From: Max Filippov <jcmvbkbc@gmail.com>
To: buildroot@busybox.net
Subject: [Buildroot] [PATCH] gcc: backport xtensa libgcc stack unwinding fixes
Date: Tue, 18 Aug 2015 07:40:38 +0300 [thread overview]
Message-ID: <1439872838-10596-1-git-send-email-jcmvbkbc@gmail.com> (raw)
These backported patches fix the following failing uClibc-ng tests:
nptl/tst-cancelx4,
nptl/tst-cancelx16,
nptl/tst-cancelx18,
nptl/tst-cancelx20,
nptl/tst-cancelx21,
nptl/tst-cleanupx1,
nptl/tst-cleanupx3,
nptl/tst-oncex3,
nptl/tst-oncex4.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
.../871-xtensa-reimplement-register-spilling.patch | 76 ++++++++++++++++++++++
...unwind-dw2-fde-dip-instead-of-unwind-dw2-.patch | 33 ++++++++++
.../gcc/4.8.5/873-xtensa-fix-_Unwind_GetCFA.patch | 40 ++++++++++++
.../871-xtensa-reimplement-register-spilling.patch | 76 ++++++++++++++++++++++
...unwind-dw2-fde-dip-instead-of-unwind-dw2-.patch | 33 ++++++++++
.../gcc/4.9.3/873-xtensa-fix-_Unwind_GetCFA.patch | 40 ++++++++++++
.../871-xtensa-reimplement-register-spilling.patch | 76 ++++++++++++++++++++++
...unwind-dw2-fde-dip-instead-of-unwind-dw2-.patch | 31 +++++++++
.../gcc/5.2.0/873-xtensa-fix-_Unwind_GetCFA.patch | 40 ++++++++++++
9 files changed, 445 insertions(+)
create mode 100644 package/gcc/4.8.5/871-xtensa-reimplement-register-spilling.patch
create mode 100644 package/gcc/4.8.5/872-xtensa-use-unwind-dw2-fde-dip-instead-of-unwind-dw2-.patch
create mode 100644 package/gcc/4.8.5/873-xtensa-fix-_Unwind_GetCFA.patch
create mode 100644 package/gcc/4.9.3/871-xtensa-reimplement-register-spilling.patch
create mode 100644 package/gcc/4.9.3/872-xtensa-use-unwind-dw2-fde-dip-instead-of-unwind-dw2-.patch
create mode 100644 package/gcc/4.9.3/873-xtensa-fix-_Unwind_GetCFA.patch
create mode 100644 package/gcc/5.2.0/871-xtensa-reimplement-register-spilling.patch
create mode 100644 package/gcc/5.2.0/872-xtensa-use-unwind-dw2-fde-dip-instead-of-unwind-dw2-.patch
create mode 100644 package/gcc/5.2.0/873-xtensa-fix-_Unwind_GetCFA.patch
diff --git a/package/gcc/4.8.5/871-xtensa-reimplement-register-spilling.patch b/package/gcc/4.8.5/871-xtensa-reimplement-register-spilling.patch
new file mode 100644
index 0000000..abc7a08
--- /dev/null
+++ b/package/gcc/4.8.5/871-xtensa-reimplement-register-spilling.patch
@@ -0,0 +1,76 @@
+From 05154174b369505238b759cf80d595d8cfc8c731 Mon Sep 17 00:00:00 2001
+From: Max Filippov <jcmvbkbc@gmail.com>
+Date: Mon, 10 Aug 2015 21:35:20 +0300
+Subject: [PATCH 1/3] xtensa: reimplement register spilling
+
+Spilling windowed registers in userspace is much easier, more portable,
+less error-prone and equally effective as in kernel. Now that register
+spilling syscall is considered obsolete in the xtensa linux kernel
+replace it with CALL12 followed by series of ENTRY in libgcc.
+
+2015-08-18 Max Filippov <jcmvbkbc@gmail.com>
+libgcc/
+ * config/xtensa/lib2funcs.S (__xtensa_libgcc_window_spill): Use
+ CALL12 followed by series of ENTRY to spill windowed registers.
+ (__xtensa_nonlocal_goto): Call __xtensa_libgcc_window_spill
+ instead of making linux spill syscall.
