x86/kexec: Fix a kexec_file_load() failure

Commit

  b6664ba42f14 ("s390, kexec_file: drop arch_kexec_mem_walk()")

changed the behavior of kexec_locate_mem_hole(): it will try to allocate
free memory only when kbuf.mem is initialized to zero.

However, x86's kexec_file_load() implementation reuses a struct
kexec_buf allocated on the stack and its kbuf.mem member gets set by
each kexec_add_buffer() invocation.

The second kexec_add_buffer() will reuse the same kbuf but not
reinitialize kbuf.mem.

Therefore, explictily reset kbuf.mem each time in order for
kexec_locate_mem_hole() to locate a free memory region each time.

 [ bp: massage commit message. ]

Fixes: b6664ba42f14 ("s390, kexec_file: drop arch_kexec_mem_walk()")
Signed-off-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Philipp Rudo <prudo@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Yannik Sembritzki <yannik@sembritzki.me>
Cc: Yi Wang <wang.yi59@zte.com.cn>
Cc: kexec@lists.infradead.org
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20181228011247.GA9999@dhcp-128-65.nay.redhat.com

diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index c8b07d8ea5a2bba61448b169a0cd0ea3daa086ad..17ffc869cab822d03e85baea56bade232a0e4598 100644 (file)
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -470,6 +470,7 @@ int crash_load_segments(struct kimage *image)
 
        kbuf.memsz = kbuf.bufsz;
        kbuf.buf_align = ELF_CORE_HEADER_ALIGN;
+       kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
        ret = kexec_add_buffer(&kbuf);
        if (ret) {
                vfree((void *)image->arch.elf_headers);

diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c
index 278cd07228dd886778cabf708dd2b1237a318d72..0d5efa34f35966f0b272797f737252ed8bdb23a6 100644 (file)
--- a/arch/x86/kernel/kexec-bzimage64.c
+++ b/arch/x86/kernel/kexec-bzimage64.c
@@ -434,6 +434,7 @@ static void *bzImage64_load(struct kimage *image, char *kernel,
        kbuf.memsz = PAGE_ALIGN(header->init_size);
        kbuf.buf_align = header->kernel_alignment;
        kbuf.buf_min = MIN_KERNEL_LOAD_ADDR;
+       kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
        ret = kexec_add_buffer(&kbuf);
        if (ret)
                goto out_free_params;
@@ -448,6 +449,7 @@ static void *bzImage64_load(struct kimage *image, char *kernel,
                kbuf.bufsz = kbuf.memsz = initrd_len;
                kbuf.buf_align = PAGE_SIZE;
                kbuf.buf_min = MIN_INITRD_LOAD_ADDR;
+               kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
                ret = kexec_add_buffer(&kbuf);
                if (ret)
                        goto out_free_params;