On Thu, Nov 29, 2018 at 04:16:27PM +0800, Chao Fan wrote:
> To fix the conflict between KASLR and memory-hotremove, memory
> information in SRAT table is necessary.
>
> ACPI SRAT (System/Static Resource Affinity Table) can show the details
> about memory ranges, including ranges of memory provided by hot-added
> memory devices. SRAT table must be introduced by RSDP pointer (Root
> System Description Pointer). So RSDP should be found firstly.
>
> When booting form KEXEC/EFI/BIOS, the methods to find RSDP pointer
> are different. When booting from KEXEC, 'acpi_rsdp' may have been
> added to cmdline, so parse the cmdline and find the RSDP pointer.
>
> Signed-off-by: Chao Fan <fanc.f...@cn.fujitsu.com>
> ---
> arch/x86/boot/compressed/acpitb.c | 33 +++++++++++++++++++++++++++++++
> arch/x86/boot/compressed/misc.c | 5 +++++
> arch/x86/boot/compressed/misc.h | 4 ++++
> lib/kstrtox.c | 5 +++++
> 4 files changed, 47 insertions(+)
> create mode 100644 arch/x86/boot/compressed/acpitb.c
>
> diff --git a/arch/x86/boot/compressed/acpitb.c
> b/arch/x86/boot/compressed/acpitb.c
> new file mode 100644
> index 000000000000..614c45655cff
> --- /dev/null
> +++ b/arch/x86/boot/compressed/acpitb.c
> @@ -0,0 +1,33 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#define BOOT_CTYPE_H
> +#include "misc.h"
> +#include "error.h"
> +
> +#include <linux/efi.h>
> +#include <asm/efi.h>
> +#include <linux/numa.h>
> +#include <linux/acpi.h>
> +
> +#define STATIC
> +#include <linux/decompress/mm.h>
> +
> +/* Store the immovable memory regions. */
> +struct mem_vector immovable_mem[MAX_NUMNODES*2];
> +#endif
> +
> +static acpi_physical_address get_acpi_rsdp(void)
> +{
> +#ifdef CONFIG_KEXEC
> + unsigned long long res;
> + int len = 0;
> + char *val;
> +
> + val = malloc(19);
> + len = cmdline_find_option("acpi_rsdp", val, 19);
> + if (len > 0) {
> + val[len] = 0;
> + return (acpi_physical_address)kstrtoull(val, 16, &res);
> + }
> + return 0;
> +#endif
> +}
> diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
> index 8dd1d5ccae58..e51713fe3add 100644
> --- a/arch/x86/boot/compressed/misc.c
> +++ b/arch/x86/boot/compressed/misc.c
> @@ -12,6 +12,7 @@
> * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996
> */
>
> +#define BOOT_CTYPE_H
> #include "misc.h"
> #include "error.h"
> #include "pgtable.h"
> @@ -426,3 +427,7 @@ void fortify_panic(const char *name)
> {
> error("detected buffer overflow");
> }
> +
> +#ifdef BOOT_STRING
> +#include "../../../../lib/kstrtox.c"
> +#endif
> diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h
> index a1d5918765f3..809c31effa4b 100644
> --- a/arch/x86/boot/compressed/misc.h
> +++ b/arch/x86/boot/compressed/misc.h
> @@ -116,3 +116,7 @@ static inline void console_init(void)
> void set_sev_encryption_mask(void);
>
> #endif
> +
> +/* acpitb.c */
> +#define BOOT_STRING
> +extern int kstrtoull(const char *s, unsigned int base, unsigned long long
> *res);
> diff --git a/lib/kstrtox.c b/lib/kstrtox.c
> index 1006bf70bf74..a0ac1b2257b8 100644
> --- a/lib/kstrtox.c
> +++ b/lib/kstrtox.c
> @@ -126,6 +126,9 @@ int kstrtoull(const char *s, unsigned int base, unsigned
> long long *res)
> }
> EXPORT_SYMBOL(kstrtoull);
>
> +/* Make compressed period code be able to use kstrtoull(). */
> +#ifndef BOOT_STRING
I got the following build error.
]$ make arch/x86/boot/compressed/misc.o
CALL scripts/checksyscalls.sh
DESCEND objtool
CC arch/x86/boot/compressed/misc.o
ld: -r and -pie may not be used together
make[1]: *** [scripts/Makefile.build:294: arch/x86/boot/compressed/misc.o]
Error 1
make: *** [Makefile:1715: arch/x86/boot/compressed/misc.o] Error 2
]$
I think this error gets fixed by changing the BOOT_STRING ifndef
order before the EXPORT_SYMBOL, like this:
#ifndef BOOT_STRING
EXPORT_SYMBOL(kstrtoull);
I'm not sure this change is a good way...
Thanks,
Masa