+
+Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
+---
+Backported from: r226962
+
+ libgcc/config/xtensa/lib2funcs.S | 30 +++++++++++++++++++++++-------
+ 1 file changed, 23 insertions(+), 7 deletions(-)
+
+diff --git a/libgcc/config/xtensa/lib2funcs.S b/libgcc/config/xtensa/lib2funcs.S
+index 3ac8c1d..2e678af 100644
+--- a/libgcc/config/xtensa/lib2funcs.S
++++ b/libgcc/config/xtensa/lib2funcs.S
+@@ -33,10 +33,29 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+ .global __xtensa_libgcc_window_spill
+ .type __xtensa_libgcc_window_spill, at function
+ __xtensa_libgcc_window_spill:
+- entry sp, 32
+- movi a2, 0
+- syscall
++ entry sp, 48
++#if XCHAL_NUM_AREGS > 16
++ call12 1f
++ retw
++ .align 4
++1:
++ .rept (XCHAL_NUM_AREGS - 24) / 12
++ _entry sp, 48
++ mov a12, a0
++ .endr
++ _entry sp, 16
++#if XCHAL_NUM_AREGS % 12 == 0
++ mov a4, a4
++#elif XCHAL_NUM_AREGS % 12 == 4
++ mov a8, a8
++#elif XCHAL_NUM_AREGS % 12 == 8
++ mov a12, a12
++#endif
++ retw
++#else
++ mov a8, a8
+ retw
++#endif
+ .size __xtensa_libgcc_window_spill, .-__xtensa_libgcc_window_spill
+
+
+@@ -58,10 +77,7 @@ __xtensa_nonlocal_goto:
+ entry sp, 32
+
+ /* Flush registers. */
+- mov a5, a2
+- movi a2, 0
+- syscall
+- mov a2, a5
++ call8 __xtensa_libgcc_window_spill
+
+ /* Because the save area for a0-a3 is stored one frame below
+ the one identified by a2, the only way to restore those
+--
+1.8.1.4
+
diff --git a/package/gcc/4.8.5/872-xtensa-use-unwind-dw2-fde-dip-instead-of-unwind-dw2-.patch b/package/gcc/4.8.5/872-xtensa-use-unwind-dw2-fde-dip-instead-of-unwind-dw2-.patch
new file mode 100644
index 0000000..f23a5c0
--- /dev/null
+++ b/package/gcc/4.8.5/872-xtensa-use-unwind-dw2-fde-dip-instead-of-unwind-dw2-.patch
@@ -0,0 +1,33 @@
+From f66206679a0ad604f13673559f230160cd3d1189 Mon Sep 17 00:00:00 2001
+From: Max Filippov <jcmvbkbc@gmail.com>
+Date: Fri, 14 Aug 2015 02:45:02 +0300
+Subject: [PATCH 2/3] xtensa: use unwind-dw2-fde-dip instead of unwind-dw2-fde
+
+This allows having exception cleanup code in binaries that don't
+register their unwind tables.
+
+2015-08-18 Max Filippov <jcmvbkbc@gmail.com>
+libgcc/
+ * config/xtensa/t-xtensa (LIB2ADDEH): Replace unwind-dw2-fde
+ with unwind-dw2-fde-dip.
+
+Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
+---
+Backported from: r226963
+
+ libgcc/config/xtensa/t-xtensa | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/libgcc/config/xtensa/t-xtensa b/libgcc/config/xtensa/t-xtensa
+index 27399e6..66d0eb3 100644
+--- a/libgcc/config/xtensa/t-xtensa
++++ b/libgcc/config/xtensa/t-xtensa
+@@ -13,4 +13,4 @@ LIB1ASMFUNCS = _mulsi3 _divsi3 _modsi3 _udivsi3 _umodsi3 \
+ LIB2ADD = $(srcdir)/config/xtensa/lib2funcs.S
+
+ LIB2ADDEH = $(srcdir)/config/xtensa/unwind-dw2-xtensa.c \
+- $(srcdir)/unwind-dw2-fde.c $(srcdir)/unwind-sjlj.c $(srcdir)/unwind-c.c
++ $(srcdir)/unwind-dw2-fde-dip.c $(srcdir)/unwind-sjlj.c $(srcdir)/unwind-c.c
+--
+1.8.1.4
+
diff --git a/package/gcc/4.8.5/873-xtensa-fix-_Unwind_GetCFA.patch b/package/gcc/4.8.5/873-xtensa-fix-_Unwind_GetCFA.patch
new file mode 100644
index 0000000..dc40513
--- /dev/null
+++ b/package/gcc/4.8.5/873-xtensa-fix-_Unwind_GetCFA.patch
@@ -0,0 +1,40 @@
+From 15c7c4d39b317f0d902ef28fd43eca5c3369f891 Mon Sep 17 00:00:00 2001
+From: Max Filippov <jcmvbkbc@gmail.com>
+Date: Sat, 15 Aug 2015 05:12:11 +0300
+Subject: [PATCH 3/3] xtensa: fix _Unwind_GetCFA
+
+Returning context->cfa in _Unwind_GetCFA makes CFA point one stack frame
+higher than what was actually used by code at context->ra. This results
+in invalid CFA value in signal frames and premature unwinding completion
+in forced unwinding used by uClibc NPTL thread cancellation.
