[PATCH 0/1] MR2943: loader: In macOS preloader, reserve top-down heap space for Wow64.

[Tim Clem (＠tclem)]

This region is currently only reserved for 32-bit processes, which puts Wow64 at a disadvantage. The larger address space means it's not often an issue, but it's better to be explicit. Adding the reservation also causes ntdll/unix/virtual.c to consider that region first when making Wow64 allocations, before continuing through to the lower reservations. (And that's important for, e.g., changes like MR !2879.)

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https://gitlab.winehq.org/wine/wine/-/merge_requests/2943

[PATCH 1/1] loader: In macOS preloader, reserve top-down heap space for Wow64.

[Tim Clem]

From: Tim Clem <tclem(a)codeweavers.com>

---
 loader/preloader_mac.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/loader/preloader_mac.c b/loader/preloader_mac.c
index 8e249a7dc4d..817a91779ed 100644
--- a/loader/preloader_mac.c
+++ b/loader/preloader_mac.c
@@ -90,11 +90,11 @@ static struct wine_preload_info preload_info[] =
     { (void *)0x00001000, 0x0000f000 },  /* low 64k */
     { (void *)0x00010000, 0x00100000 },  /* DOS area */
     { (void *)0x00110000, 0x67ef0000 },  /* low memory area */
-    { (void *)0x7f000000, 0x03000000 },  /* top-down allocations + shared heap + virtual heap */
+    { (void *)0x7f000000, 0x03000000 },  /* shared user data and top-down allocations + shared heap + virtual heap */
 #else  /* __i386__ */
     { (void *)0x000000010000, 0x00100000 },  /* DOS area */
     { (void *)0x000000110000, 0x67ef0000 },  /* low memory area */
-    { (void *)0x00007ff00000, 0x000f0000 },  /* shared user data */
+    { (void *)0x00007f000000, 0x03000000 },  /* shared user data and Wow64 top-down allocations + shared heap + virtual heap */
     { (void *)0x000100000000, 0x14000000 },  /* WINE_4GB_RESERVE section */
     { (void *)0x7ff000000000, 0x01ff0000 },  /* top-down allocations + virtual heap */
 #endif /* __i386__ */
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/2943