static linking failed with sigaction testing program
This is a follow-up of my previous bug report on static linking failed with
sigaction testing program.
With 0.9.32-rc3, following testing program failed with static linking on MIPS.
The result is same with gcc-4.4.5 and gcc-4.5.2. While my old 0.9.29 uClibc
plus gcc-4.4.5 works well.
Here is static-test.c
#include
int main(void)
{
struct sigaction old, new;
sigaction(11, &new, &old);
return 3;
}
$ mipsel-linux-gcc static-test.c -o static-test -static -lpthread
/big/toolchains/stbgcc-4.5.2-0.2/bin/../mipsel-linux-uclibc/sys-root/usr/lib/libc.a(sigaction.os):
In function `__libc_sigaction':
sigaction.c:(.text+0x0): multiple definition of `__libc_sigaction'
/big/toolchains/stbgcc-4.5.2-0.2/bin/../mipsel-linux-uclibc/sys-root/usr/lib/libpthread.a(pt-sigaction.os):pt-sigaction.c:(.text+0x0):
first defined here
/big/toolchains/stbgcc-4.5.2-0.2/bin/../mipsel-linux-uclibc/sys-root/usr/lib/libc.a(sigaction.os):
In function `sigaction':
sigaction.c:(.text+0x18): multiple definition of `__sigaction'
/big/toolchains/stbgcc-4.5.2-0.2/bin/../mipsel-linux-uclibc/sys-root/usr/lib/libpthread.a(pt-sigaction.os):pt-sigaction.c:(.text+0x18):
first defined here
collect2: ld returned 1 exit status
$ mipsel-linux-gcc static-test.c -o static-test -static -lc -lpthread
has no problem.
The reason is that after sigaction was pulled in from
libpthread.a:pt-sigaction.os, another runtime supporting function abort() in
libc calls sigaction that will be pulled from libc.a:sigaction.os, and cause
multiple definitions.
In case that "-static -lc -lpthread", sigaction was pulled from
libc.a:sigaction.os to resolve undefined sigaction for both the one called in
abort and main already.
To fix it, __libc_sigaction and __sigaction should not be GLOBAL in both libc.a
and libpthread.a.
Here is my patch to fix it.
>From a322d80e01137f8d8287ffda716dbff05960cdab Mon Sep 17 00:00:00 2001
From: Jian Peng
Date: Fri, 25 Mar 2011 16:12:58 -0700
Subject: [PATCH 1/1] MIPS: sigaction static linking failed
With simple sigaction testing program, "mipsel-linux-gcc prog.c -o prog -static
-lpthread" failed to compile due to multiple definition error of
__libc_sigaction and __sigaction.
The problem is that __libc_sigaction and __sigaction should not be GLOBAL in
both libc.a and libpthread.a.
Signed-off-by: Jian Peng
---
libc/sysdeps/linux/mips/sigaction.c | 19 +++
libpthread/nptl/sysdeps/pthread/sigaction.c |3 +--
2 files changed, 16 insertions(+), 6 deletions(-)
diff --git a/libc/sysdeps/linux/mips/sigaction.c
b/libc/sysdeps/linux/mips/sigaction.c
index f2d2747..26b816c 100644
--- a/libc/sysdeps/linux/mips/sigaction.c
+++ b/libc/sysdeps/linux/mips/sigaction.c
@@ -27,8 +27,9 @@
#define SA_RESTORER0x0400
-extern __typeof(sigaction) __libc_sigaction;
-
+#ifdef NOT_IN_libc
+extern __typeof(sigaction) __libc_sigaction;
+#endif
#ifdef __NR_rt_sigaction
@@ -43,7 +44,12 @@ static void restore(void) __asm__ ("__restore");
/* If ACT is not NULL, change the action for SIG to *ACT.
