* [Buildroot] [PATCHv2] toolchain: granular choice for stack protector
@ 2015-12-26 23:42 Yann E. MORIN
2015-12-27 0:27 ` Steven Noonan
2015-12-27 10:19 ` Thomas Petazzoni
0 siblings, 2 replies; 7+ messages in thread
From: Yann E. MORIN @ 2015-12-26 23:42 UTC (permalink / raw)
To: buildroot
From: Steven Noonan <steven@uplinklabs.net>
Currently, we only support two levels of stach-smashing protection:
- entirely disabled,
- protect _all_ functions with -fstack-protector-all.
-fstack-protector-all tends to be far too aggressive and impacts
performance too much to be worth on a real product.
Add a choice that allows us to select between different levels of
stack-smashing protection:
- none
- basic (NEW)
- strong (NEW)
- all
The differences are documented in the GCC online documentation:
https://gcc.gnu.org/onlinedocs/gcc-4.9.2/gcc/Optimize-Options.html
Signed-off-by: Steven Noonan <steven@uplinklabs.net>
[yann.morin.1998 at free.fr:
- rebase
- add legacy handling
- SSP-strong depends on gcc >= 4.9
- slightly simple ifeq-block in package/Makefile.in
- keep the comment in the choice; add a comment shen strong is not
available
- update commit log
]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
---
Changes v1 -> v2:
- see commit log ;-) (Yann)
---
Note: I (Yann) have only slightly tested this patch. More testing is in
order before we can apply this. Steven, care to see if it still fits
your need? Thanks! :-)
---
Config.in | 50 +++++++++++++++++++++++++++++++++++++++++++++-----
Config.in.legacy | 8 ++++++++
package/Makefile.in | 8 +++++++-
3 files changed, 60 insertions(+), 6 deletions(-)
diff --git a/Config.in b/Config.in
index 0be44d9..1e85d78 100644
--- a/Config.in
+++ b/Config.in
@@ -522,12 +522,14 @@ config BR2_GOOGLE_BREAKPAD_INCLUDE_FILES
endif
-config BR2_ENABLE_SSP
+choice
bool "build code with Stack Smashing Protection"
- depends on BR2_TOOLCHAIN_HAS_SSP
+ default BR2_SSP_ALL if BR2_ENABLE_SSP # legacy
+ default BR2_SSP_STRONG if BR2_TOOLCHAIN_GCC_AT_LEAST_4_9
+ default BR2_SSP_REGULAR
help
- Enable stack smashing protection support using GCCs
- -fstack-protector-all option.
+ Enable stack smashing protection support using GCC's
+ -fstack-protector option family.
See http://www.linuxfromscratch.org/hints/downloads/files/ssp.txt
for details.
@@ -536,9 +538,47 @@ config BR2_ENABLE_SSP
support. This is always the case for glibc and eglibc
toolchain, but is optional in uClibc toolchains.
-comment "enabling Stack Smashing Protection requires support in the toolchain"
+config BR2_SSP_NONE
+ bool "None"
+ help
+ Disable stack-smashing protection.
+
+comment "Stack Smashing Protection needs a toolchain w/ SSP"
depends on !BR2_TOOLCHAIN_HAS_SSP
+config BR2_SSP_REGULAR
+ bool "-fstack-protector"
+ depends on BR2_TOOLCHAIN_HAS_SSP
+ help
+ Emit extra code to check for buffer overflows, such as stack
+ smashing attacks. This is done by adding a guard variable to
+ functions with vulnerable objects. This includes functions
+ that call alloca, and functions with buffers larger than 8
+ bytes. The guards are initialized when a function is entered
+ and then checked when the function exits. If a guard check
+ fails, an error message is printed and the program exits.
+
+config BR2_SSP_STRONG
+ bool "-fstack-protector-strong"
+ depends on BR2_TOOLCHAIN_HAS_SSP
+ depends on BR2_TOOLCHAIN_GCC_AT_LEAST_4_9
+ help
+ Like -fstack-protector but includes additional functions to be
+ protected - those that have local array definitions, or have
+ references to local frame addresses.
