* [PATCH] x86/boot: Move detecting acpi=off in cmdline to get_rsdp_addr()
@ 2019-02-15 9:10 Chao Fan
2019-02-15 9:28 ` Borislav Petkov
0 siblings, 1 reply; 3+ messages in thread
From: Chao Fan @ 2019-02-15 9:10 UTC (permalink / raw)
To: linux-kernel, tglx, mingo, hpa, x86, bp
If "acpi=off" specified in cmdline, the whole functions of acpi.c
should not work, there is no need to ealy parse RSDP, so detect
"acpi=off" in the very first place.
Also replace magic number with macro.
Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
---
arch/x86/boot/compressed/acpi.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/arch/x86/boot/compressed/acpi.c b/arch/x86/boot/compressed/acpi.c
index 0ef4ad55b29b..5510a2105b7b 100644
--- a/arch/x86/boot/compressed/acpi.c
+++ b/arch/x86/boot/compressed/acpi.c
@@ -213,8 +213,13 @@ static acpi_physical_address bios_get_rsdp_addr(void)
/* Return RSDP address on success, otherwise 0. */
acpi_physical_address get_rsdp_addr(void)
{
+ char arg[MAX_ACPI_ARG_LENGTH];
acpi_physical_address pa;
+ if (cmdline_find_option("acpi", arg, sizeof(arg)) == 3 &&
+ !strncmp(arg, "off", 3))
+ return 0;
+
pa = get_acpi_rsdp();
if (!pa)
@@ -235,9 +240,9 @@ static unsigned long get_acpi_srat_table(void)
{
unsigned long root_table, acpi_table;
struct acpi_table_header *header;
+ char arg[MAX_ACPI_ARG_LENGTH];
struct acpi_table_rsdp *rsdp;
u32 num_entries, size, len;
- char arg[10];
u8 *entry;
rsdp = (struct acpi_table_rsdp *)(long)boot_params->acpi_rsdp_addr;
@@ -299,13 +304,8 @@ int count_immovable_mem_regions(void)
unsigned long table_addr, table_end, table;
struct acpi_subtable_header *sub_table;
struct acpi_table_header *table_header;
- char arg[MAX_ACPI_ARG_LENGTH];
int num = 0;
- if (cmdline_find_option("acpi", arg, sizeof(arg)) == 3 &&
- !strncmp(arg, "off", 3))
- return 0;
-
table_addr = get_acpi_srat_table();
if (!table_addr)
return 0;
--
2.20.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] x86/boot: Move detecting acpi=off in cmdline to get_rsdp_addr()
2019-02-15 9:10 [PATCH] x86/boot: Move detecting acpi=off in cmdline to get_rsdp_addr() Chao Fan
@ 2019-02-15 9:28 ` Borislav Petkov
2019-02-15 9:46 ` Chao Fan
0 siblings, 1 reply; 3+ messages in thread
From: Borislav Petkov @ 2019-02-15 9:28 UTC (permalink / raw)
To: Chao Fan; +Cc: linux-kernel, tglx, mingo, hpa, x86
On Fri, Feb 15, 2019 at 05:10:47PM +0800, Chao Fan wrote:
> If "acpi=off" specified in cmdline, the whole functions of acpi.c
> should not work, there is no need to ealy parse RSDP, so detect
> "acpi=off" in the very first place.
>
> Also replace magic number with macro.
>
> Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
> ---
> arch/x86/boot/compressed/acpi.c | 12 ++++++------
> 1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/boot/compressed/acpi.c b/arch/x86/boot/compressed/acpi.c
> index 0ef4ad55b29b..5510a2105b7b 100644
> --- a/arch/x86/boot/compressed/acpi.c
> +++ b/arch/x86/boot/compressed/acpi.c
> @@ -213,8 +213,13 @@ static acpi_physical_address bios_get_rsdp_addr(void)
> /* Return RSDP address on success, otherwise 0. */
> acpi_physical_address get_rsdp_addr(void)
> {
> + char arg[MAX_ACPI_ARG_LENGTH];
> acpi_physical_address pa;
>
> + if (cmdline_find_option("acpi", arg, sizeof(arg)) == 3 &&
> + !strncmp(arg, "off", 3))
> + return 0;
This place looks wrong because we have a get_acpi_rsdp() call before
that which overrides acpi=off practically.
Also, if you move it to get_rsdp_addr(), add a static variable recording
the previous result of the cmdline parsing because I don't want it
parsing cmdline each time it is called.
Thx.
--
Regards/Gruss,
Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] x86/boot: Move detecting acpi=off in cmdline to get_rsdp_addr()
2019-02-15 9:28 ` Borislav Petkov
@ 2019-02-15 9:46 ` Chao Fan
0 siblings, 0 replies; 3+ messages in thread
From: Chao Fan @ 2019-02-15 9:46 UTC (permalink / raw)
To: Borislav Petkov; +Cc: linux-kernel, tglx, mingo, hpa, x86
On Fri, Feb 15, 2019 at 10:28:41AM +0100, Borislav Petkov wrote:
>On Fri, Feb 15, 2019 at 05:10:47PM +0800, Chao Fan wrote:
>> If "acpi=off" specified in cmdline, the whole functions of acpi.c
>> should not work, there is no need to ealy parse RSDP, so detect
>> "acpi=off" in the very first place.
>>
>> Also replace magic number with macro.
>>
>> Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
>> ---
>> arch/x86/boot/compressed/acpi.c | 12 ++++++------
>> 1 file changed, 6 insertions(+), 6 deletions(-)
>>
>> diff --git a/arch/x86/boot/compressed/acpi.c b/arch/x86/boot/compressed/acpi.c
>> index 0ef4ad55b29b..5510a2105b7b 100644
>> --- a/arch/x86/boot/compressed/acpi.c
>> +++ b/arch/x86/boot/compressed/acpi.c
>> @@ -213,8 +213,13 @@ static acpi_physical_address bios_get_rsdp_addr(void)
>> /* Return RSDP address on success, otherwise 0. */
>> acpi_physical_address get_rsdp_addr(void)
>> {
>> + char arg[MAX_ACPI_ARG_LENGTH];
>> acpi_physical_address pa;
>>
>> + if (cmdline_find_option("acpi", arg, sizeof(arg)) == 3 &&
>> + !strncmp(arg, "off", 3))
>> + return 0;
>
>This place looks wrong because we have a get_acpi_rsdp() call before
>that which overrides acpi=off practically.
Oh thanks.
In my old version PATCH, it was in count_immovable_mem_regions() which
is the entry function of acpi.c. Then in last version, I splite acpi.c
so that the first entry is get_rsdp_addr(), that's why I want to move
the detecting here.
>
>Also, if you move it to get_rsdp_addr(), add a static variable recording
>the previous result of the cmdline parsing because I don't want it
>parsing cmdline each time it is called.
Thanks,
Chao Fan
>
>Thx.
>
>--
>Regards/Gruss,
> Boris.
>
>Good mailing practices for 400: avoid top-posting and trim the reply.
>
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2019-02-15 9:10 [PATCH] x86/boot: Move detecting acpi=off in cmdline to get_rsdp_addr() Chao Fan
2019-02-15 9:28 ` Borislav Petkov
2019-02-15 9:46 ` Chao Fan
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