If OACT is not NULL, put the old action for SIG in *OACT. */
-int __libc_sigaction(int sig, const struct sigaction *act, struct sigaction
*oact)
+#ifdef NOT_IN_libc
+int
+#else
+static int
+#endif
+__libc_sigaction(int sig, const struct sigaction *act, struct sigaction *oact)
{
# if _MIPS_SIM != _ABIO32
struct sigaction kact;
@@ -65,7 +71,12 @@ extern void restore(void) __asm__ ("__restore")
attribute_hidden;
/* If ACT is not NULL, change the action for SIG to *ACT.
If OACT is not NULL, put the old action for SIG in *OACT. */
-int __libc_sigaction(int sig, const struct sigaction *act, struct sigaction
*oact)
+#ifdef NOT_IN_libc
+int
+#else
+static int
+#endif
+__libc_sigaction(int sig, const struct sigaction *act, struct sigaction *oact)
{
int result;
struct old_kernel_sigaction kact, koact;
diff --git a/libpthread/nptl/sysdeps/pthread/sigaction.c
b/libpthread/nptl/sysdeps/pthread/sigaction.c
index e004a39..190a3ab 100644
--- a/libpthread/nptl/sysdeps/pthread/sigaction.c
+++ b/libpthread/nptl/sysdeps/pthread/sigaction.c
@@ -26,8 +26,7 @@
#define LIBC_SIGACTION 1
#include
-extern __typeof(sigaction) __sigaction;
-int
+static int
__sigaction (int sig, const struct sigaction *act, struct sigaction *oact)
{
if (__builtin_expect (sig == SIGCANCEL || sig == SIGSETXID, 0))
--
1.7.4.1
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Re: static linking failed with sigaction testing program
Hi
> This is a follow-up of my previous bug report on static linking failed
> with sigaction testing program.
>
> With 0.9.32-rc3, following testing program failed with static linking on
> MIPS. The result is same with gcc-4.4.5 and gcc-4.5.2. While my old 0.9.29
> uClibc plus gcc-4.4.5 works well.
>
>
> Here is static-test.c
>
> #include
>
> int main(void)
> {
> struct sigaction old, new;
>
> sigaction(11, &new, &old);
> return 3;
> }
>
> $ mipsel-linux-gcc static-test.c -o static-test -static -lpthread
>
> /big/toolchains/stbgcc-4.5.2-0.2/bin/../mipsel-linux-uclibc/sys-root/usr/lib/libc.a(sigaction.os):
> In function `__libc_sigaction':
> sigaction.c:(.text+0x0): multiple definition of `__libc_sigaction'
> /big/toolchains/stbgcc-4.5.2-0.2/bin/../mipsel-linux-uclibc/sys-root/usr/lib/libpthread.a(pt-sigaction.os):pt-sigaction.c:(.text+0x0):
>
> first defined here
> /big/toolchains/stbgcc-4.5.2-0.2/bin/../mipsel-linux-uclibc/sys-root/usr/lib/libc.a(sigaction.os):
> In function `sigaction':
> sigaction.c:(.text+0x18): multiple definition of `__sigaction'
it does not really make sense to use -lpthread but that is another story
I assume you are using NPTL as threads, NPTL devs, one of the __sigactions
needs probably be weak
>
> /big/toolchains/stbgcc-4.5.2-0.2/bin/../mipsel-linux-uclibc/sys-root/usr/lib/libpthread.a(pt-sigaction.os):pt-sigaction.c:(.text+0x18):
> first defined here
> collect2: ld returned 1 exit status
>
> $ mipsel-linux-gcc static-test.c -o static-test -static -lc -lpthread
I would say, do not use that syntax, the compiler defaults should be correct
(speak, -lc is added at the end of linking, if any earlier
__sigaction was seen in a library provided on command line by
-l, libc should provide a weak to not conflict
>
> has no problem.
>
> The reason is that after sigaction was pulled in from
> libpthread.a:pt-sigaction.os, another runtime supporting function abort() in
> libc calls
> sigaction that will be pulled from libc.a:sigaction.os, and cause multiple
> definitions.
>
> In case that "-static -lc -lpthread", sigaction was pulled from
> libc.a:sigaction.os to resolve undefined sigaction for both the one called in
> abort
> and main already.
