[REGRESSION] v6.12.35: (build) kallsyms.h:21:10: fatal error: execinfo.h: No such file or directory

[REGRESSION] v6.12.35: (build) kallsyms.h:21:10: fatal error: execinfo.h: No such file or directory

[Natanael Copa]

Hi!

I bumped into a build regression when building Alpine Linux kernel 6.12.35 on x86_64:

In file included from ../arch/x86/tools/insn_decoder_test.c:13:
../tools/include/linux/kallsyms.h:21:10: fatal error: execinfo.h: No such file or directory
   21 | #include <execinfo.h>
      |          ^~~~~~~~~~~~
compilation terminated.

The 6.12.34 kernel built just fine.

I bisected it to:

commit b8abcba6e4aec53868dfe44f97270fc4dee0df2a (HEAD)
Author: Sergio Gonz_lez Collado <sergio.collado@gmail.com>
Date:   Sun Mar 2 23:15:18 2025 +0100

    Kunit to check the longest symbol length
    
    commit c104c16073b7fdb3e4eae18f66f4009f6b073d6f upstream.
    
which has this hunk:

diff --git a/arch/x86/tools/insn_decoder_test.c b/arch/x86/tools/insn_decoder_test.c
index 472540aeabc2..6c2986d2ad11 100644
--- a/arch/x86/tools/insn_decoder_test.c
+++ b/arch/x86/tools/insn_decoder_test.c
@@ -10,6 +10,7 @@
 #include <assert.h>
 #include <unistd.h>
 #include <stdarg.h>
+#include <linux/kallsyms.h>
 
 #define unlikely(cond) (cond)
 
@@ -106,7 +107,7 @@ static void parse_args(int argc, char **argv)
        }
 }
 
-#define BUFSIZE 256
+#define BUFSIZE (256 + KSYM_NAME_LEN)
 
 int main(int argc, char **argv)
 {

It looks like the linux/kallsyms.h was included to get KSYM_NAME_LEN.
Unfortunately it also introduced the include of execinfo.h, which does
not exist on musl libc.

This has previously been reported to and tried fixed:
https://lore.kernel.org/stable/DB0OSTC6N4TL.2NK75K2CWE9JV@pwned.life/T/#t

Would it be an idea to revert commit b8abcba6e4ae til we have a proper
solution for this?

Thanks!

-nc

Re: [REGRESSION] v6.12.35: (build) kallsyms.h:21:10: fatal error: execinfo.h: No such file or directory

[Greg Kroah-Hartman]

On Tue, Jul 01, 2025 at 02:10:26PM +0200, Natanael Copa wrote:
> Hi!
> 
> I bumped into a build regression when building Alpine Linux kernel 6.12.35 on x86_64:
> 
> In file included from ../arch/x86/tools/insn_decoder_test.c:13:
> ../tools/include/linux/kallsyms.h:21:10: fatal error: execinfo.h: No such file or directory
>    21 | #include <execinfo.h>
>       |          ^~~~~~~~~~~~
> compilation terminated.
> 
> The 6.12.34 kernel built just fine.
> 
> I bisected it to:
> 
> commit b8abcba6e4aec53868dfe44f97270fc4dee0df2a (HEAD)
> Author: Sergio Gonz_lez Collado <sergio.collado@gmail.com>
> Date:   Sun Mar 2 23:15:18 2025 +0100
> 
>     Kunit to check the longest symbol length
>     
>     commit c104c16073b7fdb3e4eae18f66f4009f6b073d6f upstream.
>     
> which has this hunk:
> 
> diff --git a/arch/x86/tools/insn_decoder_test.c b/arch/x86/tools/insn_decoder_test.c
> index 472540aeabc2..6c2986d2ad11 100644
> --- a/arch/x86/tools/insn_decoder_test.c
> +++ b/arch/x86/tools/insn_decoder_test.c
> @@ -10,6 +10,7 @@
>  #include <assert.h>
>  #include <unistd.h>
>  #include <stdarg.h>
> +#include <linux/kallsyms.h>
>  
>  #define unlikely(cond) (cond)
>  
> @@ -106,7 +107,7 @@ static void parse_args(int argc, char **argv)
>         }
>  }
>  
> -#define BUFSIZE 256
> +#define BUFSIZE (256 + KSYM_NAME_LEN)
>  
>  int main(int argc, char **argv)
>  {
> 
> It looks like the linux/kallsyms.h was included to get KSYM_NAME_LEN.
> Unfortunately it also introduced the include of execinfo.h, which does
> not exist on musl libc.
> 
> This has previously been reported to and tried fixed:
> https://lore.kernel.org/stable/DB0OSTC6N4TL.2NK75K2CWE9JV@pwned.life/T/#t
> 
> Would it be an idea to revert commit b8abcba6e4ae til we have a proper
> solution for this?

