* [PATCH v4] efi: arm64: Add vmlinux debug link to the Image binary
@ 2017-02-02 17:33 Ard Biesheuvel
2017-02-02 18:30 ` Will Deacon
0 siblings, 1 reply; 6+ messages in thread
From: Ard Biesheuvel @ 2017-02-02 17:33 UTC (permalink / raw)
To: linux-arm-kernel
When building with debugging symbols, take the absolute path to the
vmlinux binary and add it to the special PE/COFF debug table entry.
This allows a debug EFI build to find the vmlinux binary, which is
very helpful in debugging, given that the offset where the Image is
first loaded by EFI is highly unpredictable.
On implementations of UEFI that choose to implement it, this
information is exposed via the EFI debug support table, which is a UEFI
configuration table that is accessible both by the firmware at boot time
and by the OS at runtime, and lists all PE/COFF images loaded by the
system.
The format of the NB10 Codeview entry is based on the definition used
by EDK2, which is our primary reference when it comes to the use of
PE/COFF in the context of UEFI firmware.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
v4: add a separate DEBUG_EFI debug option so that this feature is disabled
by default
dropped 1/2 which has been queued already in the EFI tree
use ASCII rather than an opaque constant for "NB10" signature
arch/arm64/Kconfig.debug | 8 ++++
arch/arm64/kernel/Makefile | 4 ++
arch/arm64/kernel/head.S | 47 +++++++++++++++++++-
3 files changed, 58 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/Kconfig.debug b/arch/arm64/Kconfig.debug
index d1ebd46872fd..f7f38b1aab14 100644
--- a/arch/arm64/Kconfig.debug
+++ b/arch/arm64/Kconfig.debug
@@ -95,6 +95,14 @@ config DEBUG_ALIGN_RODATA
If in doubt, say N.
+config DEBUG_EFI
+ depends on EFI && DEBUG_INFO
+ bool "UEFI debugging"
+ help
+ Enable this option to include EFI specific debugging features into
+ the kernel that are only useful when using a debug build of the
+ UEFI firmware
+
source "drivers/hwtracing/coresight/Kconfig"
endmenu
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index 7d66bbaafc0c..2600c60337ac 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -55,3 +55,7 @@ obj-y += $(arm64-obj-y) vdso/ probes/
obj-m += $(arm64-obj-m)
head-y := head.o
extra-y += $(head-y) vmlinux.lds
+
+ifeq ($(CONFIG_DEBUG_EFI),y)
+AFLAGS_head.o += -DVMLINUX_PATH="\"$(shell readlink -f $(objtree)/vmlinux)\""
+endif
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 4b1abac3485a..d9faf09f6401 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -149,7 +149,7 @@ extra_header_fields:
.quad 0 // SizeOfHeapReserve
.quad 0 // SizeOfHeapCommit
.long 0 // LoaderFlags
- .long 0x6 // NumberOfRvaAndSizes
+ .long (section_table - .) / 8 // NumberOfRvaAndSizes
.quad 0 // ExportTable
.quad 0 // ImportTable
@@ -158,6 +158,11 @@ extra_header_fields:
.quad 0 // CertificationTable
.quad 0 // BaseRelocationTable
+#ifdef CONFIG_DEBUG_EFI
+ .long efi_debug_table - _head // DebugTable
+ .long efi_debug_table_size
+#endif
+
// Section table
section_table:
@@ -195,6 +200,46 @@ section_table:
.short 0 // NumberOfLineNumbers (0 for executables)
.long 0xe0500020 // Characteristics (section flags)
+#ifdef CONFIG_DEBUG_EFI
+ /*
+ * The debug table is referenced via its Relative Virtual Address (RVA),
+ * which is only defined for those parts of the image that are covered
+ * by a section declaration. Since this header is not covered by any
+ * section, the debug table must be emitted elsewhere. So stick it in
+ * the .init.rodata section instead.
+ *
+ * Note that the EFI debug entry itself may legally have a zero RVA,
+ * which means we can simply put it right after the section headers.