+
+comment "Stack Smashing Protection strong needs a toolchain w/ gcc >= 4.9"
+ depends on BR2_TOOLCHAIN_HAS_SSP
+ depends on !BR2_TOOLCHAIN_GCC_AT_LEAST_4_9
+
+config BR2_SSP_ALL
+ bool "-fstack-protector-all"
+ depends on BR2_TOOLCHAIN_HAS_SSP
+ help
+ Like -fstack-protector except that all functions are protected.
+
+endchoice
+
choice
bool "libraries"
default BR2_SHARED_LIBS if BR2_BINFMT_SUPPORTS_SHARED
diff --git a/Config.in.legacy b/Config.in.legacy
index 2628796..5d45d04 100644
--- a/Config.in.legacy
+++ b/Config.in.legacy
@@ -145,6 +145,14 @@ endif
###############################################################################
comment "Legacy options removed in 2016.02"
+# BR2_ENABLE_SSP is still referenced in Config.in (default in choice)
+config BR2_ENABLE_SSP
+ bool "Stack Smashing protection now has different levels"
+ help
+ The protection offered by SSP can now be selected from different
+ protection levels. Be sure to review the SSP level in the build
+ options menu.
+
config BR2_PACKAGE_DIRECTFB_CLE266
bool "cle266 driver for directfb removed"
select BR2_LEGACY
diff --git a/package/Makefile.in b/package/Makefile.in
index 82a66c2..c5652af 100644
--- a/package/Makefile.in
+++ b/package/Makefile.in
@@ -159,7 +159,13 @@ TARGET_CFLAGS += -msep-data
TARGET_CXXFLAGS += -msep-data
endif
-ifeq ($(BR2_ENABLE_SSP),y)
+ifeq ($(BR2_SSP_REGULAR),y)
+TARGET_CFLAGS += -fstack-protector
+TARGET_CXXFLAGS += -fstack-protector
+else ifeq ($(BR2_SSP_STRONG),y)
+TARGET_CFLAGS += -fstack-protector-strong
+TARGET_CXXFLAGS += -fstack-protector-strong
+else ifeq ($(BR2_SSP_ALL),y)
TARGET_CFLAGS += -fstack-protector-all
TARGET_CXXFLAGS += -fstack-protector-all
endif
--
1.9.1
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [Buildroot] [PATCHv2] toolchain: granular choice for stack protector
2015-12-26 23:42 [Buildroot] [PATCHv2] toolchain: granular choice for stack protector Yann E. MORIN
@ 2015-12-27 0:27 ` Steven Noonan
2015-12-27 9:23 ` Yann E. MORIN
2015-12-27 10:19 ` Thomas Petazzoni
1 sibling, 1 reply; 7+ messages in thread
From: Steven Noonan @ 2015-12-27 0:27 UTC (permalink / raw)
To: buildroot
LGTM. Also looks like a better implementation than what I've been
using (like the BR2_TOOLCHAIN_GCC_AT_LEAST_4_9 usage). The next time I
rebase my tree I'll include this version instead and see how things go
(not expecting any difference in behavior based on my read of this,
though).
On Sat, Dec 26, 2015 at 3:42 PM, Yann E. MORIN <yann.morin.1998@free.fr> wrote:
> From: Steven Noonan <steven@uplinklabs.net>
>
> Currently, we only support two levels of stach-smashing protection:
> - entirely disabled,
> - protect _all_ functions with -fstack-protector-all.
>
> -fstack-protector-all tends to be far too aggressive and impacts
> performance too much to be worth on a real product.