+Returning context->sp from _Unwind_GetCFA makes all CFA values valid and
+matching code that used them.
+
+2015-08-18 Max Filippov <jcmvbkbc@gmail.com>
+libgcc/
+ * config/xtensa/unwind-dw2-xtensa.c (_Unwind_GetCFA): Return
+ context->sp instead of context->cfa.
+
+Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
+---
+Backported from: r226964
+
+ libgcc/config/xtensa/unwind-dw2-xtensa.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/libgcc/config/xtensa/unwind-dw2-xtensa.c b/libgcc/config/xtensa/unwind-dw2-xtensa.c
+index 35f7797..ef6b900 100644
+--- a/libgcc/config/xtensa/unwind-dw2-xtensa.c
++++ b/libgcc/config/xtensa/unwind-dw2-xtensa.c
+@@ -130,7 +130,7 @@ _Unwind_GetGR (struct _Unwind_Context *context, int index)
+ _Unwind_Word
+ _Unwind_GetCFA (struct _Unwind_Context *context)
+ {
+- return (_Unwind_Ptr) context->cfa;
++ return (_Unwind_Ptr) context->sp;
+ }
+
+ /* Overwrite the saved value for register INDEX in CONTEXT with VAL. */
+--
+1.8.1.4
+
diff --git a/package/gcc/4.9.3/871-xtensa-reimplement-register-spilling.patch b/package/gcc/4.9.3/871-xtensa-reimplement-register-spilling.patch
new file mode 100644
index 0000000..abc7a08
--- /dev/null
+++ b/package/gcc/4.9.3/871-xtensa-reimplement-register-spilling.patch
@@ -0,0 +1,76 @@
+From 05154174b369505238b759cf80d595d8cfc8c731 Mon Sep 17 00:00:00 2001
+From: Max Filippov <jcmvbkbc@gmail.com>
+Date: Mon, 10 Aug 2015 21:35:20 +0300
+Subject: [PATCH 1/3] xtensa: reimplement register spilling
+
+Spilling windowed registers in userspace is much easier, more portable,
+less error-prone and equally effective as in kernel. Now that register
+spilling syscall is considered obsolete in the xtensa linux kernel
+replace it with CALL12 followed by series of ENTRY in libgcc.
+
+2015-08-18 Max Filippov <jcmvbkbc@gmail.com>
+libgcc/
+ * config/xtensa/lib2funcs.S (__xtensa_libgcc_window_spill): Use
+ CALL12 followed by series of ENTRY to spill windowed registers.
+ (__xtensa_nonlocal_goto): Call __xtensa_libgcc_window_spill
+ instead of making linux spill syscall.