+ */
+ __INITRODATA
+
+ .align 2
+efi_debug_table:
+ // EFI_IMAGE_DEBUG_DIRECTORY_ENTRY
+ .long 0 // Characteristics
+ .long 0 // TimeDateStamp
+ .short 0 // MajorVersion
+ .short 0 // MinorVersion
+ .long 2 // Type == EFI_IMAGE_DEBUG_TYPE_CODEVIEW
+ .long efi_debug_entry_size // SizeOfData
+ .long 0 // RVA
+ .long efi_debug_entry - _head // FileOffset
+
+ .set efi_debug_table_size, . - efi_debug_table
+ .previous
+
+efi_debug_entry:
+ // EFI_IMAGE_DEBUG_CODEVIEW_NB10_ENTRY
+ .ascii "NB10" // Signature
+ .long 0 // Unknown
+ .long 0 // Unknown2
+ .long 0 // Unknown3
+
+ .asciz VMLINUX_PATH
+
+ .set efi_debug_entry_size, . - efi_debug_entry
+#endif
+
/*
* EFI will load .text onwards at the 4k section alignment
* described in the PE/COFF header. To ensure that instruction
--
2.7.4
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v4] efi: arm64: Add vmlinux debug link to the Image binary
2017-02-02 17:33 [PATCH v4] efi: arm64: Add vmlinux debug link to the Image binary Ard Biesheuvel
@ 2017-02-02 18:30 ` Will Deacon
2017-02-02 18:36 ` Ard Biesheuvel
0 siblings, 1 reply; 6+ messages in thread
From: Will Deacon @ 2017-02-02 18:30 UTC (permalink / raw)
To: linux-arm-kernel
Hi Ard,
On Thu, Feb 02, 2017 at 05:33:19PM +0000, Ard Biesheuvel wrote:
> When building with debugging symbols, take the absolute path to the
> vmlinux binary and add it to the special PE/COFF debug table entry.
> This allows a debug EFI build to find the vmlinux binary, which is
> very helpful in debugging, given that the offset where the Image is
> first loaded by EFI is highly unpredictable.
>
> On implementations of UEFI that choose to implement it, this
> information is exposed via the EFI debug support table, which is a UEFI
> configuration table that is accessible both by the firmware at boot time
> and by the OS at runtime, and lists all PE/COFF images loaded by the
> system.
>
> The format of the NB10 Codeview entry is based on the definition used
> by EDK2, which is our primary reference when it comes to the use of
> PE/COFF in the context of UEFI firmware.
>
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> ---
> v4: add a separate DEBUG_EFI debug option so that this feature is disabled
> by default
> dropped 1/2 which has been queued already in the EFI tree
> use ASCII rather than an opaque constant for "NB10" signature
>
> arch/arm64/Kconfig.debug | 8 ++++
> arch/arm64/kernel/Makefile | 4 ++
> arch/arm64/kernel/head.S | 47 +++++++++++++++++++-
> 3 files changed, 58 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm64/Kconfig.debug b/arch/arm64/Kconfig.debug
> index d1ebd46872fd..f7f38b1aab14 100644
> --- a/arch/arm64/Kconfig.debug
> +++ b/arch/arm64/Kconfig.debug
> @@ -95,6 +95,14 @@ config DEBUG_ALIGN_RODATA
>
> If in doubt, say N.
>
> +config DEBUG_EFI
> + depends on EFI && DEBUG_INFO
> + bool "UEFI debugging"
> + help
> + Enable this option to include EFI specific debugging features into
> + the kernel that are only useful when using a debug build of the
> + UEFI firmware
> +
I don't much like embedding the absolute host build path in the kernel
image, but if that's what the tools expect then so be it.
> source "drivers/hwtracing/coresight/Kconfig"
>
> endmenu
> diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
> index 7d66bbaafc0c..2600c60337ac 100644
> --- a/arch/arm64/kernel/Makefile
> +++ b/arch/arm64/kernel/Makefile
> @@ -55,3 +55,7 @@ obj-y += $(arm64-obj-y) vdso/ probes/
> obj-m += $(arm64-obj-m)
> head-y := head.o
> extra-y += $(head-y) vmlinux.lds
> +
> +ifeq ($(CONFIG_DEBUG_EFI),y)
> +AFLAGS_head.o += -DVMLINUX_PATH="\"$(shell readlink -f $(objtree)/vmlinux)\""
> +endif
Can we use the Make realpath directive instead of calling out to the shell?