>
> Add a choice that allows us to select between different levels of
> stack-smashing protection:
> - none
> - basic (NEW)
> - strong (NEW)
> - all
>
> The differences are documented in the GCC online documentation:
> https://gcc.gnu.org/onlinedocs/gcc-4.9.2/gcc/Optimize-Options.html
>
> Signed-off-by: Steven Noonan <steven@uplinklabs.net>
> [yann.morin.1998 at free.fr:
> - rebase
> - add legacy handling
> - SSP-strong depends on gcc >= 4.9
> - slightly simple ifeq-block in package/Makefile.in
> - keep the comment in the choice; add a comment shen strong is not
> available
> - update commit log
> ]
> Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
>
> ---
> Changes v1 -> v2:
> - see commit log ;-) (Yann)
>
> ---
> Note: I (Yann) have only slightly tested this patch. More testing is in
> order before we can apply this. Steven, care to see if it still fits
> your need? Thanks! :-)
> ---
> Config.in | 50 +++++++++++++++++++++++++++++++++++++++++++++-----
> Config.in.legacy | 8 ++++++++
> package/Makefile.in | 8 +++++++-
> 3 files changed, 60 insertions(+), 6 deletions(-)
>
> diff --git a/Config.in b/Config.in
> index 0be44d9..1e85d78 100644
> --- a/Config.in
> +++ b/Config.in
> @@ -522,12 +522,14 @@ config BR2_GOOGLE_BREAKPAD_INCLUDE_FILES
>
> endif
>
> -config BR2_ENABLE_SSP
> +choice
> bool "build code with Stack Smashing Protection"
> - depends on BR2_TOOLCHAIN_HAS_SSP
> + default BR2_SSP_ALL if BR2_ENABLE_SSP # legacy
> + default BR2_SSP_STRONG if BR2_TOOLCHAIN_GCC_AT_LEAST_4_9
> + default BR2_SSP_REGULAR
> help
> - Enable stack smashing protection support using GCCs
> - -fstack-protector-all option.
> + Enable stack smashing protection support using GCC's
> + -fstack-protector option family.
>
> See http://www.linuxfromscratch.org/hints/downloads/files/ssp.txt
> for details.
> @@ -536,9 +538,47 @@ config BR2_ENABLE_SSP
> support. This is always the case for glibc and eglibc
> toolchain, but is optional in uClibc toolchains.
>
> -comment "enabling Stack Smashing Protection requires support in the toolchain"
> +config BR2_SSP_NONE
> + bool "None"
> + help
> + Disable stack-smashing protection.
> +
> +comment "Stack Smashing Protection needs a toolchain w/ SSP"
> depends on !BR2_TOOLCHAIN_HAS_SSP
>
> +config BR2_SSP_REGULAR
> + bool "-fstack-protector"
> + depends on BR2_TOOLCHAIN_HAS_SSP
> + help
> + Emit extra code to check for buffer overflows, such as stack
> + smashing attacks. This is done by adding a guard variable to
> + functions with vulnerable objects. This includes functions
> + that call alloca, and functions with buffers larger than 8
> + bytes. The guards are initialized when a function is entered
> + and then checked when the function exits. If a guard check
> + fails, an error message is printed and the program exits.
> +
> +config BR2_SSP_STRONG
> + bool "-fstack-protector-strong"
> + depends on BR2_TOOLCHAIN_HAS_SSP
> + depends on BR2_TOOLCHAIN_GCC_AT_LEAST_4_9
> + help
> + Like -fstack-protector but includes additional functions to be
> + protected - those that have local array definitions, or have
> + references to local frame addresses.
> +
> +comment "Stack Smashing Protection strong needs a toolchain w/ gcc >= 4.9"
> + depends on BR2_TOOLCHAIN_HAS_SSP
> + depends on !BR2_TOOLCHAIN_GCC_AT_LEAST_4_9
> +
> +config BR2_SSP_ALL
> + bool "-fstack-protector-all"
> + depends on BR2_TOOLCHAIN_HAS_SSP
> + help
> + Like -fstack-protector except that all functions are protected.
> +
> +endchoice
> +
> choice
> bool "libraries"
> default BR2_SHARED_LIBS if BR2_BINFMT_SUPPORTS_SHARED
> diff --git a/Config.in.legacy b/Config.in.legacy
> index 2628796..5d45d04 100644
> --- a/Config.in.legacy
> +++ b/Config.in.legacy
> @@ -145,6 +145,14 @@ endif
> ###############################################################################
> comment "Legacy options removed in 2016.02"
>
> +# BR2_ENABLE_SSP is still referenced in Config.in (default in choice)
> +config BR2_ENABLE_SSP
> + bool "Stack Smashing protection now has different levels"
> + help
> + The protection offered by SSP can now be selected from different
> + protection levels. Be sure to review the SSP level in the build
> + options menu.
