diff mbox series

[2/2] AARCH64: Turn off unwind tables for crtbeginT.o

Message ID 20230723010645.1622083-2-apinski@marvell.com
State Accepted
Headers
Series [1/2] Fix PR 110066: crash with -pg -static on riscv |

Checks

Context Check Description
snail/gcc-patch-check success Github commit url

Commit Message

Andrew Pinski July 23, 2023, 1:06 a.m. UTC 
  The problem -fasynchronous-unwind-tables is on by default for aarch64
We need turn it off for crt*.o because it would make __EH_FRAME_BEGIN__ point
to .eh_frame data from crtbeginT.o instead of the user-defined object
during static linking.

This turns it off.

OK? Bootstrapped and tested on aarch64-linux-gnu with no regressions.

libgcc/ChangeLog:

	* config.host (aarch64*-*-*): Add t-crtstuff to tmake_file.
	* config/aarch64/t-crtstuff: New file.
---
 libgcc/config.host               | 6 ++++++
 libgcc/config/aarch64/t-crtstuff | 5 +++++
 2 files changed, 11 insertions(+)
 create mode 100644 libgcc/config/aarch64/t-crtstuff

Comments

Richard Sandiford July 24, 2023, 3:55 p.m. UTC | #1 
Andrew Pinski via Gcc-patches <gcc-patches@gcc.gnu.org> writes:
> The problem -fasynchronous-unwind-tables is on by default for aarch64
> We need turn it off for crt*.o because it would make __EH_FRAME_BEGIN__ point
> to .eh_frame data from crtbeginT.o instead of the user-defined object
> during static linking.

Could you go into more details?  Which user-defined object do you mean?

I notice alpha has:

    # When GAS-generated unwind tables are created, they get created
    # after the __FRAME_END__ terminator, which causes an ld error.
    CRTSTUFF_T_CFLAGS = -fno-unwind-tables

which I guess was a separate problem.

Thanks,
Richard
Richard Biener July 25, 2023, 7:06 a.m. UTC | #2 
On Mon, Jul 24, 2023 at 5:56 PM Richard Sandiford via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> Andrew Pinski via Gcc-patches <gcc-patches@gcc.gnu.org> writes:
> > The problem -fasynchronous-unwind-tables is on by default for aarch64
> > We need turn it off for crt*.o because it would make __EH_FRAME_BEGIN__ point
> > to .eh_frame data from crtbeginT.o instead of the user-defined object
> > during static linking.
>
> Could you go into more details?  Which user-defined object do you mean?
>
> I notice alpha has:
>
>     # When GAS-generated unwind tables are created, they get created
>     # after the __FRAME_END__ terminator, which causes an ld error.
>     CRTSTUFF_T_CFLAGS = -fno-unwind-tables
>
> which I guess was a separate problem.

x86 has

# crtend*.o cannot be compiled without -fno-asynchronous-unwind-tables,
# because then __FRAME_END__ might not be the last thing in .eh_frame
# section.

>
> Thanks,
> Richard
diff mbox series

Patch

diff --git a/libgcc/config.host b/libgcc/config.host
index c94d69d84b7..b2d82041a69 100644
--- a/libgcc/config.host
+++ b/libgcc/config.host
@@ -390,6 +390,7 @@  aarch64*-*-elf | aarch64*-*-rtems*)
 	extra_parts="$extra_parts crtbegin.o crtend.o crti.o crtn.o"
 	extra_parts="$extra_parts crtfastmath.o"
 	tmake_file="${tmake_file} ${cpu_type}/t-aarch64"
+	tmake_file="${tmake_file} ${cpu_type}/t-crtstuff"
 	tmake_file="${tmake_file} ${cpu_type}/t-lse t-slibgcc-libgcc"
 	tmake_file="${tmake_file} ${cpu_type}/t-softfp t-softfp t-crtfm"
 	tmake_file="${tmake_file} t-dfprules"
@@ -398,6 +399,7 @@  aarch64*-*-elf | aarch64*-*-rtems*)
 aarch64*-*-freebsd*)
 	extra_parts="$extra_parts crtfastmath.o"
 	tmake_file="${tmake_file} ${cpu_type}/t-aarch64"
+	tmake_file="${tmake_file} ${cpu_type}/t-crtstuff"
 	tmake_file="${tmake_file} ${cpu_type}/t-lse t-slibgcc-libgcc"
 	tmake_file="${tmake_file} ${cpu_type}/t-softfp t-softfp t-crtfm"
 	tmake_file="${tmake_file} t-dfprules"
@@ -406,12 +408,14 @@  aarch64*-*-freebsd*)
 aarch64*-*-netbsd*)
 	extra_parts="$extra_parts crtfastmath.o"
 	tmake_file="${tmake_file} ${cpu_type}/t-aarch64"
+	tmake_file="${tmake_file} ${cpu_type}/t-crtstuff"
 	tmake_file="${tmake_file} ${cpu_type}/t-softfp t-softfp t-crtfm"
 	tmake_file="${tmake_file} t-dfprules"
 	md_unwind_header=aarch64/aarch64-unwind.h
 	;;
 aarch64*-*-fuchsia*)
 	tmake_file="${tmake_file} ${cpu_type}/t-aarch64"
+	tmake_file="${tmake_file} ${cpu_type}/t-crtstuff"
 	tmake_file="${tmake_file} ${cpu_type}/t-lse t-slibgcc-libgcc"
 	tmake_file="${tmake_file} ${cpu_type}/t-softfp t-softfp"
 	tmake_file="${tmake_file} t-dfprules"
@@ -420,6 +424,7 @@  aarch64*-*-linux*)
 	extra_parts="$extra_parts crtfastmath.o"
 	md_unwind_header=aarch64/linux-unwind.h
 	tmake_file="${tmake_file} ${cpu_type}/t-aarch64"
+	tmake_file="${tmake_file} ${cpu_type}/t-crtstuff"
 	tmake_file="${tmake_file} ${cpu_type}/t-lse t-slibgcc-libgcc"
 	tmake_file="${tmake_file} ${cpu_type}/t-softfp t-softfp t-crtfm"
 	tmake_file="${tmake_file} t-dfprules"
@@ -428,6 +433,7 @@  aarch64*-*-vxworks7*)
 	extra_parts="$extra_parts crtfastmath.o"
 	md_unwind_header=aarch64/aarch64-unwind.h
 	tmake_file="${tmake_file} ${cpu_type}/t-aarch64"
+	tmake_file="${tmake_file} ${cpu_type}/t-crtstuff"
 	tmake_file="${tmake_file} ${cpu_type}/t-lse"
 	tmake_file="${tmake_file} ${cpu_type}/t-softfp t-softfp t-crtfm"
 	tmake_file="${tmake_file} t-dfprules"
diff --git a/libgcc/config/aarch64/t-crtstuff b/libgcc/config/aarch64/t-crtstuff
new file mode 100644
index 00000000000..2e2814e6c67
--- /dev/null
+++ b/libgcc/config/aarch64/t-crtstuff
@@ -0,0 +1,5 @@ 
+# -fasynchronous-unwind-tables -funwind-tables is on by default for aarch64
+# We turn it off for crt*.o because it would make __EH_FRAME_BEGIN__ point
+# to .eh_frame data from crtbeginT.o instead of the user-defined object
+# during static linking.
+CRTSTUFF_T_CFLAGS += -fno-asynchronous-unwind-tables -fno-unwind-tables