| Message ID | 20181017102012.872-6-fanc.fnst@cn.fujitsu.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
| Series | x86/boot/KASLR: Parse ACPI table and limit kaslr in immovable memory | expand |
On 10/17/18 at 06:20pm, Chao Fan wrote: > If KEXEC write the RSDP pointer to cmdline, parse the cmdline > and use it. > Imitate from early_param of "acpi_rsdp". > > Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com> > --- > arch/x86/boot/compressed/acpitb.c | 23 +++++++++++++++++++++++ > 1 file changed, 23 insertions(+) > > diff --git a/arch/x86/boot/compressed/acpitb.c b/arch/x86/boot/compressed/acpitb.c > index 50fa65cf824d..37b1f4407be8 100644 > --- a/arch/x86/boot/compressed/acpitb.c > +++ b/arch/x86/boot/compressed/acpitb.c > @@ -8,6 +8,9 @@ > #include <linux/numa.h> > #include <linux/acpi.h> > > +#define STATIC > +#include <linux/decompress/mm.h> > + > /* Search EFI table for RSDP table. */ > static void efi_get_rsdp_addr(acpi_physical_address *rsdp_addr) > { > @@ -200,3 +203,23 @@ static void bios_get_rsdp_addr(acpi_physical_address *rsdp_addr) > *rsdp_addr = (acpi_physical_address)address; > } > } > + > +static void get_acpi_rsdp(acpi_physical_address *rsdp_addr) > +{ > +#ifdef CONFIG_KEXEC > + unsigned long long res; > + int len = 0; > + char *val; > + > + val = malloc(20); Why is the length 20? Defined a macro? > + len = cmdline_find_option("acpi_rsdp", val, 20); > + > + if (len == -1) > + return; > + > + if (len > 0) { > + val[len] = 0; > + *rsdp_addr = (acpi_physical_address)kstrtoull(val, 0, &res); > + } > +#endif > +} > -- > 2.17.2 > > >
On Sun, Oct 21, 2018 at 10:26:50AM +0800, Baoquan He wrote: >On 10/17/18 at 06:20pm, Chao Fan wrote: >> If KEXEC write the RSDP pointer to cmdline, parse the cmdline >> and use it. >> Imitate from early_param of "acpi_rsdp". >> >> Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com> >> --- >> arch/x86/boot/compressed/acpitb.c | 23 +++++++++++++++++++++++ >> 1 file changed, 23 insertions(+) >> >> diff --git a/arch/x86/boot/compressed/acpitb.c b/arch/x86/boot/compressed/acpitb.c >> index 50fa65cf824d..37b1f4407be8 100644 >> --- a/arch/x86/boot/compressed/acpitb.c >> +++ b/arch/x86/boot/compressed/acpitb.c >> @@ -8,6 +8,9 @@ >> #include <linux/numa.h> >> #include <linux/acpi.h> >> >> +#define STATIC >> +#include <linux/decompress/mm.h> >> + >> /* Search EFI table for RSDP table. */ >> static void efi_get_rsdp_addr(acpi_physical_address *rsdp_addr) >> { >> @@ -200,3 +203,23 @@ static void bios_get_rsdp_addr(acpi_physical_address *rsdp_addr) >> *rsdp_addr = (acpi_physical_address)address; >> } >> } >> + >> +static void get_acpi_rsdp(acpi_physical_address *rsdp_addr) >> +{ >> +#ifdef CONFIG_KEXEC >> + unsigned long long res; >> + int len = 0; >> + char *val; >> + >> + val = malloc(20); > >Why is the length 20? Defined a macro? > Not a calculation, if it's enough to store the address, that will be OK. Thanks, Chao Fan >> + len = cmdline_find_option("acpi_rsdp", val, 20); >> + >> + if (len == -1) >> + return; >> + >> + if (len > 0) { >> + val[len] = 0; >> + *rsdp_addr = (acpi_physical_address)kstrtoull(val, 0, &res); >> + } >> +#endif >> +} >> -- >> 2.17.2 >> >> >> > >
On 10/22/18 at 05:30am, Fan, Chao wrote: > >> +static void get_acpi_rsdp(acpi_physical_address *rsdp_addr) > >> +{ > >> +#ifdef CONFIG_KEXEC > >> + unsigned long long res; > >> + int len = 0; > >> + char *val; > >> + > >> + val = malloc(20); > > > >Why is the length 20? Defined a macro? > > > > Not a calculation, if it's enough to store the address, that will be OK. Sorry, I didn't catch. It's 16 in setup_acpi_rsdp() of drivers/acpi/osl.c . What does 'that' mean? Wondering why not making it 200, it's also enough to store the address.
