From: Paul Durrant <pdurrant@amazon.com>
Date: Thu, 28 May 2020 15:13:30 +0000 (+0100)
Subject: libxl: stop libxl_domain_info() consuming massive amounts of stack
X-Git-Tag: archive/raspbian/4.14.0+80-gd101b417b7-1+rpi1^2~63^2~117
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=2c4b1a7efb15292c0360f305b64581ac135ab8f2;p=xen.git

libxl: stop libxl_domain_info() consuming massive amounts of stack

Currently an array of 1024 xc_domaininfo_t is declared on stack. That alone
consumes ~112k. Since libxl_domain_info() creates a new gc this patch simply
uses it to allocate the array instead.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Reviewed-by: Ian Jackson <ian.jackson@eu.citrix.com>
---

diff --git a/tools/libxl/libxl_domain.c b/tools/libxl/libxl_domain.c
index c08af308fa..39f08a6519 100644
--- a/tools/libxl/libxl_domain.c
+++ b/tools/libxl/libxl_domain.c
@@ -314,11 +314,13 @@ libxl_dominfo * libxl_list_domain(libxl_ctx *ctx, int *nb_domain_out)
 {
     libxl_dominfo *ptr = NULL;
     int i, ret;
-    xc_domaininfo_t info[1024];
+    xc_domaininfo_t *info;
     int size = 0;
     uint32_t domid = 0;
     GC_INIT(ctx);
 
+    GCNEW_ARRAY(info, 1024);
+
     while ((ret = xc_domain_getinfolist(ctx->xch, domid, 1024, info)) > 0) {
         ptr = libxl__realloc(NOGC, ptr, (size + ret) * sizeof(libxl_dominfo));
         for (i = 0; i < ret; i++) {