git: 2870493f1f55 - main - kboot: Properly cap number of segments loaded for kexec

From: Warner Losh <imp_at_FreeBSD.org>
Date: Fri, 15 Jul 2022 18:04:07 UTC
The branch main has been updated by imp:

URL: https://cgit.FreeBSD.org/src/commit/?id=2870493f1f55d5c00e5593f336dc05805863db7f

commit 2870493f1f55d5c00e5593f336dc05805863db7f
Author:     Warner Losh <imp@FreeBSD.org>
AuthorDate: 2022-06-29 22:31:23 +0000
Commit:     Warner Losh <imp@FreeBSD.org>
CommitDate: 2022-07-15 18:00:51 +0000

    kboot: Properly cap number of segments loaded for kexec
    
    Linux has an arbitrary limit of 16 segments. Make sure we don't load too
    many.
    
    Sponsored by:           Netflix
---
 stand/kboot/main.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/stand/kboot/main.c b/stand/kboot/main.c
index 79c03398ba6d..83ad0ceb8a18 100644
--- a/stand/kboot/main.c
+++ b/stand/kboot/main.c
@@ -340,15 +340,17 @@ time(time_t *tloc)
 	return (rv);
 }
 
-struct host_kexec_segment loaded_segments[128];
+struct host_kexec_segment loaded_segments[HOST_KEXEC_SEGMENT_MAX];
 int nkexec_segments = 0;
 
 static ssize_t
 get_phys_buffer(vm_offset_t dest, const size_t len, void **buf)
 {
 	int i = 0;
-	const size_t segsize = 4*1024*1024;
+	const size_t segsize = 8*1024*1024;
 
+	if (nkexec_segments == HOST_KEXEC_SEGMENT_MAX)
+		panic("Tried to load too many kexec segments");
 	for (i = 0; i < nkexec_segments; i++) {
 		if (dest >= (vm_offset_t)loaded_segments[i].mem &&
 		    dest < (vm_offset_t)loaded_segments[i].mem +