Please get the fix in Linus's tree first and then we can backport it as
needed.

thanks,

greg k-h

Re: [REGRESSION] v6.12.35: (build) kallsyms.h:21:10: fatal error: execinfo.h: No such file or directory

[Achill Gilgenast]

On Tue Jul 1, 2025 at 2:26 PM CEST, Greg Kroah-Hartman wrote:
> On Tue, Jul 01, 2025 at 02:10:26PM +0200, Natanael Copa wrote:
>> Hi!
>> 
>> I bumped into a build regression when building Alpine Linux kernel 6.12.35 on x86_64:
>> 
>> In file included from ../arch/x86/tools/insn_decoder_test.c:13:
>> ../tools/include/linux/kallsyms.h:21:10: fatal error: execinfo.h: No such file or directory
>>    21 | #include <execinfo.h>
>>       |          ^~~~~~~~~~~~
>> compilation terminated.
>> 
>> The 6.12.34 kernel built just fine.
>> 
>> I bisected it to:
>> 
>> commit b8abcba6e4aec53868dfe44f97270fc4dee0df2a (HEAD)
>> Author: Sergio Gonz_lez Collado <sergio.collado@gmail.com>
>> Date:   Sun Mar 2 23:15:18 2025 +0100
>> 
>>     Kunit to check the longest symbol length
>>     
>>     commit c104c16073b7fdb3e4eae18f66f4009f6b073d6f upstream.
>>     
>> which has this hunk:
>> 
>> diff --git a/arch/x86/tools/insn_decoder_test.c b/arch/x86/tools/insn_decoder_test.c
>> index 472540aeabc2..6c2986d2ad11 100644
>> --- a/arch/x86/tools/insn_decoder_test.c
>> +++ b/arch/x86/tools/insn_decoder_test.c
>> @@ -10,6 +10,7 @@
>>  #include <assert.h>
>>  #include <unistd.h>
>>  #include <stdarg.h>
>> +#include <linux/kallsyms.h>
>>  
>>  #define unlikely(cond) (cond)
>>  
>> @@ -106,7 +107,7 @@ static void parse_args(int argc, char **argv)
>>         }
>>  }
>>  
>> -#define BUFSIZE 256
>> +#define BUFSIZE (256 + KSYM_NAME_LEN)
>>  
>>  int main(int argc, char **argv)
>>  {
>> 
>> It looks like the linux/kallsyms.h was included to get KSYM_NAME_LEN.
>> Unfortunately it also introduced the include of execinfo.h, which does
>> not exist on musl libc.
>> 
>> This has previously been reported to and tried fixed:
>> https://lore.kernel.org/stable/DB0OSTC6N4TL.2NK75K2CWE9JV@pwned.life/T/#t
>> 
>> Would it be an idea to revert commit b8abcba6e4ae til we have a proper
>> solution for this?
>
> Please get the fix in Linus's tree first and then we can backport it as
> needed.

The patch now landed in Linus's tree as a95743b53031 ("kallsyms: fix
build without execinfo"). Please backport it into the stable trees.

Re: [REGRESSION] v6.12.35: (build) kallsyms.h:21:10: fatal error: execinfo.h: No such file or directory

[Greg Kroah-Hartman]