> +
> config BR2_PACKAGE_DIRECTFB_CLE266
> bool "cle266 driver for directfb removed"
> select BR2_LEGACY
> diff --git a/package/Makefile.in b/package/Makefile.in
> index 82a66c2..c5652af 100644
> --- a/package/Makefile.in
> +++ b/package/Makefile.in
> @@ -159,7 +159,13 @@ TARGET_CFLAGS += -msep-data
> TARGET_CXXFLAGS += -msep-data
> endif
>
> -ifeq ($(BR2_ENABLE_SSP),y)
> +ifeq ($(BR2_SSP_REGULAR),y)
> +TARGET_CFLAGS += -fstack-protector
> +TARGET_CXXFLAGS += -fstack-protector
> +else ifeq ($(BR2_SSP_STRONG),y)
> +TARGET_CFLAGS += -fstack-protector-strong
> +TARGET_CXXFLAGS += -fstack-protector-strong
> +else ifeq ($(BR2_SSP_ALL),y)
> TARGET_CFLAGS += -fstack-protector-all
> TARGET_CXXFLAGS += -fstack-protector-all
> endif
> --
> 1.9.1
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Buildroot] [PATCHv2] toolchain: granular choice for stack protector
2015-12-27 0:27 ` Steven Noonan
@ 2015-12-27 9:23 ` Yann E. MORIN
0 siblings, 0 replies; 7+ messages in thread
From: Yann E. MORIN @ 2015-12-27 9:23 UTC (permalink / raw)
To: buildroot
Steven, All,
On 2015-12-26 16:27 -0800, Steven Noonan spake thusly:
> LGTM. Also looks like a better implementation than what I've been
> using (like the BR2_TOOLCHAIN_GCC_AT_LEAST_4_9 usage).
GCC_AT_LEAST_X_Y has been introduced after you sent your patch, so
indeed you could not have used it. ;-)
> The next time I
> rebase my tree I'll include this version instead and see how things go
> (not expecting any difference in behavior based on my read of this,
> though).
Thanks! :-)
Regards,
Yann E. MORIN.
> On Sat, Dec 26, 2015 at 3:42 PM, Yann E. MORIN <yann.morin.1998@free.fr> wrote:
> > From: Steven Noonan <steven@uplinklabs.net>
> >
> > Currently, we only support two levels of stach-smashing protection:
> > - entirely disabled,
> > - protect _all_ functions with -fstack-protector-all.
> >
> > -fstack-protector-all tends to be far too aggressive and impacts
> > performance too much to be worth on a real product.
> >
> > Add a choice that allows us to select between different levels of
> > stack-smashing protection:
> > - none
> > - basic (NEW)
> > - strong (NEW)
> > - all
> >
> > The differences are documented in the GCC online documentation:
> > https://gcc.gnu.org/onlinedocs/gcc-4.9.2/gcc/Optimize-Options.html
> >
> > Signed-off-by: Steven Noonan <steven@uplinklabs.net>
> > [yann.morin.1998 at free.fr:
> > - rebase
> > - add legacy handling
> > - SSP-strong depends on gcc >= 4.9
> > - slightly simple ifeq-block in package/Makefile.in
> > - keep the comment in the choice; add a comment shen strong is not
> > available
> > - update commit log
> > ]
> > Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
> >
> > ---
> > Changes v1 -> v2:
> > - see commit log ;-) (Yann)
> >
> > ---
> > Note: I (Yann) have only slightly tested this patch. More testing is in
> > order before we can apply this. Steven, care to see if it still fits
> > your need? Thanks! :-)
> > ---
> > Config.in | 50 +++++++++++++++++++++++++++++++++++++++++++++-----
> > Config.in.legacy | 8 ++++++++
> > package/Makefile.in | 8 +++++++-
> > 3 files changed, 60 insertions(+), 6 deletions(-)
> >
> > diff --git a/Config.in b/Config.in
> > index 0be44d9..1e85d78 100644
> > --- a/Config.in
> > +++ b/Config.in
> > @@ -522,12 +522,14 @@ config BR2_GOOGLE_BREAKPAD_INCLUDE_FILES
> >
> > endif
> >
> > -config BR2_ENABLE_SSP
> > +choice
> > bool "build code with Stack Smashing Protection"
> > - depends on BR2_TOOLCHAIN_HAS_SSP
> > + default BR2_SSP_ALL if BR2_ENABLE_SSP # legacy
> > + default BR2_SSP_STRONG if BR2_TOOLCHAIN_GCC_AT_LEAST_4_9
> > + default BR2_SSP_REGULAR
> > help
> > - Enable stack smashing protection support using GCCs
> > - -fstack-protector-all option.
