From d90655390f5192d53723023667b57453ba23e676 Mon Sep 17 00:00:00 2001
From: Alex Lapenkou <lapenkov@fb.com>
Date: Mon, 22 Nov 2021 16:57:56 -0800
Subject: [PATCH] San: Create a function for committing and zeroing

Committing and zeroing an extent is usually done together, hence a new
function.
---
 include/jemalloc/internal/extent.h |  4 ++-
 src/extent.c                       | 56 +++++++++++++++++++-----------
 src/san_bump.c                     | 19 +++-------
 3 files changed, 43 insertions(+), 36 deletions(-)

diff --git a/include/jemalloc/internal/extent.h b/include/jemalloc/internal/extent.h
index 1660f45f..7336e8b8 100644
--- a/include/jemalloc/internal/extent.h
+++ b/include/jemalloc/internal/extent.h
@@ -43,7 +43,7 @@ void extent_dalloc_wrapper(tsdn_t *tsdn, pac_t *pac, ehooks_t *ehooks,
 void extent_destroy_wrapper(tsdn_t *tsdn, pac_t *pac, ehooks_t *ehooks,
     edata_t *edata);
 bool extent_commit_wrapper(tsdn_t *tsdn, ehooks_t *ehooks, edata_t *edata,
-    size_t offset, size_t length, bool growing_retained);
+    size_t offset, size_t length);
 bool extent_decommit_wrapper(tsdn_t *tsdn, ehooks_t *ehooks, edata_t *edata,
     size_t offset, size_t length);
 bool extent_purge_lazy_wrapper(tsdn_t *tsdn, ehooks_t *ehooks, edata_t *edata,
@@ -55,6 +55,8 @@ edata_t *extent_split_wrapper(tsdn_t *tsdn, pac_t *pac,
     bool holding_core_locks);
 bool extent_merge_wrapper(tsdn_t *tsdn, pac_t *pac, ehooks_t *ehooks,
     edata_t *a, edata_t *b);
+bool extent_commit_zero(tsdn_t *tsdn, ehooks_t *ehooks, edata_t *edata,
+    bool commit, bool zero, bool growing_retained);
 size_t extent_sn_next(pac_t *pac);
 bool extent_boot(void);
 
diff --git a/src/extent.c b/src/extent.c
index 6fabcc7d..4bbbff38 100644
--- a/src/extent.c
+++ b/src/extent.c
@@ -604,26 +604,20 @@ extent_recycle(tsdn_t *tsdn, pac_t *pac, ehooks_t *ehooks, ecache_t *ecache,
 		return NULL;
 	}
 
-	if (*commit && !edata_committed_get(edata)) {
-		if (extent_commit_impl(tsdn, ehooks, edata, 0,
-		    edata_size_get(edata), growing_retained)) {
-			extent_record(tsdn, pac, ehooks, ecache, edata);
-			return NULL;
-		}
-	}
-
-	if (edata_committed_get(edata)) {
-		*commit = true;
-	}
-
 	assert(edata_state_get(edata) == extent_state_active);
-
-	if (zero) {
-		void *addr = edata_base_get(edata);
-		if (!edata_zeroed_get(edata)) {
-			size_t size = edata_size_get(edata);
-			ehooks_zero(tsdn, ehooks, addr, size);
-		}
+	if (extent_commit_zero(tsdn, ehooks, edata, *commit, zero,
+	    growing_retained)) {
+		extent_record(tsdn, pac, ehooks, ecache, edata);
+		return NULL;
+	}
+	if (edata_committed_get(edata)) {
+		/*
+		 * This reverses the purpose of this variable - previously it
+		 * was treated as an input parameter, now it turns into an
+		 * output parameter, reporting if the edata has actually been
+		 * committed.
+		 */
+		*commit = true;
 	}
 	return edata;
 }
@@ -1106,9 +1100,9 @@ extent_commit_impl(tsdn_t *tsdn, ehooks_t *ehooks, edata_t *edata,
 
 bool
 extent_commit_wrapper(tsdn_t *tsdn, ehooks_t *ehooks, edata_t *edata,
-    size_t offset, size_t length, bool growing_retained) {
+    size_t offset, size_t length) {
 	return extent_commit_impl(tsdn, ehooks, edata, offset, length,
-	    growing_retained);
+	    /* growing_retained */ false);
 }
 
 bool
@@ -1287,6 +1281,26 @@ extent_merge_wrapper(tsdn_t *tsdn, pac_t *pac, ehooks_t *ehooks,
 	    /* holding_core_locks */ false);
 }
 
+bool
+extent_commit_zero(tsdn_t *tsdn, ehooks_t *ehooks, edata_t *edata,
+    bool commit, bool zero, bool growing_retained) {
+	witness_assert_depth_to_rank(tsdn_witness_tsdp_get(tsdn),
+	    WITNESS_RANK_CORE, growing_retained ? 1 : 0);
+
+	if (commit && !edata_committed_get(edata)) {
+		if (extent_commit_impl(tsdn, ehooks, edata, 0,
+		    edata_size_get(edata), growing_retained)) {
+			return true;
+		}
+	}
+	if (zero && !edata_zeroed_get(edata)) {
+		void *addr = edata_base_get(edata);
+		size_t size = edata_size_get(edata);
+		ehooks_zero(tsdn, ehooks, addr, size);
+	}
+	return false;
+}
+
 bool
 extent_boot(void) {
 	assert(sizeof(slab_data_t) >= sizeof(e_prof_info_t));
diff --git a/src/san_bump.c b/src/san_bump.c
index 1a94e55d..88897455 100644
--- a/src/san_bump.c
+++ b/src/san_bump.c
@@ -68,20 +68,11 @@ san_bump_alloc(tsdn_t *tsdn, san_bump_alloc_t* sba, pac_t *pac,
 	san_guard_pages(tsdn, ehooks, edata, pac->emap, /* left */ false,
 	    /* right */ true, /* remap */ true);
 
-	if (!edata_committed_get(edata)) {
-		if (extent_commit_wrapper(tsdn, ehooks, edata, 0,
-		    edata_size_get(edata), true)) {
-			extent_record(tsdn, pac, ehooks, &pac->ecache_retained,
-			    edata);
-			return NULL;
-		}
-		edata_committed_set(edata, true);
-	}
-	if (zero && !edata_zeroed_get(edata)) {
-		void *addr = edata_base_get(edata);
-		size_t size = edata_size_get(edata);
-		ehooks_zero(tsdn, ehooks, addr, size);
-		edata_zeroed_set(edata, true);
+	if (extent_commit_zero(tsdn, ehooks, edata, /* commit */ true, zero,
+	    /* growing_retained */ false)) {
+		extent_record(tsdn, pac, ehooks, &pac->ecache_retained,
+		    edata);
+		return NULL;
 	}
 
 	if (config_prof) {