On Sun, Jul 13, 2025 at 04:27:36PM +0200, Achill Gilgenast wrote:
> On Tue Jul 1, 2025 at 2:26 PM CEST, Greg Kroah-Hartman wrote:
> > On Tue, Jul 01, 2025 at 02:10:26PM +0200, Natanael Copa wrote:
> >> Hi!
> >> 
> >> I bumped into a build regression when building Alpine Linux kernel 6.12.35 on x86_64:
> >> 
> >> In file included from ../arch/x86/tools/insn_decoder_test.c:13:
> >> ../tools/include/linux/kallsyms.h:21:10: fatal error: execinfo.h: No such file or directory
> >>    21 | #include <execinfo.h>
> >>       |          ^~~~~~~~~~~~
> >> compilation terminated.
> >> 
> >> The 6.12.34 kernel built just fine.
> >> 
> >> I bisected it to:
> >> 
> >> commit b8abcba6e4aec53868dfe44f97270fc4dee0df2a (HEAD)
> >> Author: Sergio Gonz_lez Collado <sergio.collado@gmail.com>
> >> Date:   Sun Mar 2 23:15:18 2025 +0100
> >> 
> >>     Kunit to check the longest symbol length
> >>     
> >>     commit c104c16073b7fdb3e4eae18f66f4009f6b073d6f upstream.
> >>     
> >> which has this hunk:
> >> 
> >> diff --git a/arch/x86/tools/insn_decoder_test.c b/arch/x86/tools/insn_decoder_test.c
> >> index 472540aeabc2..6c2986d2ad11 100644
> >> --- a/arch/x86/tools/insn_decoder_test.c
> >> +++ b/arch/x86/tools/insn_decoder_test.c
> >> @@ -10,6 +10,7 @@
> >>  #include <assert.h>
> >>  #include <unistd.h>
> >>  #include <stdarg.h>
> >> +#include <linux/kallsyms.h>
> >>  
> >>  #define unlikely(cond) (cond)
> >>  
> >> @@ -106,7 +107,7 @@ static void parse_args(int argc, char **argv)
> >>         }
> >>  }
> >>  
> >> -#define BUFSIZE 256
> >> +#define BUFSIZE (256 + KSYM_NAME_LEN)
> >>  
> >>  int main(int argc, char **argv)
> >>  {
> >> 
> >> It looks like the linux/kallsyms.h was included to get KSYM_NAME_LEN.
> >> Unfortunately it also introduced the include of execinfo.h, which does
> >> not exist on musl libc.
> >> 
> >> This has previously been reported to and tried fixed:
> >> https://lore.kernel.org/stable/DB0OSTC6N4TL.2NK75K2CWE9JV@pwned.life/T/#t
> >> 
> >> Would it be an idea to revert commit b8abcba6e4ae til we have a proper
> >> solution for this?
> >
> > Please get the fix in Linus's tree first and then we can backport it as
> > needed.
> 
> The patch now landed in Linus's tree as a95743b53031 ("kallsyms: fix
> build without execinfo"). Please backport it into the stable trees.

Already all queued up!

Thanks for letting us know.

greg k-h

Re: [REGRESSION] v6.12.35: (build) kallsyms.h:21:10: fatal error: execinfo.h: No such file or directory

[Achill Gilgenast]

On Sun Jul 13, 2025 at 4:38 PM CEST, Greg Kroah-Hartman wrote:
> On Sun, Jul 13, 2025 at 04:27:36PM +0200, Achill Gilgenast wrote:
>> On Tue Jul 1, 2025 at 2:26 PM CEST, Greg Kroah-Hartman wrote:
>> > On Tue, Jul 01, 2025 at 02:10:26PM +0200, Natanael Copa wrote:
>> >> Hi!
>> >> 
>> >> I bumped into a build regression when building Alpine Linux kernel 6.12.35 on x86_64:
>> >> 
>> >> In file included from ../arch/x86/tools/insn_decoder_test.c:13:
>> >> ../tools/include/linux/kallsyms.h:21:10: fatal error: execinfo.h: No such file or directory
>> >>    21 | #include <execinfo.h>
>> >>       |          ^~~~~~~~~~~~
>> >> compilation terminated.
>> >> 
>> >> The 6.12.34 kernel built just fine.
>> >> 
>> >> I bisected it to:
>> >> 
>> >> commit b8abcba6e4aec53868dfe44f97270fc4dee0df2a (HEAD)
>> >> Author: Sergio Gonz_lez Collado <sergio.collado@gmail.com>
>> >> Date:   Sun Mar 2 23:15:18 2025 +0100
>> >> 
>> >>     Kunit to check the longest symbol length
>> >>     
>> >>     commit c104c16073b7fdb3e4eae18f66f4009f6b073d6f upstream.
>> >>     
>> >> which has this hunk:
>> >> 
>> >> diff --git a/arch/x86/tools/insn_decoder_test.c b/arch/x86/tools/insn_decoder_test.c
>> >> index 472540aeabc2..6c2986d2ad11 100644
>> >> --- a/arch/x86/tools/insn_decoder_test.c
>> >> +++ b/arch/x86/tools/insn_decoder_test.c
>> >> @@ -10,6 +10,7 @@
>> >>  #include <assert.h>
>> >>  #include <unistd.h>
>> >>  #include <stdarg.h>
>> >> +#include <linux/kallsyms.h>
>> >>  
>> >>  #define unlikely(cond) (cond)
>> >>  
>> >> @@ -106,7 +107,7 @@ static void parse_args(int argc, char **argv)
>> >>         }
>> >>  }
>> >>  
>> >> -#define BUFSIZE 256
>> >> +#define BUFSIZE (256 + KSYM_NAME_LEN)
>> >>  
>> >>  int main(int argc, char **argv)
>> >>  {
>> >> 
>> >> It looks like the linux/kallsyms.h was included to get KSYM_NAME_LEN.
>> >> Unfortunately it also introduced the include of execinfo.h, which does
>> >> not exist on musl libc.
>> >> 
>> >> This has previously been reported to and tried fixed:
>> >> https://lore.kernel.org/stable/DB0OSTC6N4TL.2NK75K2CWE9JV@pwned.life/T/#t
>> >> 
>> >> Would it be an idea to revert commit b8abcba6e4ae til we have a proper
>> >> solution for this?
>> >
>> > Please get the fix in Linus's tree first and then we can backport it as
>> > needed.
>> 
>> The patch now landed in Linus's tree as a95743b53031 ("kallsyms: fix
>> build without execinfo"). Please backport it into the stable trees.
>
> Already all queued up!
>
> Thanks for letting us know.