On Mon, Oct 22, 2018 at 02:06:13PM +0800, Baoquan He wrote: >On 10/22/18 at 05:30am, Fan, Chao wrote: >> >> +static void get_acpi_rsdp(acpi_physical_address *rsdp_addr) >> >> +{ >> >> +#ifdef CONFIG_KEXEC >> >> + unsigned long long res; >> >> + int len = 0; >> >> + char *val; >> >> + >> >> + val = malloc(20); >> > >> >Why is the length 20? Defined a macro? >> > >> >> Not a calculation, if it's enough to store the address, that will be OK. > >Sorry, I didn't catch. It's 16 in setup_acpi_rsdp() of >drivers/acpi/osl.c . What does 'that' mean? The second parameter of kstrtoull(), the 16 you mentioned means hexadecimal, not the length. I checked my host and guest, the value are ACPI20=0xbfbfa014, ACPI20=0xdb807000. The length of memory is 8. Well the max memory address is 16, add "0x" and '\0' is 19. So I set it as 20. I am not sure whether 8 is enough for the address, if OK, 11 will be enough, or 19 is OK. If my understanding is wrong, please tell me. Thanks, Chao Fan > >Wondering why not making it 200, it's also enough to store the address. > >
On 10/22/18 at 03:30pm, Chao Fan wrote: > On Mon, Oct 22, 2018 at 02:06:13PM +0800, Baoquan He wrote: > >On 10/22/18 at 05:30am, Fan, Chao wrote: > >> >> +static void get_acpi_rsdp(acpi_physical_address *rsdp_addr) > >> >> +{ > >> >> +#ifdef CONFIG_KEXEC > >> >> + unsigned long long res; > >> >> + int len = 0; > >> >> + char *val; > >> >> + > >> >> + val = malloc(20); > >> > > >> >Why is the length 20? Defined a macro? > >> > > >> > >> Not a calculation, if it's enough to store the address, that will be OK. > > > >Sorry, I didn't catch. It's 16 in setup_acpi_rsdp() of > >drivers/acpi/osl.c . What does 'that' mean? > > The second parameter of kstrtoull(), the 16 you mentioned means > hexadecimal, not the length. Yes, you are right. > I checked my host and guest, the value are ACPI20=0xbfbfa014, ACPI20=0xdb807000. > The length of memory is 8. Well the max memory address is 16, add > "0x" and '\0' is 19. So I set it as 20. > I am not sure whether 8 is enough for the address, if OK, 11 will > be enough, or 19 is OK. I am fine with 20. Thanks.
diff --git a/arch/x86/boot/compressed/acpitb.c b/arch/x86/boot/compressed/acpitb.c index 50fa65cf824d..37b1f4407be8 100644 --- a/arch/x86/boot/compressed/acpitb.c +++ b/arch/x86/boot/compressed/acpitb.c @@ -8,6 +8,9 @@ #include <linux/numa.h> #include <linux/acpi.h> +#define STATIC +#include <linux/decompress/mm.h> + /* Search EFI table for RSDP table. */ static void efi_get_rsdp_addr(acpi_physical_address *rsdp_addr) { @@ -200,3 +203,23 @@ static void bios_get_rsdp_addr(acpi_physical_address *rsdp_addr) *rsdp_addr = (acpi_physical_address)address; } } + +static void get_acpi_rsdp(acpi_physical_address *rsdp_addr) +{ +#ifdef CONFIG_KEXEC + unsigned long long res; + int len = 0; + char *val; + + val = malloc(20); + len = cmdline_find_option("acpi_rsdp", val, 20); + + if (len == -1) + return; + + if (len > 0) { + val[len] = 0; + *rsdp_addr = (acpi_physical_address)kstrtoull(val, 0, &res); + } +#endif +}
If KEXEC write the RSDP pointer to cmdline, parse the cmdline and use it. Imitate from early_param of "acpi_rsdp". Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com> --- arch/x86/boot/compressed/acpitb.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+)