> > + Enable stack smashing protection support using GCC's
> > + -fstack-protector option family.
> >
> > See http://www.linuxfromscratch.org/hints/downloads/files/ssp.txt
> > for details.
> > @@ -536,9 +538,47 @@ config BR2_ENABLE_SSP
> > support. This is always the case for glibc and eglibc
> > toolchain, but is optional in uClibc toolchains.
> >
> > -comment "enabling Stack Smashing Protection requires support in the toolchain"
> > +config BR2_SSP_NONE
> > + bool "None"
> > + help
> > + Disable stack-smashing protection.
> > +
> > +comment "Stack Smashing Protection needs a toolchain w/ SSP"
> > depends on !BR2_TOOLCHAIN_HAS_SSP
> >
> > +config BR2_SSP_REGULAR
> > + bool "-fstack-protector"
> > + depends on BR2_TOOLCHAIN_HAS_SSP
> > + help
> > + Emit extra code to check for buffer overflows, such as stack
> > + smashing attacks. This is done by adding a guard variable to
> > + functions with vulnerable objects. This includes functions
> > + that call alloca, and functions with buffers larger than 8
> > + bytes. The guards are initialized when a function is entered
> > + and then checked when the function exits. If a guard check
> > + fails, an error message is printed and the program exits.
> > +
> > +config BR2_SSP_STRONG
> > + bool "-fstack-protector-strong"
> > + depends on BR2_TOOLCHAIN_HAS_SSP
> > + depends on BR2_TOOLCHAIN_GCC_AT_LEAST_4_9
> > + help
> > + Like -fstack-protector but includes additional functions to be
> > + protected - those that have local array definitions, or have
> > + references to local frame addresses.
> > +
> > +comment "Stack Smashing Protection strong needs a toolchain w/ gcc >= 4.9"
> > + depends on BR2_TOOLCHAIN_HAS_SSP
> > + depends on !BR2_TOOLCHAIN_GCC_AT_LEAST_4_9
> > +
> > +config BR2_SSP_ALL
> > + bool "-fstack-protector-all"
> > + depends on BR2_TOOLCHAIN_HAS_SSP
> > + help
> > + Like -fstack-protector except that all functions are protected.
> > +
> > +endchoice
> > +
> > choice
> > bool "libraries"
> > default BR2_SHARED_LIBS if BR2_BINFMT_SUPPORTS_SHARED
> > diff --git a/Config.in.legacy b/Config.in.legacy
> > index 2628796..5d45d04 100644
> > --- a/Config.in.legacy
> > +++ b/Config.in.legacy
> > @@ -145,6 +145,14 @@ endif
> > ###############################################################################
> > comment "Legacy options removed in 2016.02"
> >
> > +# BR2_ENABLE_SSP is still referenced in Config.in (default in choice)
> > +config BR2_ENABLE_SSP
> > + bool "Stack Smashing protection now has different levels"
> > + help
> > + The protection offered by SSP can now be selected from different
> > + protection levels. Be sure to review the SSP level in the build
> > + options menu.
> > +
> > config BR2_PACKAGE_DIRECTFB_CLE266
> > bool "cle266 driver for directfb removed"
> > select BR2_LEGACY
> > diff --git a/package/Makefile.in b/package/Makefile.in
> > index 82a66c2..c5652af 100644
> > --- a/package/Makefile.in
> > +++ b/package/Makefile.in
> > @@ -159,7 +159,13 @@ TARGET_CFLAGS += -msep-data
> > TARGET_CXXFLAGS += -msep-data
> > endif
> >
> > -ifeq ($(BR2_ENABLE_SSP),y)
> > +ifeq ($(BR2_SSP_REGULAR),y)
> > +TARGET_CFLAGS += -fstack-protector
> > +TARGET_CXXFLAGS += -fstack-protector
> > +else ifeq ($(BR2_SSP_STRONG),y)
> > +TARGET_CFLAGS += -fstack-protector-strong
> > +TARGET_CXXFLAGS += -fstack-protector-strong
> > +else ifeq ($(BR2_SSP_ALL),y)
> > TARGET_CFLAGS += -fstack-protector-all
> > TARGET_CXXFLAGS += -fstack-protector-all
> > endif
> > --
> > 1.9.1
> >
--
.-----------------.--------------------.------------------.--------------------.