Nice, thanks!

Re: [REGRESSION] v6.12.35: (build) kallsyms.h:21:10: fatal error: execinfo.h: No such file or directory

[Sergio González Collado]

Hello,

 Thanks for pointing that out. I was not aware of it.

On Tue, 1 Jul 2025 at 14:10, Natanael Copa <ncopa@alpinelinux.org> wrote:
>
> Hi!
>
> I bumped into a build regression when building Alpine Linux kernel 6.12.35 on x86_64:
>
> In file included from ../arch/x86/tools/insn_decoder_test.c:13:
> ../tools/include/linux/kallsyms.h:21:10: fatal error: execinfo.h: No such file or directory
>    21 | #include <execinfo.h>
>       |          ^~~~~~~~~~~~
> compilation terminated.
>
> The 6.12.34 kernel built just fine.
>
> I bisected it to:
>
> commit b8abcba6e4aec53868dfe44f97270fc4dee0df2a (HEAD)
> Author: Sergio Gonz_lez Collado <sergio.collado@gmail.com>
> Date:   Sun Mar 2 23:15:18 2025 +0100
>
>     Kunit to check the longest symbol length
>
>     commit c104c16073b7fdb3e4eae18f66f4009f6b073d6f upstream.
>
> which has this hunk:
>
> diff --git a/arch/x86/tools/insn_decoder_test.c b/arch/x86/tools/insn_decoder_test.c
> index 472540aeabc2..6c2986d2ad11 100644
> --- a/arch/x86/tools/insn_decoder_test.c
> +++ b/arch/x86/tools/insn_decoder_test.c
> @@ -10,6 +10,7 @@
>  #include <assert.h>
>  #include <unistd.h>
>  #include <stdarg.h>
> +#include <linux/kallsyms.h>
>
>  #define unlikely(cond) (cond)
>
> @@ -106,7 +107,7 @@ static void parse_args(int argc, char **argv)
>         }
>  }
>
> -#define BUFSIZE 256
> +#define BUFSIZE (256 + KSYM_NAME_LEN)
>
>  int main(int argc, char **argv)
>  {
>
> It looks like the linux/kallsyms.h was included to get KSYM_NAME_LEN.
> Unfortunately it also introduced the include of execinfo.h, which does
> not exist on musl libc.
>
> This has previously been reported to and tried fixed:
> https://lore.kernel.org/stable/DB0OSTC6N4TL.2NK75K2CWE9JV@pwned.life/T/#t
>
> Would it be an idea to revert commit b8abcba6e4ae til we have a proper
> solution for this?
>
> Thanks!
>
> -nc

Re: [REGRESSION] v6.12.35: (build) kallsyms.h:21:10: fatal error: execinfo.h: No such file or directory

[Natanael Copa]

On Tue, 1 Jul 2025 19:07:32 +0200
Sergio González Collado <sergio.collado@gmail.com> wrote:

> Hello,

Hi Sergio,

>  Thanks for pointing that out. I was not aware of it.

No worries. It happens. Just slightly unfortunate that it tickled down
to stable branches before it got fixed.

It is trivial to fix but I wonder what is the best way though. Achill
proposed to use #ifdef HAVE_BACKTRACE_SUPPORT in
tools/include/linux/kallsyms.h but it appears that this was included
only for KSYM_NAME_LEN.