+
+Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
+---
+Backported from: r226962
+
+ libgcc/config/xtensa/lib2funcs.S | 30 +++++++++++++++++++++++-------
+ 1 file changed, 23 insertions(+), 7 deletions(-)
+
+diff --git a/libgcc/config/xtensa/lib2funcs.S b/libgcc/config/xtensa/lib2funcs.S
+index 3ac8c1d..2e678af 100644
+--- a/libgcc/config/xtensa/lib2funcs.S
++++ b/libgcc/config/xtensa/lib2funcs.S
+@@ -33,10 +33,29 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+ .global __xtensa_libgcc_window_spill
+ .type __xtensa_libgcc_window_spill, at function
+ __xtensa_libgcc_window_spill:
+- entry sp, 32
+- movi a2, 0
+- syscall
++ entry sp, 48
++#if XCHAL_NUM_AREGS > 16
++ call12 1f
++ retw
++ .align 4
++1:
++ .rept (XCHAL_NUM_AREGS - 24) / 12
++ _entry sp, 48
++ mov a12, a0
++ .endr
++ _entry sp, 16
++#if XCHAL_NUM_AREGS % 12 == 0
++ mov a4, a4
++#elif XCHAL_NUM_AREGS % 12 == 4
++ mov a8, a8
++#elif XCHAL_NUM_AREGS % 12 == 8
++ mov a12, a12
++#endif
++ retw
++#else
++ mov a8, a8
+ retw
++#endif
+ .size __xtensa_libgcc_window_spill, .-__xtensa_libgcc_window_spill
+
+
+@@ -58,10 +77,7 @@ __xtensa_nonlocal_goto:
+ entry sp, 32
+
+ /* Flush registers. */
+- mov a5, a2
+- movi a2, 0
+- syscall
+- mov a2, a5
++ call8 __xtensa_libgcc_window_spill
+
+ /* Because the save area for a0-a3 is stored one frame below
+ the one identified by a2, the only way to restore those
+--
+1.8.1.4
+
diff --git a/package/gcc/4.9.3/872-xtensa-use-unwind-dw2-fde-dip-instead-of-unwind-dw2-.patch b/package/gcc/4.9.3/872-xtensa-use-unwind-dw2-fde-dip-instead-of-unwind-dw2-.patch
new file mode 100644
index 0000000..f23a5c0
--- /dev/null
+++ b/package/gcc/4.9.3/872-xtensa-use-unwind-dw2-fde-dip-instead-of-unwind-dw2-.patch
@@ -0,0 +1,33 @@
+From f66206679a0ad604f13673559f230160cd3d1189 Mon Sep 17 00:00:00 2001
+From: Max Filippov <jcmvbkbc@gmail.com>
+Date: Fri, 14 Aug 2015 02:45:02 +0300
+Subject: [PATCH 2/3] xtensa: use unwind-dw2-fde-dip instead of unwind-dw2-fde
+
+This allows having exception cleanup code in binaries that don't
+register their unwind tables.
+
+2015-08-18 Max Filippov <jcmvbkbc@gmail.com>
+libgcc/
+ * config/xtensa/t-xtensa (LIB2ADDEH): Replace unwind-dw2-fde
+ with unwind-dw2-fde-dip.
+
+Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
+---
+Backported from: r226963
+
+ libgcc/config/xtensa/t-xtensa | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/libgcc/config/xtensa/t-xtensa b/libgcc/config/xtensa/t-xtensa
+index 27399e6..66d0eb3 100644
+--- a/libgcc/config/xtensa/t-xtensa
++++ b/libgcc/config/xtensa/t-xtensa
+@@ -13,4 +13,4 @@ LIB1ASMFUNCS = _mulsi3 _divsi3 _modsi3 _udivsi3 _umodsi3 \
+ LIB2ADD = $(srcdir)/config/xtensa/lib2funcs.S
+
+ LIB2ADDEH = $(srcdir)/config/xtensa/unwind-dw2-xtensa.c \
+- $(srcdir)/unwind-dw2-fde.c $(srcdir)/unwind-sjlj.c $(srcdir)/unwind-c.c
++ $(srcdir)/unwind-dw2-fde-dip.c $(srcdir)/unwind-sjlj.c $(srcdir)/unwind-c.c
+--
+1.8.1.4
+
diff --git a/package/gcc/4.9.3/873-xtensa-fix-_Unwind_GetCFA.patch b/package/gcc/4.9.3/873-xtensa-fix-_Unwind_GetCFA.patch
new file mode 100644
index 0000000..dc40513
--- /dev/null
+++ b/package/gcc/4.9.3/873-xtensa-fix-_Unwind_GetCFA.patch
@@ -0,0 +1,40 @@
+From 15c7c4d39b317f0d902ef28fd43eca5c3369f891 Mon Sep 17 00:00:00 2001
+From: Max Filippov <jcmvbkbc@gmail.com>
+Date: Sat, 15 Aug 2015 05:12:11 +0300
+Subject: [PATCH 3/3] xtensa: fix _Unwind_GetCFA
+
+Returning context->cfa in _Unwind_GetCFA makes CFA point one stack frame
+higher than what was actually used by code at context->ra. This results
+in invalid CFA value in signal frames and premature unwinding completion
+in forced unwinding used by uClibc NPTL thread cancellation.
+Returning context->sp from _Unwind_GetCFA makes all CFA values valid and
+matching code that used them.
+
+2015-08-18 Max Filippov <jcmvbkbc@gmail.com>
+libgcc/
+ * config/xtensa/unwind-dw2-xtensa.c (_Unwind_GetCFA): Return
+ context->sp instead of context->cfa.