>
> To fix it, __libc_sigaction and __sigaction should not be GLOBAL in both
> libc.a and libpthread.a.
To really fix it, we have to get rid of all duplicated *sigactions, only one
should stay (preferably in libc IMHO)
Peter
>
>
> Here is my patch to fix it.
>
> >From a322d80e01137f8d8287ffda716dbff05960cdab Mon Sep 17 00:00:00 2001
> From: Jian Peng
> Date: Fri, 25 Mar 2011 16:12:58 -0700
>
> Subject: [PATCH 1/1] MIPS: sigaction static linking failed
>
> With simple sigaction testing program, "mipsel-linux-gcc prog.c -o prog
> -static -lpthread" failed to compile due to multiple definition error of
> __libc_sigaction and __sigaction.
>
>
> The problem is that __libc_sigaction and __sigaction should not be GLOBAL
> in both libc.a and libpthread.a.
>
> Signed-off-by: Jian Peng
> ---
>
> libc/sysdeps/linux/mips/sigaction.c | 19 +++
> libpthread/nptl/sysdeps/pthread/sigaction.c |3 +--
> 2 files changed, 16 insertions(+), 6 deletions(-)
>
> diff --git a/libc/sysdeps/linux/mips/sigaction.c
> b/libc/sysdeps/linux/mips/sigaction.c
>
> index f2d2747..26b816c 100644
> --- a/libc/sysdeps/linux/mips/sigaction.c
> +++ b/libc/sysdeps/linux/mips/sigaction.c
> @@ -27,8 +27,9 @@
>
> #define SA_RESTORER 0x0400
>
> -extern __typeof(sigaction) __libc_sigaction;
>
> -
> +#ifdef NOT_IN_libc
> +extern __typeof(sigaction) __libc_sigaction;
> +#endif
>
> #ifdef __NR_rt_sigaction
>
> @@ -43,7 +44,12 @@ static void restore(void) __asm__ ("__restore");
>
> /* If ACT is not NULL, change the action for SIG to *ACT.
>
> If OACT is not NULL, put the old action for SIG in *OACT. */
> -int __libc_sigaction(int sig, const struct sigaction *act, struct
> sigaction *oact)
> +#ifdef NOT_IN_libc
> +int
> +#else
> +static int
> +#endif
>
> +__libc_sigaction(int sig, const struct sigaction *act, struct sigaction
> *oact)
> {
> # if _MIPS_SIM != _ABIO32
> struct sigaction kact;
> @@ -65,7 +71,12 @@ extern void restore(void) __asm__ ("__restore")
> attribute_hidden;
>
>
> /* If ACT is not NULL, change the action for SIG to *ACT.
> If OACT is not NULL, put the old action for SIG in *OACT. */
> -int __libc_sigaction(int sig, const struct sigaction *act, struct
> sigaction *oact)
>
> +#ifdef NOT_IN_libc
> +in
Re: static linking failed with sigaction testing program
On Fri, Mar 25, 2011 at 6:33 PM, Peter Mazinger wrote: > I assume you are using NPTL as threads, NPTL devs, one of the __sigactions > needs probably be weak > I would say, do not use that syntax, the compiler defaults should be correct > (speak, -lc is added at the end of linking, if any earlier > __sigaction was seen in a library provided on command line by > -l, libc should provide a weak to not conflict > To really fix it, we have to get rid of all duplicated *sigactions, only one > should stay (preferably in libc IMHO) Since my glibc-based host PC has no problem compiling the test program regardless of the link order, I checked to see how glibc implements the symbol types: libc.a: sigaction.o: 0220 T __sigaction 0220 W sigaction libpthread.a: sigaction.o: 0220 T __sigaction 0220 W sigaction What is the general consensus on how closely uClibc should try to mirror glibc on these sorts of issues? Is it worth figuring out what they did differently? ___ uClibc mailing list uClibc@uclibc.org http://lists.busybox.net/mailman/listinfo/uclibc
Re: static linking failed with sigaction testing program
