Messages in this thread Patch in this message | | | Date | Thu, 29 Nov 2018 11:20:13 -0500 | From | Masayoshi Mizuma <> | Subject | Re: [PATCH v12 1/5] x86/boot: Add get_acpi_rsdp() to parse RSDP in cmdline from KEXEC |
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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.fnst@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;
val[len] = '\0';
> + return (acpi_physical_address)kstrtoull(val, 16, &res); > + }
I think free() is needed. Or why don't you use stack?
char val[19];
len = cmdline_find_option("acpi_rsdp", val, sizeof(val)); if (len > 0) { val[len] = '\0'; return (acpi_physical_address)kstrtoull(val, 16, &res); }
Thanks, Masa
> + 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 > + > /** > * kstrtoll - convert a string to a long long > * @s: The start of the string. The string must be null-terminated, and may also > @@ -408,3 +411,5 @@ kstrto_from_user(kstrtou16_from_user, kstrtou16, u16); > kstrto_from_user(kstrtos16_from_user, kstrtos16, s16); > kstrto_from_user(kstrtou8_from_user, kstrtou8, u8); > kstrto_from_user(kstrtos8_from_user, kstrtos8, s8); > + > +#endif /* BOOT_STRING */ > -- > 2.19.1 > > >
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