+
+Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
+---
+Backported from: r226964
+
+ libgcc/config/xtensa/unwind-dw2-xtensa.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/libgcc/config/xtensa/unwind-dw2-xtensa.c b/libgcc/config/xtensa/unwind-dw2-xtensa.c
+index 35f7797..ef6b900 100644
+--- a/libgcc/config/xtensa/unwind-dw2-xtensa.c
++++ b/libgcc/config/xtensa/unwind-dw2-xtensa.c
+@@ -130,7 +130,7 @@ _Unwind_GetGR (struct _Unwind_Context *context, int index)
+ _Unwind_Word
+ _Unwind_GetCFA (struct _Unwind_Context *context)
+ {
+- return (_Unwind_Ptr) context->cfa;
++ return (_Unwind_Ptr) context->sp;
+ }
+
+ /* Overwrite the saved value for register INDEX in CONTEXT with VAL. */
+--
+1.8.1.4
+
diff --git a/package/gcc/5.2.0/871-xtensa-reimplement-register-spilling.patch b/package/gcc/5.2.0/871-xtensa-reimplement-register-spilling.patch
new file mode 100644
index 0000000..4056f8b
--- /dev/null
+++ b/package/gcc/5.2.0/871-xtensa-reimplement-register-spilling.patch
@@ -0,0 +1,76 @@
+From 40507bf199440082ed69b777986d50c31efe2520 Mon Sep 17 00:00:00 2001
+From: Max Filippov <jcmvbkbc@gmail.com>
+Date: Mon, 10 Aug 2015 21:35:20 +0300
+Subject: [PATCH 1/3] xtensa: reimplement register spilling
+
+Spilling windowed registers in userspace is much easier, more portable,
+less error-prone and equally effective as in kernel. Now that register
+spilling syscall is considered obsolete in the xtensa linux kernel
+replace it with CALL12 followed by series of ENTRY in libgcc.
+
+2015-08-18 Max Filippov <jcmvbkbc@gmail.com>
+libgcc/
+ * config/xtensa/lib2funcs.S (__xtensa_libgcc_window_spill): Use
+ CALL12 followed by series of ENTRY to spill windowed registers.
+ (__xtensa_nonlocal_goto): Call __xtensa_libgcc_window_spill
+ instead of making linux spill syscall.
+
+Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
+---
+Backported from: r226962
+
+ libgcc/config/xtensa/lib2funcs.S | 30 +++++++++++++++++++++++-------
+ 1 file changed, 23 insertions(+), 7 deletions(-)
+
+diff --git a/libgcc/config/xtensa/lib2funcs.S b/libgcc/config/xtensa/lib2funcs.S
+index 4d451c8..ef0703f 100644
+--- a/libgcc/config/xtensa/lib2funcs.S
++++ b/libgcc/config/xtensa/lib2funcs.S
+@@ -34,10 +34,29 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+ .global __xtensa_libgcc_window_spill
+ .type __xtensa_libgcc_window_spill, at function
+ __xtensa_libgcc_window_spill:
+- entry sp, 32
+- movi a2, 0
+- syscall
++ entry sp, 48
++#if XCHAL_NUM_AREGS > 16
++ call12 1f
++ retw
++ .align 4
++1:
++ .rept (XCHAL_NUM_AREGS - 24) / 12
++ _entry sp, 48
++ mov a12, a0
++ .endr
++ _entry sp, 16
++#if XCHAL_NUM_AREGS % 12 == 0
++ mov a4, a4
++#elif XCHAL_NUM_AREGS % 12 == 4
++ mov a8, a8
++#elif XCHAL_NUM_AREGS % 12 == 8
++ mov a12, a12
++#endif
+ retw
++#else
++ mov a8, a8
++ retw
++#endif
+ .size __xtensa_libgcc_window_spill, .-__xtensa_libgcc_window_spill
+ #endif
+
+@@ -61,10 +80,7 @@ __xtensa_nonlocal_goto:
+ entry sp, 32
+
+ /* Flush registers. */
+- mov a5, a2
+- movi a2, 0
+- syscall
+- mov a2, a5
++ call8 __xtensa_libgcc_window_spill
+
+ /* Because the save area for a0-a3 is stored one frame below
+ the one identified by a2, the only way to restore those
+--
+1.8.1.4
+
diff --git a/package/gcc/5.2.0/872-xtensa-use-unwind-dw2-fde-dip-instead-of-unwind-dw2-.patch b/package/gcc/5.2.0/872-xtensa-use-unwind-dw2-fde-dip-instead-of-unwind-dw2-.patch
new file mode 100644
index 0000000..9707f68
--- /dev/null
+++ b/package/gcc/5.2.0/872-xtensa-use-unwind-dw2-fde-dip-instead-of-unwind-dw2-.patch
@@ -0,0 +1,31 @@
+From 7d7a85f75ba218df4a4226e95865fc8fa561cb86 Mon Sep 17 00:00:00 2001
+From: Max Filippov <jcmvbkbc@gmail.com>
+Date: Fri, 14 Aug 2015 02:45:02 +0300
+Subject: [PATCH 2/3] xtensa: use unwind-dw2-fde-dip instead of unwind-dw2-fde
+
+This allows having exception cleanup code in binaries that don't
+register their unwind tables.
