From 7b44866a307a31052c8882a24c6ad613899cc9ce Mon Sep 17 00:00:00 2001 From: Jacob Champion Date: Mon, 17 Nov 2025 14:02:38 -0800 Subject: [PATCH v2 2/2] postgres: Use pg_{add,mul}_size_overflow() The backend implementations of add_size() and mul_size() can now make use of the APIs provided in common/int.h. Reviewed-by: Chao Li Reviewed-by: Michael Paquier Discussion: https://postgr.es/m/CAOYmi%2B%3D%2BpqUd2MUitvgW1pAJuXgG_TKCVc3_Ek7pe8z9nkf%2BAg%40mail.gmail.com --- src/backend/storage/ipc/shmem.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) diff --git a/src/backend/storage/ipc/shmem.c b/src/backend/storage/ipc/shmem.c index 0f18beb6ad4..ee3408df301 100644 --- a/src/backend/storage/ipc/shmem.c +++ b/src/backend/storage/ipc/shmem.c @@ -65,6 +65,7 @@ #include "postgres.h" +#include "common/int.h" #include "fmgr.h" #include "funcapi.h" #include "miscadmin.h" @@ -495,9 +496,7 @@ add_size(Size s1, Size s2) { Size result; - result = s1 + s2; - /* We are assuming Size is an unsigned type here... */ - if (result < s1 || result < s2) + if (pg_add_size_overflow(s1, s2, &result)) ereport(ERROR, (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED), errmsg("requested shared memory size overflows size_t"))); @@ -512,11 +511,7 @@ mul_size(Size s1, Size s2) { Size result; - if (s1 == 0 || s2 == 0) - return 0; - result = s1 * s2; - /* We are assuming Size is an unsigned type here... */ - if (result / s2 != s1) + if (pg_mul_size_overflow(s1, s2, &result)) ereport(ERROR, (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED), errmsg("requested shared memory size overflows size_t"))); -- 2.34.1