| Yann E. MORIN | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: |
| +33 662 376 056 | Software Designer | \ / CAMPAIGN | ___ |
| +33 223 225 172 `------------.-------: X AGAINST | \e/ There is no |
| http://ymorin.is-a-geek.org/ | _/*\_ | / \ HTML MAIL | v conspiracy. |
'------------------------------^-------^------------------^--------------------'
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Buildroot] [PATCHv2] toolchain: granular choice for stack protector
2015-12-26 23:42 [Buildroot] [PATCHv2] toolchain: granular choice for stack protector Yann E. MORIN
2015-12-27 0:27 ` Steven Noonan
@ 2015-12-27 10:19 ` Thomas Petazzoni
2015-12-27 10:26 ` Yann E. MORIN
1 sibling, 1 reply; 7+ messages in thread
From: Thomas Petazzoni @ 2015-12-27 10:19 UTC (permalink / raw)
To: buildroot
Yann,
On Sun, 27 Dec 2015 00:42:06 +0100, Yann E. MORIN wrote:
> -config BR2_ENABLE_SSP
> +choice
> bool "build code with Stack Smashing Protection"
> - depends on BR2_TOOLCHAIN_HAS_SSP
> + default BR2_SSP_ALL if BR2_ENABLE_SSP # legacy
> + default BR2_SSP_STRONG if BR2_TOOLCHAIN_GCC_AT_LEAST_4_9
I don't understand this part. Why would we now defalut on
BR2_SSP_STRONG if gcc >= 4.9 ?
I think we should keep the default of not having SSP enabled.
Best regards,
Thomas
--
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Buildroot] [PATCHv2] toolchain: granular choice for stack protector
2015-12-27 10:19 ` Thomas Petazzoni
@ 2015-12-27 10:26 ` Yann E. MORIN
2015-12-27 10:44 ` Steven Noonan
0 siblings, 1 reply; 7+ messages in thread
From: Yann E. MORIN @ 2015-12-27 10:26 UTC (permalink / raw)
To: buildroot
Thomas, All,
On 2015-12-27 11:19 +0100, Thomas Petazzoni spake thusly:
> On Sun, 27 Dec 2015 00:42:06 +0100, Yann E. MORIN wrote:
> > -config BR2_ENABLE_SSP
> > +choice
> > bool "build code with Stack Smashing Protection"
> > - depends on BR2_TOOLCHAIN_HAS_SSP
> > + default BR2_SSP_ALL if BR2_ENABLE_SSP # legacy
> > + default BR2_SSP_STRONG if BR2_TOOLCHAIN_GCC_AT_LEAST_4_9
>
> I don't understand this part. Why would we now defalut on
> BR2_SSP_STRONG if gcc >= 4.9 ?
Hmmm... I did not think too much about that. I just "updated" the patch
and kept its meaning as-is.
> I think we should keep the default of not having SSP enabled.
Yes, makes sense. At best, the change in the default should have been in
another patch.
I'll fix and respin.
Regards,
Yann E. MORIN.