+
+2015-08-18 Max Filippov <jcmvbkbc@gmail.com>
+libgcc/
+ * config/xtensa/t-windowed (LIB2ADDEH): Replace unwind-dw2-fde
+ with unwind-dw2-fde-dip.
+
+Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
+---
+Backported from: r226963
+
+ libgcc/config/xtensa/t-windowed | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/libgcc/config/xtensa/t-windowed b/libgcc/config/xtensa/t-windowed
+index 7d9e9db..a99156c 100644
+--- a/libgcc/config/xtensa/t-windowed
++++ b/libgcc/config/xtensa/t-windowed
+@@ -1,2 +1,2 @@
+ LIB2ADDEH = $(srcdir)/config/xtensa/unwind-dw2-xtensa.c \
+- $(srcdir)/unwind-dw2-fde.c $(srcdir)/unwind-sjlj.c $(srcdir)/unwind-c.c
++ $(srcdir)/unwind-dw2-fde-dip.c $(srcdir)/unwind-sjlj.c $(srcdir)/unwind-c.c
+--
+1.8.1.4
+
diff --git a/package/gcc/5.2.0/873-xtensa-fix-_Unwind_GetCFA.patch b/package/gcc/5.2.0/873-xtensa-fix-_Unwind_GetCFA.patch
new file mode 100644
index 0000000..2d8eb7c
--- /dev/null
+++ b/package/gcc/5.2.0/873-xtensa-fix-_Unwind_GetCFA.patch
@@ -0,0 +1,40 @@
+From b33905dc310f475ddbde4c9fb7230724b2068a2b Mon Sep 17 00:00:00 2001
+From: Max Filippov <jcmvbkbc@gmail.com>
+Date: Sat, 15 Aug 2015 05:12:11 +0300
+Subject: [PATCH 3/3] xtensa: fix _Unwind_GetCFA
+
+Returning context->cfa in _Unwind_GetCFA makes CFA point one stack frame
+higher than what was actually used by code at context->ra. This results
+in invalid CFA value in signal frames and premature unwinding completion
+in forced unwinding used by uClibc NPTL thread cancellation.
+Returning context->sp from _Unwind_GetCFA makes all CFA values valid and
+matching code that used them.
+
+2015-08-18 Max Filippov <jcmvbkbc@gmail.com>
+libgcc/
+ * config/xtensa/unwind-dw2-xtensa.c (_Unwind_GetCFA): Return
+ context->sp instead of context->cfa.
+
+Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
+---
+Backported from: r226964
+
+ libgcc/config/xtensa/unwind-dw2-xtensa.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/libgcc/config/xtensa/unwind-dw2-xtensa.c b/libgcc/config/xtensa/unwind-dw2-xtensa.c
+index 82b0e63..8e579c7 100644
+--- a/libgcc/config/xtensa/unwind-dw2-xtensa.c
++++ b/libgcc/config/xtensa/unwind-dw2-xtensa.c
+@@ -130,7 +130,7 @@ _Unwind_GetGR (struct _Unwind_Context *context, int index)
+ _Unwind_Word
+ _Unwind_GetCFA (struct _Unwind_Context *context)
+ {
+- return (_Unwind_Ptr) context->cfa;
++ return (_Unwind_Ptr) context->sp;
+ }
+
+ /* Overwrite the saved value for register INDEX in CONTEXT with VAL. */
+--
+1.8.1.4
+
--
1.8.1.4
next reply other threads:[~2015-08-18 4:40 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-18 4:40 Max Filippov [this message]
2015-09-01 10:46 ` [Buildroot] [PATCH] gcc: backport xtensa libgcc stack unwinding fixes Max Filippov
2015-10-05 15:02 ` Thomas Petazzoni
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