Do you want me to merge this via arm64?
Will
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v4] efi: arm64: Add vmlinux debug link to the Image binary
2017-02-02 18:30 ` Will Deacon
@ 2017-02-02 18:36 ` Ard Biesheuvel
2017-02-03 14:50 ` Ard Biesheuvel
0 siblings, 1 reply; 6+ messages in thread
From: Ard Biesheuvel @ 2017-02-02 18:36 UTC (permalink / raw)
To: linux-arm-kernel
On 2 February 2017 at 18:30, Will Deacon <will.deacon@arm.com> wrote:
> Hi Ard,
>
> On Thu, Feb 02, 2017 at 05:33:19PM +0000, Ard Biesheuvel wrote:
>> When building with debugging symbols, take the absolute path to the
>> vmlinux binary and add it to the special PE/COFF debug table entry.
>> This allows a debug EFI build to find the vmlinux binary, which is
>> very helpful in debugging, given that the offset where the Image is
>> first loaded by EFI is highly unpredictable.
>>
>> On implementations of UEFI that choose to implement it, this
>> information is exposed via the EFI debug support table, which is a UEFI
>> configuration table that is accessible both by the firmware at boot time
>> and by the OS at runtime, and lists all PE/COFF images loaded by the
>> system.
>>
>> The format of the NB10 Codeview entry is based on the definition used
>> by EDK2, which is our primary reference when it comes to the use of
>> PE/COFF in the context of UEFI firmware.
>>
>> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
>> ---
>> v4: add a separate DEBUG_EFI debug option so that this feature is disabled
>> by default
>> dropped 1/2 which has been queued already in the EFI tree
>> use ASCII rather than an opaque constant for "NB10" signature
>>
>> arch/arm64/Kconfig.debug | 8 ++++
>> arch/arm64/kernel/Makefile | 4 ++
>> arch/arm64/kernel/head.S | 47 +++++++++++++++++++-
>> 3 files changed, 58 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm64/Kconfig.debug b/arch/arm64/Kconfig.debug
>> index d1ebd46872fd..f7f38b1aab14 100644
>> --- a/arch/arm64/Kconfig.debug
>> +++ b/arch/arm64/Kconfig.debug
>> @@ -95,6 +95,14 @@ config DEBUG_ALIGN_RODATA
>>
>> If in doubt, say N.
>>
>> +config DEBUG_EFI
>> + depends on EFI && DEBUG_INFO
>> + bool "UEFI debugging"
>> + help
>> + Enable this option to include EFI specific debugging features into
>> + the kernel that are only useful when using a debug build of the
>> + UEFI firmware
>> +
>
> I don't much like embedding the absolute host build path in the kernel
> image, but if that's what the tools expect then so be it.
>
>> source "drivers/hwtracing/coresight/Kconfig"
>>
>> endmenu
>> diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
>> index 7d66bbaafc0c..2600c60337ac 100644
>> --- a/arch/arm64/kernel/Makefile
>> +++ b/arch/arm64/kernel/Makefile
>> @@ -55,3 +55,7 @@ obj-y += $(arm64-obj-y) vdso/ probes/
>> obj-m += $(arm64-obj-m)
>> head-y := head.o
>> extra-y += $(head-y) vmlinux.lds
>> +
>> +ifeq ($(CONFIG_DEBUG_EFI),y)
>> +AFLAGS_head.o += -DVMLINUX_PATH="\"$(shell readlink -f $(objtree)/vmlinux)\""
>> +endif
>
> Can we use the Make realpath directive instead of calling out to the shell?
>
Yep. This works as expected:
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index 2600c60337ac..1606c6b2a280 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -57,5 +57,5 @@ head-y := head.o
extra-y += $(head-y) vmlinux.lds
ifeq ($(CONFIG_DEBUG_EFI),y)
-AFLAGS_head.o += -DVMLINUX_PATH="\"$(shell readlink -f $(objtree)/vmlinux)\""
+AFLAGS_head.o += -DVMLINUX_PATH="\"$(realpath $(objtree)/vmlinux)\""
endif
> Do you want me to merge this via arm64?
