[PATCH] glibc: Enable backtrace from abort on ARM

[PATCH] glibc: Enable backtrace from abort on ARM

[Mark Hatle]

From: Yuanjie Huang <yuanjie.huang@windriver.com>

ARM stack frames for abort and raise were limited to the the actual
abort and raise call, such as:

Obtained 4 stack frames.
./test-app(print_trace+0x1c) [0x10a08]
./test-app() [0x10b3c]
/lib/libc.so.6(__default_sa_restorer+0) [0x4adae1e0]
/lib/libc.so.6(gsignal+0xa0) [0x4adacf74]

This is not terribly useful when trying to figure out what function
may have called called the abort, especially when using pthreads.

After the change the trace would now look like:

Obtained 8 stack frames.
./test-app(print_trace+0x1c) [0x10a08]
./test-app() [0x10b3c]
/lib/libc.so.6(__default_sa_restorer+0) [0x4befe1e0]
/lib/libc.so.6(gsignal+0xa0) [0x4befcf74]
/lib/libc.so.6(abort+0x134) [0x4befe358]
./test-app(dummy_function+0x50) [0x10adc]
./test-app(main+0xd4) [0x10c24]
/lib/libc.so.6(__libc_start_main+0x114) [0x4bee7a58]

Signed-off-by: Yuanjie Huang <yuanjie.huang@windriver.com>
Signed-off-by: Mark Hatle <mark.hatle@windriver.com>
---
 meta/recipes-core/glibc/glibc.inc | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meta/recipes-core/glibc/glibc.inc b/meta/recipes-core/glibc/glibc.inc
index e85c7044a0..358e69be67 100644
--- a/meta/recipes-core/glibc/glibc.inc
+++ b/meta/recipes-core/glibc/glibc.inc
@@ -78,3 +78,9 @@ do_configure_prepend() {
 }
 
 GLIBC_ADDONS ?= "nptl,libidn"
+
+# Enable backtrace from abort()
+do_configure_append_arm () {
+	echo "CFLAGS-abort.c = -funwind-tables" >> ${B}/configparms
+	echo "CFLAGS-raise.c = -funwind-tables" >> ${B}/configparms
+}
-- 
2.11.0.rc1

Re: [morty] [PATCH] glibc: Enable backtrace from abort on ARM

[Mark Hatle]

Forgot to mention, also applicable to Morty.

--Mark

On 12/8/16 1:03 PM, Mark Hatle wrote:
> From: Yuanjie Huang <yuanjie.huang@windriver.com>
> 
> ARM stack frames for abort and raise were limited to the the actual
> abort and raise call, such as:
> 
> Obtained 4 stack frames.
> ./test-app(print_trace+0x1c) [0x10a08]
> ./test-app() [0x10b3c]
> /lib/libc.so.6(__default_sa_restorer+0) [0x4adae1e0]
> /lib/libc.so.6(gsignal+0xa0) [0x4adacf74]
> 
> This is not terribly useful when trying to figure out what function
> may have called called the abort, especially when using pthreads.
> 
> After the change the trace would now look like:
> 
> Obtained 8 stack frames.
> ./test-app(print_trace+0x1c) [0x10a08]
> ./test-app() [0x10b3c]
> /lib/libc.so.6(__default_sa_restorer+0) [0x4befe1e0]
> /lib/libc.so.6(gsignal+0xa0) [0x4befcf74]
> /lib/libc.so.6(abort+0x134) [0x4befe358]
> ./test-app(dummy_function+0x50) [0x10adc]
> ./test-app(main+0xd4) [0x10c24]
> /lib/libc.so.6(__libc_start_main+0x114) [0x4bee7a58]
> 
> Signed-off-by: Yuanjie Huang <yuanjie.huang@windriver.com>
> Signed-off-by: Mark Hatle <mark.hatle@windriver.com>
> ---
>  meta/recipes-core/glibc/glibc.inc | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/meta/recipes-core/glibc/glibc.inc b/meta/recipes-core/glibc/glibc.inc
> index e85c7044a0..358e69be67 100644
> --- a/meta/recipes-core/glibc/glibc.inc
> +++ b/meta/recipes-core/glibc/glibc.inc
> @@ -78,3 +78,9 @@ do_configure_prepend() {
>  }
>  
>  GLIBC_ADDONS ?= "nptl,libidn"
> +
> +# Enable backtrace from abort()
> +do_configure_append_arm () {
> +	echo "CFLAGS-abort.c = -funwind-tables" >> ${B}/configparms
> +	echo "CFLAGS-raise.c = -funwind-tables" >> ${B}/configparms
> +}
> 

Re: [PATCH] glibc: Enable backtrace from abort on ARM

[Khem Raj]

On Thu, Dec 8, 2016 at 11:03 AM, Mark Hatle <mark.hatle@windriver.com> wrote:
> +do_configure_append_arm () {
> +       echo "CFLAGS-abort.c = -funwind-tables" >> ${B}/configparms
> +       echo "CFLAGS-raise.c = -funwind-tables" >> ${B}/configparms
> +}

perhaps using  -fasynchronous-unwind-tables is better. can you try that out ?

Re: [PATCH] glibc: Enable backtrace from abort on ARM

[Mark Hatle]

On 12/9/16 12:48 AM, Khem Raj wrote:
> On Thu, Dec 8, 2016 at 11:03 AM, Mark Hatle <mark.hatle@windriver.com> wrote:
>> +do_configure_append_arm () {
>> +       echo "CFLAGS-abort.c = -funwind-tables" >> ${B}/configparms
>> +       echo "CFLAGS-raise.c = -funwind-tables" >> ${B}/configparms
>> +}
> 
> perhaps using  -fasynchronous-unwind-tables is better. can you try that out ?
> 

This passed my internal test with the same results.

So either one is fine with me.  What is the difference between the options?

--Mark

Re: [PATCH] glibc: Enable backtrace from abort on ARM

[Khem Raj]

On Fri, Dec 9, 2016 at 9:26 AM, Mark Hatle <mark.hatle@windriver.com> wrote:
> On 12/9/16 12:48 AM, Khem Raj wrote:
>> On Thu, Dec 8, 2016 at 11:03 AM, Mark Hatle <mark.hatle@windriver.com> wrote:
>>> +do_configure_append_arm () {
>>> +       echo "CFLAGS-abort.c = -funwind-tables" >> ${B}/configparms
>>> +       echo "CFLAGS-raise.c = -funwind-tables" >> ${B}/configparms
>>> +}
>>
>> perhaps using  -fasynchronous-unwind-tables is better. can you try that out ?
>>
>
> This passed my internal test with the same results.
>
> So either one is fine with me.  What is the difference between the options?

-fasynchronous-unwind-tables  when used with -g emits the static data
in dward2 into .debug_frame
sections so your binaries dont bloat. funwind-tables is for generating
static data that is needed  for exception handing into .eh_frame.

>
> --Mark