On Sat, Mar 26, 2011 at 9:24 PM, Kevin Cernekee wrote: > On Fri, Mar 25, 2011 at 6:33 PM, Peter Mazinger wrote: >> To really fix it, we have to get rid of all duplicated *sigactions, only one >> should stay (preferably in libc IMHO) > > Since my glibc-based host PC has no problem compiling the test program > regardless of the link order, I checked to see how glibc implements > the symbol types: really you should be looking at how the linker processes things. use -Wl,-M for both. -mike ___ uClibc mailing list uClibc@uclibc.org http://lists.busybox.net/mailman/listinfo/uclibc
Re: static linking failed with sigaction testing program
On Sat, Mar 26, 2011 at 10:26 PM, Mike Frysinger wrote: > really you should be looking at how the linker processes things. use > -Wl,-M for both. Thanks for the tip. That is useful. So, for "-static -lpthread -lc" on uClibc: The test program needs sigaction(), and this pulls in libpthread.a(pt-sigaction.os). So far so good. But later on, libc.a(abort.os) needs __GI_sigaction(). This symbol exists in libc.a(sigaction.os) but not in libpthread.a(pt-sigaction.os). So the linker winds up grabbing both .os files. A few strong symbols are duplicated in both libc.a(sigaction.os) and libpthread.a(pt-sigaction.os), which causes the link to fail. For "-static -lpthread -lc" on glibc, there is no __GI_sigaction() to complicate matters. abort() calls __sigaction(). Either libc.a(sigaction.o) or libpthread.a(sigaction.o) can satisfy this dependency, so there is no reason why the linker would ever try to grab both copies of sigaction.o . Interestingly, if I rebuild uClibc with DOPIC disabled, libpthread.a(pt-sigaction.o) now contains __GI_sigaction() and thus the conflict vanishes. I don't know why DOPIC was enabled in the first place, or what else might break due to the change. Time to run some more tests. ___ uClibc mailing list uClibc@uclibc.org http://lists.busybox.net/mailman/listinfo/uclibc
Re: static linking failed with sigaction testing program
My preferance would be to remove the duplicates and implement only one of these functions in libc Peter Original-Nachricht > Datum: Sun, 27 Mar 2011 00:33:20 -0700 > Von: Kevin Cernekee > An: Mike Frysinger > CC: Peter Mazinger , Jian Peng , > uclibc@uclibc.org > Betreff: Re: static linking failed with sigaction testing program > On Sat, Mar 26, 2011 at 10:26 PM, Mike Frysinger > wrote: > > really you should be looking at how the linker processes things. use > > -Wl,-M for both. > > Thanks for the tip. That is useful. > > So, for "-static -lpthread -lc" on uClibc: > > The test program needs sigaction(), and this pulls in > libpthread.a(pt-sigaction.os). So far so good. > > But later on, libc.a(abort.os) needs __GI_sigaction(). This symbol > exists in libc.a(sigaction.os) but not in > libpthread.a(pt-sigaction.os). So the linker winds up grabbing both > .os files. A few strong symbols are duplicated in both > libc.a(sigaction.os) and libpthread.a(pt-sigaction.os), which causes > the link to fail. > > For "-static -lpthread -lc" on glibc, there is no __GI_sigaction() to > complicate matters. abort() calls __sigaction(). Either > libc.a(sigaction.o) or libpthread.a(sigaction.o) can satisfy this > dependency, so there is no reason why the linker would ever try to > grab both copies of sigaction.o . > > Interestingly, if I rebuild uClibc with DOPIC disabled, > libpthread.a(pt-sigaction.o) now contains __GI_sigaction() and thus > the conflict vanishes. > > I don't know why DOPIC was enabled in the first place, or what else > might break due to the change. Time to run some more tests. -- GMX DSL Doppel-Flat ab 19,99 Euro/mtl.! Jetzt mit gratis Handy-Flat! http://portal.gmx.net/de/go/dsl ___ uClibc mailing list uClibc@uclibc.org http://lists.busybox.net/mailman/listinfo/uclibc
