Messages in this thread | | | Date | Wed, 23 Feb 2022 00:50:21 -0800 | Subject | Re: [PATCH] [PATCH] AARCH64: Add gcc Shadow Call Stack support | From | Dan Li <> |
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On 2/22/22 08:16, Nathan Chancellor wrote: > On Tue, Feb 22, 2022 at 01:57:36AM -0800, Dan Li wrote: >> Shadow call stack is available in GCC > 11.2.0, this patch makes >> the corresponding kernel configuration available when compiling >> the kernel with gcc. >> config SHADOW_CALL_STACK >> - bool "Clang Shadow Call Stack" >> - depends on CC_IS_CLANG && ARCH_SUPPORTS_SHADOW_CALL_STACK >> + bool "Shadow Call Stack" >> + depends on ARCH_SUPPORTS_SHADOW_CALL_STACK >> depends on DYNAMIC_FTRACE_WITH_REGS || !FUNCTION_GRAPH_TRACER >> help >> - This option enables Clang's Shadow Call Stack, which uses a >> + This option enables Clang/GCC's Shadow Call Stack, which uses a > > I wonder if we want to just ditch the mention of the compiler if both > support it? >
My intention is to remind users that this is a compiler feature. But since there is also a hint in CC_HAVE_SHADOW_CALL_STACK: +# Supported by clang >= 7.0 or GCC ...
Removing the specific compiler here also looks fine to me. Would this look better?
"This option enables Shadow Call Stack, which uses a ..."
or maybe:
"This option enables compiler's Shadow Call Stack, which uses a ..."
>> shadow stack to protect function return addresses from being >> overwritten by an attacker. More information can be found in >> Clang's documentation: >> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig >> index 09b885cc4db5..a48a604301aa 100644 >> --- a/arch/arm64/Kconfig >> +++ b/arch/arm64/Kconfig >> @@ -1255,7 +1255,7 @@ config HW_PERF_EVENTS >> config ARCH_HAS_FILTER_PGPROT >> def_bool y >> >> -# Supported by clang >= 7.0 >> +# Supported by clang >= 7.0 or GCC > 11.2.0 > > Same thing here, although eventually there may be a minimum GCC version > bump to something newer than 11.2.0, which would allow us to just drop > CONFIG_CC_HAVE_SHADOW_CALL_STACK altogether. No strong opinion. >
As Guenter said, I thought maybe we could mark the minimum available version for users :)
Thanks, Dan.
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