diff options
| author | Baoquan He <bhe@redhat.com> | 2019-05-24 09:38:09 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2019-06-28 07:14:59 +0200 |
| commit | ee338b9ee2822e65a85750da6129946c14962410 (patch) | |
| tree | 3c1e8e5ab7c4e1540b4bd5b755523f3d07a614e1 /arch/x86/kernel/kexec-bzimage64.c | |
| parent | x86/boot: Add xloadflags bits to check for 5-level paging support (diff) | |
| download | linux-ee338b9ee2822e65a85750da6129946c14962410.tar.xz linux-ee338b9ee2822e65a85750da6129946c14962410.zip | |
x86/kexec/64: Prevent kexec from 5-level paging to a 4-level only kernel
If the running kernel has 5-level paging activated, the 5-level paging mode
is preserved across kexec. If the kexec'ed kernel does not contain support
for handling active 5-level paging mode in the decompressor, the
decompressor will crash with #GP.
Prevent this situation at load time. If 5-level paging is active, check the
xloadflags whether the kexec kernel can handle 5-level paging at least in
the decompressor. If not, reject the load attempt and print out an error
message.
Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: bp@alien8.de
Cc: hpa@zytor.com
Cc: dyoung@redhat.com
Link: https://lkml.kernel.org/r/20190524073810.24298-3-bhe@redhat.com
Diffstat (limited to 'arch/x86/kernel/kexec-bzimage64.c')
| -rw-r--r-- | arch/x86/kernel/kexec-bzimage64.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c index 22f60dd26460..7f439739ea3d 100644 --- a/arch/x86/kernel/kexec-bzimage64.c +++ b/arch/x86/kernel/kexec-bzimage64.c @@ -321,6 +321,11 @@ static int bzImage64_probe(const char *buf, unsigned long len) return ret; } + if (!(header->xloadflags & XLF_5LEVEL) && pgtable_l5_enabled()) { + pr_err("bzImage cannot handle 5-level paging mode.\n"); + return ret; + } + /* I've got a bzImage */ pr_debug("It's a relocatable bzImage64\n"); ret = 0; |