--
.-----------------.--------------------.------------------.--------------------.
| Yann E. MORIN | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: |
| +33 662 376 056 | Software Designer | \ / CAMPAIGN | ___ |
| +33 223 225 172 `------------.-------: X AGAINST | \e/ There is no |
| http://ymorin.is-a-geek.org/ | _/*\_ | / \ HTML MAIL | v conspiracy. |
'------------------------------^-------^------------------^--------------------'
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Buildroot] [PATCHv2] toolchain: granular choice for stack protector
2015-12-27 10:26 ` Yann E. MORIN
@ 2015-12-27 10:44 ` Steven Noonan
2015-12-27 10:55 ` Yann E. MORIN
0 siblings, 1 reply; 7+ messages in thread
From: Steven Noonan @ 2015-12-27 10:44 UTC (permalink / raw)
To: buildroot
On Sun, Dec 27, 2015 at 2:26 AM, Yann E. MORIN <yann.morin.1998@free.fr> wrote:
> Thomas, All,
>
> On 2015-12-27 11:19 +0100, Thomas Petazzoni spake thusly:
>> On Sun, 27 Dec 2015 00:42:06 +0100, Yann E. MORIN wrote:
>> > -config BR2_ENABLE_SSP
>> > +choice
>> > bool "build code with Stack Smashing Protection"
>> > - depends on BR2_TOOLCHAIN_HAS_SSP
>> > + default BR2_SSP_ALL if BR2_ENABLE_SSP # legacy
>> > + default BR2_SSP_STRONG if BR2_TOOLCHAIN_GCC_AT_LEAST_4_9
>>
>> I don't understand this part. Why would we now defalut on
>> BR2_SSP_STRONG if gcc >= 4.9 ?
>
> Hmmm... I did not think too much about that. I just "updated" the patch
> and kept its meaning as-is.
>
>> I think we should keep the default of not having SSP enabled.
>
> Yes, makes sense. At best, the change in the default should have been in
> another patch.
I could be wrong, but I *think* BuildRoot used to default to SSP on.
If not, I don't know why I would have changed the default. I'm not a
particularly big fan of SSP to begin with, so I'd have no incentive to
default it enabled.
> I'll fix and respin.
>
> Regards,
> Yann E. MORIN.
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Buildroot] [PATCHv2] toolchain: granular choice for stack protector
2015-12-27 10:44 ` Steven Noonan
@ 2015-12-27 10:55 ` Yann E. MORIN
0 siblings, 0 replies; 7+ messages in thread
From: Yann E. MORIN @ 2015-12-27 10:55 UTC (permalink / raw)
To: buildroot
Steven, All,
On 2015-12-27 02:44 -0800, Steven Noonan spake thusly:
> On Sun, Dec 27, 2015 at 2:26 AM, Yann E. MORIN <yann.morin.1998@free.fr> wrote:
> > On 2015-12-27 11:19 +0100, Thomas Petazzoni spake thusly:
> >> On Sun, 27 Dec 2015 00:42:06 +0100, Yann E. MORIN wrote:
> >> > -config BR2_ENABLE_SSP
> >> > +choice
> >> > bool "build code with Stack Smashing Protection"
> >> > - depends on BR2_TOOLCHAIN_HAS_SSP
> >> > + default BR2_SSP_ALL if BR2_ENABLE_SSP # legacy
> >> > + default BR2_SSP_STRONG if BR2_TOOLCHAIN_GCC_AT_LEAST_4_9
> >>
> >> I don't understand this part. Why would we now defalut on
> >> BR2_SSP_STRONG if gcc >= 4.9 ?
> >
> > Hmmm... I did not think too much about that. I just "updated" the patch
> > and kept its meaning as-is.
> >
> >> I think we should keep the default of not having SSP enabled.
> >
> > Yes, makes sense. At best, the change in the default should have been in
> > another patch.
>
> I could be wrong, but I *think* BuildRoot used to default to SSP on.
> If not, I don't know why I would have changed the default. I'm not a
> particularly big fan of SSP to begin with, so I'd have no incentive to
> default it enabled.
OK, so I will definitely remove the new defaults before I respin.
Thanks for the feedback! :-)
Regards,
Yann E. MORIN.
> > I'll fix and respin.
> >
> > Regards,
> > Yann E. MORIN.
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^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2015-12-27 10:55 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-12-26 23:42 [Buildroot] [PATCHv2] toolchain: granular choice for stack protector Yann E. MORIN
2015-12-27 0:27 ` Steven Noonan
2015-12-27 9:23 ` Yann E. MORIN
2015-12-27 10:19 ` Thomas Petazzoni
2015-12-27 10:26 ` Yann E. MORIN
2015-12-27 10:44 ` Steven Noonan
2015-12-27 10:55 ` Yann E. MORIN
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