>
Yes, please
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v4] efi: arm64: Add vmlinux debug link to the Image binary
2017-02-02 18:36 ` Ard Biesheuvel
@ 2017-02-03 14:50 ` Ard Biesheuvel
2017-02-03 15:17 ` Will Deacon
0 siblings, 1 reply; 6+ messages in thread
From: Ard Biesheuvel @ 2017-02-03 14:50 UTC (permalink / raw)
To: linux-arm-kernel
On 2 February 2017 at 18:36, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote:
> On 2 February 2017 at 18:30, Will Deacon <will.deacon@arm.com> wrote:
>> Hi Ard,
>>
>> On Thu, Feb 02, 2017 at 05:33:19PM +0000, Ard Biesheuvel wrote:
>>> When building with debugging symbols, take the absolute path to the
>>> vmlinux binary and add it to the special PE/COFF debug table entry.
>>> This allows a debug EFI build to find the vmlinux binary, which is
>>> very helpful in debugging, given that the offset where the Image is
>>> first loaded by EFI is highly unpredictable.
>>>
>>> On implementations of UEFI that choose to implement it, this
>>> information is exposed via the EFI debug support table, which is a UEFI
>>> configuration table that is accessible both by the firmware at boot time
>>> and by the OS at runtime, and lists all PE/COFF images loaded by the
>>> system.
>>>
>>> The format of the NB10 Codeview entry is based on the definition used
>>> by EDK2, which is our primary reference when it comes to the use of
>>> PE/COFF in the context of UEFI firmware.
>>>
>>> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
>>> ---
>>> v4: add a separate DEBUG_EFI debug option so that this feature is disabled
>>> by default
>>> dropped 1/2 which has been queued already in the EFI tree
>>> use ASCII rather than an opaque constant for "NB10" signature
>>>
>>> arch/arm64/Kconfig.debug | 8 ++++
>>> arch/arm64/kernel/Makefile | 4 ++
>>> arch/arm64/kernel/head.S | 47 +++++++++++++++++++-
>>> 3 files changed, 58 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/arch/arm64/Kconfig.debug b/arch/arm64/Kconfig.debug
>>> index d1ebd46872fd..f7f38b1aab14 100644
>>> --- a/arch/arm64/Kconfig.debug
>>> +++ b/arch/arm64/Kconfig.debug
>>> @@ -95,6 +95,14 @@ config DEBUG_ALIGN_RODATA
>>>
>>> If in doubt, say N.
>>>
>>> +config DEBUG_EFI
>>> + depends on EFI && DEBUG_INFO
>>> + bool "UEFI debugging"
>>> + help
>>> + Enable this option to include EFI specific debugging features into
>>> + the kernel that are only useful when using a debug build of the
>>> + UEFI firmware
>>> +
>>
>> I don't much like embedding the absolute host build path in the kernel
>> image, but if that's what the tools expect then so be it.
>>
>>> source "drivers/hwtracing/coresight/Kconfig"
>>>
>>> endmenu
>>> diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
>>> index 7d66bbaafc0c..2600c60337ac 100644
>>> --- a/arch/arm64/kernel/Makefile
>>> +++ b/arch/arm64/kernel/Makefile
>>> @@ -55,3 +55,7 @@ obj-y += $(arm64-obj-y) vdso/ probes/
>>> obj-m += $(arm64-obj-m)
>>> head-y := head.o
>>> extra-y += $(head-y) vmlinux.lds
>>> +
>>> +ifeq ($(CONFIG_DEBUG_EFI),y)
>>> +AFLAGS_head.o += -DVMLINUX_PATH="\"$(shell readlink -f $(objtree)/vmlinux)\""
>>> +endif
>>
>> Can we use the Make realpath directive instead of calling out to the shell?
>>
>
> Yep. This works as expected:
>
> diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
> index 2600c60337ac..1606c6b2a280 100644
> --- a/arch/arm64/kernel/Makefile
> +++ b/arch/arm64/kernel/Makefile
> @@ -57,5 +57,5 @@ head-y := head.o
> extra-y += $(head-y) vmlinux.lds
>
> ifeq ($(CONFIG_DEBUG_EFI),y)
> -AFLAGS_head.o += -DVMLINUX_PATH="\"$(shell readlink -f $(objtree)/vmlinux)\""
> +AFLAGS_head.o += -DVMLINUX_PATH="\"$(realpath $(objtree)/vmlinux)\""
> endif
>
>
>> Do you want me to merge this via arm64?
