use raw page functions"))));

- raw_page_size = VARSIZE(raw_page) - VARHDRSZ;

- if (raw_page_size < BLCKSZ)

- ereport(ERROR,

- (errcode(ERRCODE_INVALID_PARAMETER_VALUE),

- errmsg("input page too small (%d bytes)", raw_page_size)));

- page = VARDATA(raw_page);

+ page = get_page_from_raw(raw_page);

opaq = (GinPageOpaque) PageGetSpecialPointer(page);

@@ -173,7 +182,6 @@ Datum

gin_leafpage_items(PG_FUNCTION_ARGS)

{

bytea *raw_page = PG_GETARG_BYTEA_P(0);

- int raw_page_size;

FuncCallContext *fctx;

gin_leafpage_items_state *inter_call_data;

@@ -182,8 +190,6 @@ gin_leafpage_items(PG_FUNCTION_ARGS)

(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),

(errmsg("must be superuser to use raw page functions"))));

- raw_page_size = VARSIZE(raw_page) - VARHDRSZ;

if (SRF_IS_FIRSTCALL())

{

TupleDesc tupdesc;

@@ -191,11 +197,7 @@ gin_leafpage_items(PG_FUNCTION_ARGS)

Page page;

GinPageOpaque opaq;

- if (raw_page_size < BLCKSZ)

- ereport(ERROR,

- (errcode(ERRCODE_INVALID_PARAMETER_VALUE),

- errmsg("input page too small (%d bytes)", raw_page_size)));

- page = VARDATA(raw_page);

+ page = get_page_from_raw(raw_page);

if (PageGetSpecialSize(page) != MAXALIGN(sizeof(GinPageOpaqueData)))

ereport(ERROR,

This is the main PostgreSQL git repository.

RSS Atom