[RFC v2 18/43] kexec: PKRAM: avoid clobbering already preserved pages
From: Anthony Yznaga <hidden>
Date: 2021-03-30 21:28:07
Also in:
kexec, linux-doc, linux-fsdevel, lkml
Subsystem:
kexec, the rest · Maintainers:
Andrew Morton, Baoquan He, Mike Rapoport, Pasha Tatashin, Pratyush Yadav, Linus Torvalds
Ensure destination ranges of the kexec segments do not overlap with any kernel pages marked to be preserved across kexec. For kexec_load, return EADDRNOTAVAIL if overlap is detected. For kexec_file_load, skip ranges containing preserved pages when seaching for available ranges to use. Signed-off-by: Anthony Yznaga <redacted> --- kernel/kexec_core.c | 3 +++ kernel/kexec_file.c | 5 +++++ 2 files changed, 8 insertions(+)
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index a0b6780740c8..fda4abb865ff 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c@@ -37,6 +37,7 @@ #include <linux/compiler.h> #include <linux/hugetlb.h> #include <linux/objtool.h> +#include <linux/pkram.h> #include <asm/page.h> #include <asm/sections.h>
@@ -175,6 +176,8 @@ int sanity_check_segment_list(struct kimage *image) return -EADDRNOTAVAIL; if (mend >= KEXEC_DESTINATION_MEMORY_LIMIT) return -EADDRNOTAVAIL; + if (pkram_has_preserved_pages(mstart, mend)) + return -EADDRNOTAVAIL; } /* Verify our destination addresses do not overlap.
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 1ec47a3c60dd..94109bcdbeff 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c@@ -516,6 +516,11 @@ static int locate_mem_hole_bottom_up(unsigned long start, unsigned long end, continue; } + if (pkram_has_preserved_pages(temp_start, temp_end + 1)) { + temp_start = temp_start - PAGE_SIZE; + continue; + } + /* We found a suitable memory range */ break; } while (1);
--
1.8.3.1