>>
>
> Yes, please
Should I respin this?
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v4] efi: arm64: Add vmlinux debug link to the Image binary
2017-02-03 14:50 ` Ard Biesheuvel
@ 2017-02-03 15:17 ` Will Deacon
2017-02-03 15:20 ` Ard Biesheuvel
0 siblings, 1 reply; 6+ messages in thread
From: Will Deacon @ 2017-02-03 15:17 UTC (permalink / raw)
To: linux-arm-kernel
On Fri, Feb 03, 2017 at 02:50:40PM +0000, Ard Biesheuvel wrote:
> On 2 February 2017 at 18:36, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote:
> > On 2 February 2017 at 18:30, Will Deacon <will.deacon@arm.com> wrote:
> >> On Thu, Feb 02, 2017 at 05:33:19PM +0000, Ard Biesheuvel wrote:
> > diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
> > index 2600c60337ac..1606c6b2a280 100644
> > --- a/arch/arm64/kernel/Makefile
> > +++ b/arch/arm64/kernel/Makefile
> > @@ -57,5 +57,5 @@ head-y := head.o
> > extra-y += $(head-y) vmlinux.lds
> >
> > ifeq ($(CONFIG_DEBUG_EFI),y)
> > -AFLAGS_head.o += -DVMLINUX_PATH="\"$(shell readlink -f $(objtree)/vmlinux)\""
> > +AFLAGS_head.o += -DVMLINUX_PATH="\"$(realpath $(objtree)/vmlinux)\""
> > endif
> >
> >
> >> Do you want me to merge this via arm64?
> >>
> >
> > Yes, please
>
> Should I respin this?
No need, I'll pick it up and make the change. I'll push out before I leave
work this evening.
Will
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v4] efi: arm64: Add vmlinux debug link to the Image binary
2017-02-03 15:17 ` Will Deacon
@ 2017-02-03 15:20 ` Ard Biesheuvel
0 siblings, 0 replies; 6+ messages in thread
From: Ard Biesheuvel @ 2017-02-03 15:20 UTC (permalink / raw)
To: linux-arm-kernel
On 3 February 2017 at 15:17, Will Deacon <will.deacon@arm.com> wrote:
> On Fri, Feb 03, 2017 at 02:50:40PM +0000, Ard Biesheuvel wrote:
>> On 2 February 2017 at 18:36, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote:
>> > On 2 February 2017 at 18:30, Will Deacon <will.deacon@arm.com> wrote:
>> >> On Thu, Feb 02, 2017 at 05:33:19PM +0000, Ard Biesheuvel wrote:
>> > diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
>> > index 2600c60337ac..1606c6b2a280 100644
>> > --- a/arch/arm64/kernel/Makefile
>> > +++ b/arch/arm64/kernel/Makefile
>> > @@ -57,5 +57,5 @@ head-y := head.o
>> > extra-y += $(head-y) vmlinux.lds
>> >
>> > ifeq ($(CONFIG_DEBUG_EFI),y)
>> > -AFLAGS_head.o += -DVMLINUX_PATH="\"$(shell readlink -f $(objtree)/vmlinux)\""
>> > +AFLAGS_head.o += -DVMLINUX_PATH="\"$(realpath $(objtree)/vmlinux)\""
>> > endif
>> >
>> >
>> >> Do you want me to merge this via arm64?
>> >>
>> >
>> > Yes, please
>>
>> Should I respin this?
>
> No need, I'll pick it up and make the change. I'll push out before I leave
> work this evening.
>
Cheers
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2017-02-03 15:20 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2017-02-02 17:33 [PATCH v4] efi: arm64: Add vmlinux debug link to the Image binary Ard Biesheuvel
2017-02-02 18:30 ` Will Deacon
2017-02-02 18:36 ` Ard Biesheuvel
2017-02-03 14:50 ` Ard Biesheuvel
2017-02-03 15:17 ` Will Deacon
2017-02-03 15:20 ` Ard Biesheuvel
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox