Processed: Re: [klibc] Bug#943425: Debian #943425: klibc: [s390x] setjmp/longjmp do not save/restore all registers in use
Processing commands for cont...@bugs.debian.org: > tags 943425 + patch Bug #943425 [libklibc-dev] klibc: [s390x] setjmp/longjmp do not save/restore all registers in use Added tag(s) patch. > tags 988027 + patch Bug #988027 [libklibc-dev] klibc: sigsetjmp ignores second argument, siglongjmp always restores signals Added tag(s) patch. > thanks Stopping processing here. Please contact me if you need assistance. -- 943425: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=943425 988027: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=988027 Debian Bug Tracking System Contact ow...@bugs.debian.org with problems
Bug#943425: [klibc] Bug#943425: Debian #943425: klibc: [s390x] setjmp/longjmp do not save/restore all registers in use
tags 943425 + patch
tags 988027 + patch
thanks
Dixi quod…
>Patches for klibc upstream git attched; I’m currently trying to test
>them, will report.
This was really tricky given we can’t install patched B-Ds on
porterboxen, but I managed. I can confirm this fixes my issue.
bye,
//mirabilos
--
Beware of ritual lest you forget the meaning behind it.
yeah but it means if you really care about something, don't
ritualise it, or you will lose it. don't fetishise it, don't
obsess. or you'll forget why you love it in the first place.diff -Nru klibc-2.0.8/debian/changelog klibc-2.0.8/debian/changelog
--- klibc-2.0.8/debian/changelog2021-04-30 03:05:23.0 +0200
+++ klibc-2.0.8/debian/changelog2021-05-05 21:38:31.0 +0200
@@ -1,3 +1,11 @@
+klibc (2.0.8-6.1) unstable; urgency=medium
+
+ * Non-maintainer upload.
+ * Fix sig{set,long}jmp always saves the signal mask (Closes: #988027)
+ * [s390x] Fix {set,long}jmp registers to save (Closes: #943425)
+
+ -- Thorsten Glaser Wed, 05 May 2021 21:38:31 +0200
+
klibc (2.0.8-6) unstable; urgency=medium
* Upload to unstable
diff -Nru
klibc-2.0.8/debian/patches/0001-klibc-sig-set-long-jmp-do-not-ignore-sigsetjmp-s-sec.patch
klibc-2.0.8/debian/patches/0001-klibc-sig-set-long-jmp-do-not-ignore-sigsetjmp-s-sec.patch
---
klibc-2.0.8/debian/patches/0001-klibc-sig-set-long-jmp-do-not-ignore-sigsetjmp-s-sec.patch
1970-01-01 01:00:00.0 +0100
+++
klibc-2.0.8/debian/patches/0001-klibc-sig-set-long-jmp-do-not-ignore-sigsetjmp-s-sec.patch
2021-05-05 21:38:31.0 +0200
@@ -0,0 +1,71 @@
+From ba9cce08553cb49fe077485b13ae99548bb2da5c Mon Sep 17 00:00:00 2001
+From: mirabilos
+Date: Wed, 5 May 2021 21:02:37 +0200
+Subject: [PATCH 1/2] [klibc] sig{set,long}jmp: do not ignore sigsetjmp's
+ second argument
+
+Save and restore the signal mask only if that argument is nonzero,
+as required by the standards. (Closes: Debian #988027)
+
+Signed-off-by: mirabilos
+---
+ usr/include/setjmp.h | 7 ++-
+ usr/klibc/CAVEATS | 3 +--
+ usr/klibc/siglongjmp.c | 3 ++-
+ 3 files changed, 9 insertions(+), 4 deletions(-)
+
+diff --git a/usr/include/setjmp.h b/usr/include/setjmp.h
+index abebccde..5916cd8a 100644
+--- a/usr/include/setjmp.h
b/usr/include/setjmp.h
+@@ -27,6 +27,7 @@ __extern __noreturn longjmp(jmp_buf, int);
+ struct __sigjmp_buf {
+ jmp_buf __jmpbuf;
+ sigset_t __sigs;
++ unsigned char __sigs_saved;
+ };
+
+ typedef struct __sigjmp_buf sigjmp_buf[1];
+@@ -34,7 +35,11 @@ typedef struct __sigjmp_buf sigjmp_buf[1];
+ #define sigsetjmp(__env, __save) \
+ ({ \
+ struct __sigjmp_buf *__e = (__env); \
+- sigprocmask(0, NULL, &__e->__sigs); \
++ if (__save) { \
++sigprocmask(0, NULL, &__e->__sigs); \
++__e->__sigs_saved = 1; \
++ } else \
++__e->__sigs_saved = 0; \
+ setjmp(__e->__jmpbuf); \
+ })
+
+diff --git a/usr/klibc/CAVEATS b/usr/klibc/CAVEATS
+index 5e991cb7..39949c28 100644
+--- a/usr/klibc/CAVEATS
b/usr/klibc/CAVEATS
+@@ -13,8 +13,7 @@ Compiling with -O0 is more likely to work on gcc 3.
+ setjmp()/longjmp():
+ ---
+ setjmp() and longjmp() *do not* save signal state. sigsetjmp() and
+-siglongjmp() *do* save the signal mask -- regardless of the value of
+-the extra argument.
++siglongjmp() *do* save the signal mask if the extra argument is nonzero.
+
+ The standards actually state that if you pass longjmp() a final value
+ of zero the library should change that to a 1! Presumably the reason
+diff --git a/usr/klibc/siglongjmp.c b/usr/klibc/siglongjmp.c
+index 31042cbd..45f4e400 100644
+--- a/usr/klibc/siglongjmp.c
b/usr/klibc/siglongjmp.c
+@@ -10,6 +10,7 @@
+
+ __noreturn siglongjmp(sigjmp_buf buf, int retval)
+ {
+- sigprocmask(SIG_SETMASK, >__sigs, NULL);
++ if (buf->__sigs_saved)
++ sigprocmask(SIG_SETMASK, >__sigs, NULL);
+ longjmp(buf->__jmpbuf, retval);
+ }
+--
+2.31.1
+
diff -Nru
klibc-2.0.8/debian/patches/0002-klibc-set-long-jmp-s390x-save-restore-the-correct-re.patch
klibc-2.0.8/debian/patches/0002-klibc-set-long-jmp-s390x-save-restore-the-correct-re.patch
---
klibc-2.0.8/debian/patches/0002-klibc-set-long-jmp-s390x-save-restore-the-correct-re.patch
1970-01-01 01:00:00.0 +0100
+++
klibc-2.0.8/debian/patches/0002-klibc-set-long-jmp-s390x-save-restore-the-correct-re.patch
2021-05-05 21:38:31.0 +0200
@@ -0,0 +1,76 @@
+From fc5a53932ee56d61a9fd8db75784e9f39ca474a3 Mon Sep 17 00:00:00 2001
+From: mirabilos
+Date: Wed, 5 May 2021 21:26:33 +0200
+Subject: [PATCH 2/2] [klibc] {set,long}jmp [s390x]: save/restore the correct
+ registers
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+The s390x ABI actually has FPU registers f8‥f15, not f1/f3/f5/f7,
+to be saved. (Closes: Debian #943425)
+
+Signed-off-by: mirabilos
+---
+ usr/include/arch/s390/klibc/archsetjmp.h | 2 +-
+ usr/klibc/arch/s390/setjmp.S | 24
Bug#985681: linux-cpupower: Fix Pkg Power tracking on Zen
Hi This has now been fixed upstream with https://git.kernel.org/linus/301b1d3a9104f4f3a8ab4171cf88d0f55d632b41 I'm going probably to cherry-pick the commit, but in case you can/want to double check (again I know, but there was some followup) the issue for you that would be great. Regards, Salvatore
Bug#943425: [klibc] Debian #943425: klibc: [s390x] setjmp/longjmp do not save/restore all registers in use
On Wed, 2021-05-05 at 20:24 +0200, Ben Hutchings wrote: > On Wed, 2021-05-05 at 17:32 +, Thorsten Glaser wrote: > [...] > > > > > @klibc list: as indicated earlier, I can provide a patch if needed > > > > > (though it should be obvious). > > > > hpa, maks, bwh: any of you taking these two or should I send patches > > and possibly NMU klibc in Debian? > > Please send patches. If you have a test base that could catch bugs test *case* > like this (without writing lists of registers in the test itself), that > would be really useful. -- Ben Hutchings It is easier to change the specification to fit the program than vice versa. signature.asc Description: This is a digitally signed message part
Processed: found 988027 in 2.0.8-1
Processing commands for cont...@bugs.debian.org: > found 988027 2.0.8-1 Bug #988027 [libklibc-dev] klibc: sigsetjmp ignores second argument, siglongjmp always restores signals Marked as found in versions klibc/2.0.8-1. > thanks Stopping processing here. Please contact me if you need assistance. -- 988027: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=988027 Debian Bug Tracking System Contact ow...@bugs.debian.org with problems
Processed: affects 988027
Processing commands for cont...@bugs.debian.org: > affects 988027 - 2.0.8-1 Bug #988027 [libklibc-dev] klibc: sigsetjmp ignores second argument, siglongjmp always restores signals Removed indication that 988027 affects 2.0.8-1 > thanks Stopping processing here. Please contact me if you need assistance. -- 988027: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=988027 Debian Bug Tracking System Contact ow...@bugs.debian.org with problems
Bug#943425: [klibc] Debian #943425: klibc: [s390x] setjmp/longjmp do not save/restore all registers in use
On Wed, 2021-05-05 at 17:32 +, Thorsten Glaser wrote: [...] > > > > @klibc list: as indicated earlier, I can provide a patch if needed > > > > (though it should be obvious). > > hpa, maks, bwh: any of you taking these two or should I send patches > and possibly NMU klibc in Debian? Please send patches. If you have a test base that could catch bugs like this (without writing lists of registers in the test itself), that would be really useful. Ben. -- Ben Hutchings It is easier to change the specification to fit the program than vice versa. signature.asc Description: This is a digitally signed message part
Processed: affects 988027
Processing commands for cont...@bugs.debian.org: > affects 988027 2.0.8-1 Bug #988027 [libklibc-dev] klibc: sigsetjmp ignores second argument, siglongjmp always restores signals Added indication that 988027 affects 2.0.8-1 > thanks Stopping processing here. Please contact me if you need assistance. -- 988027: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=988027 Debian Bug Tracking System Contact ow...@bugs.debian.org with problems
Bug#943425: Debian #943425: klibc: [s390x] setjmp/longjmp do not save/restore all registers in use
Hi Andreas, >>> Jessica Clarke brought out docs saying f8‥f15 must be saved, the >>> other FPU registers not: > >I can confirm this. It is f8-f15 for the z/Architecture (64 bit). thanks! >It is f1, f3, f5, f7 for the ESA >architecture (32 bit) which is still supported by Glibc and GCC. Is this what we know as s390 in Debian? (klibc saves f4 and f6 there currently. If so, this also needs to change.) >>> … GCC chooses to allocate an FPU register for a pointer value. > >GCC will put integer values into vector registers for >auto-vectorization or for spilling. We also use call-clobbered FPRs as >save slots for GPRs in leaf-functions if can get rid of allocating a >stack frame that way. Ah, interesting. Thanks! >The vector registers are call-clobbered - exactly for the reason of >setjmp / longjmp. Only f8-f15 need to be saved. Right. >You can find the latest version of our ABI here: >https://github.com/IBM/s390x-abi/releases/download/v1.5/lzsabi_s390x.pdf > >However, it is still lacking the vector ABI extension. I wrote a >document for that which we use internally and we are working on >integrating it into the publicly available version. OK, thanks for the information! >>> @klibc list: as indicated earlier, I can provide a patch if needed >>> (though it should be obvious). hpa, maks, bwh: any of you taking these two or should I send patches and possibly NMU klibc in Debian? Thanks, //mirabilos -- you introduced a merge commit│ % g rebase -i HEAD^^ sorry, no idea and rebasing just fscked │ Segmentation should have cloned into a clean repo │ fault (core dumped) if I rebase that now, it's really ugh │ wuahh
Bug#943425: Debian #943425: [s390x] setjmp/longjmp do not save/restore all registers in use
On 5/5/21 4:45 AM, Thorsten Glaser wrote: > Dixi quod… > >> Jessica Clarke brought out docs saying f8‥f15 must be saved, the >> other FPU registers not: I can confirm this. It is f8-f15 for the z/Architecture (64 bit). It is f1, f3, f5, f7 for the ESA architecture (32 bit) which is still supported by Glibc and GCC. > > This needs to be fixed in klibc. > >>> • klibc does not really support the FPU anyway >> >> … GCC chooses to allocate an FPU register for a pointer value. GCC will put integer values into vector registers for auto-vectorization or for spilling. We also use call-clobbered FPRs as save slots for GPRs in leaf-functions if can get rid of allocating a stack frame that way. > > This is a curiosity. > >>> • the half of v10 that equals f10 just HAPPENS to be saved by >>> glibc, but what if the upper half, that is outside of the FPU, >>> is used? >> >> The question here is, does GCC only use the halves of the half >> of the vector registers that match the FPU registers? > > 04:41⎜«jrtc27:#debian-x32» hephaistor: re s390x vector registers, reading the > gcc and llvm sources they're > ⎜all call-clobbered by default, only the float parts are call-saved > 04:41⎜«jrtc27:#debian-x32» so that's why setjmp/longjmp don't need to > save/restore them > 04:42⎜«jrtc27:#debian-x32» there *is* a vector calling convention, but it's > not the default for the ABI, > ⎜it's opt-in, and setjmp/longjmp won't be annotated as such > > So we indeed need to only save the registers glibc does. The vector registers are call-clobbered - exactly for the reason of setjmp / longjmp. Only f8-f15 need to be saved. You can find the latest version of our ABI here: https://github.com/IBM/s390x-abi/releases/download/v1.5/lzsabi_s390x.pdf However, it is still lacking the vector ABI extension. I wrote a document for that which we use internally and we are working on integrating it into the publicly available version. Andreas > >> @klibc list: as indicated earlier, I can provide a patch if needed >> (though it should be obvious). > > bye, > //mirabilos >