KSYM_NAME_LEN appears to be defined multiple places:

$ rg 'KSYM_NAME_LEN\s+512'
include/linux/kallsyms.h
18:#define KSYM_NAME_LEN 512

tools/include/linux/kallsyms.h
9:#define KSYM_NAME_LEN 512

tools/lib/perf/include/perf/event.h
107:#define KSYM_NAME_LEN 512

tools/lib/symbol/kallsyms.h
10:#define KSYM_NAME_LEN 512

scripts/kallsyms.c
34:#define KSYM_NAME_LEN                512

So I wonder if it would be acceptable to simply:

diff --git a/arch/x86/tools/insn_decoder_test.c b/arch/x86/tools/insn_decoder_test.c
index 08cd913cbd4e..7916bf487ed2 100644
--- a/arch/x86/tools/insn_decoder_test.c
+++ b/arch/x86/tools/insn_decoder_test.c
@@ -10,7 +10,6 @@
 #include <assert.h>
 #include <unistd.h>
 #include <stdarg.h>
-#include <linux/kallsyms.h>
 
 #include <asm/insn.h>
 #include <inat.c>
@@ -105,6 +104,7 @@ static void parse_args(int argc, char **argv)
        }
 }
 
+#define KSYM_NAME_LEN 512
 #define BUFSIZE (256 + KSYM_NAME_LEN)
 
 int main(int argc, char **argv)

I am also confused with who should be in the CC list.

Thanks!
-nc
 
> On Tue, 1 Jul 2025 at 14:10, Natanael Copa <ncopa@alpinelinux.org> wrote:
> >
> > Hi!
> >
> > I bumped into a build regression when building Alpine Linux kernel 6.12.35 on x86_64:
> >
> > In file included from ../arch/x86/tools/insn_decoder_test.c:13:
> > ../tools/include/linux/kallsyms.h:21:10: fatal error: execinfo.h: No such file or directory
> >    21 | #include <execinfo.h>
> >       |          ^~~~~~~~~~~~
> > compilation terminated.
> >
> > The 6.12.34 kernel built just fine.
> >
> > I bisected it to:
> >
> > commit b8abcba6e4aec53868dfe44f97270fc4dee0df2a (HEAD)
> > Author: Sergio Gonz_lez Collado <sergio.collado@gmail.com>
> > Date:   Sun Mar 2 23:15:18 2025 +0100
> >
> >     Kunit to check the longest symbol length
> >
> >     commit c104c16073b7fdb3e4eae18f66f4009f6b073d6f upstream.
> >
> > which has this hunk:
> >
> > diff --git a/arch/x86/tools/insn_decoder_test.c b/arch/x86/tools/insn_decoder_test.c
> > index 472540aeabc2..6c2986d2ad11 100644
> > --- a/arch/x86/tools/insn_decoder_test.c
> > +++ b/arch/x86/tools/insn_decoder_test.c
> > @@ -10,6 +10,7 @@
> >  #include <assert.h>
> >  #include <unistd.h>
> >  #include <stdarg.h>
> > +#include <linux/kallsyms.h> 
> >
> >  #define unlikely(cond) (cond)
> >
> > @@ -106,7 +107,7 @@ static void parse_args(int argc, char **argv)
> >         }
> >  }
> >
> > -#define BUFSIZE 256
> > +#define BUFSIZE (256 + KSYM_NAME_LEN)
> >
> >  int main(int argc, char **argv)
> >  {
> >
> > It looks like the linux/kallsyms.h was included to get
> > KSYM_NAME_LEN. Unfortunately it also introduced the include of
> > execinfo.h, which does not exist on musl libc.
> >
> > This has previously been reported to and tried fixed:
> > https://lore.kernel.org/stable/DB0OSTC6N4TL.2NK75K2CWE9JV@pwned.life/T/#t
> >
> > Would it be an idea to revert commit b8abcba6e4ae til we have a
> > proper solution for this?
> >
> > Thanks!
> >
> > -nc  

Re: [REGRESSION] v6.12.35: (build) kallsyms.h:21:10: fatal error: execinfo.h: No such file or directory

[Achill Gilgenast]

On Wed Jul 2, 2025 at 12:42 PM CEST, Natanael Copa wrote:
> On Tue, 1 Jul 2025 19:07:32 +0200
> Sergio González Collado <sergio.collado@gmail.com> wrote:
>
>> Hello,
>
> Hi Sergio,
>
>>  Thanks for pointing that out. I was not aware of it.
>
> No worries. It happens. Just slightly unfortunate that it tickled down
> to stable branches before it got fixed.
>
> It is trivial to fix but I wonder what is the best way though. Achill
> proposed to use #ifdef HAVE_BACKTRACE_SUPPORT in
> tools/include/linux/kallsyms.h but it appears that this was included
> only for KSYM_NAME_LEN.

This would still not resolve the actual issue that execinfo.h is
included if built without backtrace support and kallsyms.h gets
included.

#ifdef HAVE_BACKTRACE_SUPPORT can be seen in other places in tools/,
where it is used exactly like I did in
https://lore.kernel.org/stable/20250622014608.448718-1-fossdd@pwned.life/.