| Message ID | 20230911205741.2139309-1-ben.wolsieffer@hefring.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [uclibc-ng-devel] fork: fix stub on no-MMU systems | expand |
Hi Ben, can you explain what this patch is fixing exactly? Is it a runtime or compile time bug going away with this patch? I thought fork() is not supported, but clone() is. best regards Waldemar Ben Wolsieffer wrote, > From: Ben Wolsieffer <Ben.Wolsieffer@hefring.com> > > The stub code undefs __NR_fork on no-MMU systems, but it also needs to > undef __NR_clone since fork can now be implemented using clone, and > clone is not available either on no-MMU systems. > --- > libc/sysdeps/linux/common/stubs.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/libc/sysdeps/linux/common/stubs.c b/libc/sysdeps/linux/common/stubs.c > index c17e509b9..11849e3ba 100644 > --- a/libc/sysdeps/linux/common/stubs.c > +++ b/libc/sysdeps/linux/common/stubs.c > @@ -36,6 +36,7 @@ __attribute_used__ static int ret_enosys_stub(void) > > #ifndef __ARCH_USE_MMU__ > # undef __NR_fork > +# undef __NR_clone > #endif > > #ifdef __arm__ > -- > 2.42.0 > > _______________________________________________ > devel mailing list -- devel@uclibc-ng.org > To unsubscribe send an email to devel-leave@uclibc-ng.org >
Hi Waldemar, > Hi Ben, > > can you explain what this patch is fixing exactly? > Is it a runtime or compile time bug going away with this patch? The bug is that on no-MMU ARM with stubs enabled, there is no fork() stub (and of course no real implementation of fork()). > I thought fork() is not supported, but clone() is. Yes, you are right. What I should have said is that clone() cannot be used to implement fork() on no-MMU. That does perhaps imply that the correct way to fix this bug is to add !__ARCH_USE_MMU__ to the condition that enables the fork() stub, rather than undefining __NR_clone. Thanks, Ben > Ben Wolsieffer wrote, > > > From: Ben Wolsieffer <Ben.Wolsieffer@hefring.com> > > > > The stub code undefs __NR_fork on no-MMU systems, but it also needs to > > undef __NR_clone since fork can now be implemented using clone, and > > clone is not available either on no-MMU systems. > > --- > > libc/sysdeps/linux/common/stubs.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/libc/sysdeps/linux/common/stubs.c b/libc/sysdeps/linux/common/stubs.c > > index c17e509b9..11849e3ba 100644 > > --- a/libc/sysdeps/linux/common/stubs.c > > +++ b/libc/sysdeps/linux/common/stubs.c > > @@ -36,6 +36,7 @@ __attribute_used__ static int ret_enosys_stub(void) > > > > #ifndef __ARCH_USE_MMU__ > > # undef __NR_fork > > +# undef __NR_clone > > #endif > > > > #ifdef __arm__ > > -- > > 2.42.0 > > > > _______________________________________________ > > devel mailing list -- devel@uclibc-ng.org > > To unsubscribe send an email to devel-leave@uclibc-ng.org > >
diff --git a/libc/sysdeps/linux/common/stubs.c b/libc/sysdeps/linux/common/stubs.c index c17e509b9..11849e3ba 100644 --- a/libc/sysdeps/linux/common/stubs.c +++ b/libc/sysdeps/linux/common/stubs.c @@ -36,6 +36,7 @@ __attribute_used__ static int ret_enosys_stub(void) #ifndef __ARCH_USE_MMU__ # undef __NR_fork +# undef __NR_clone #endif #ifdef __arm__
From: Ben Wolsieffer <Ben.Wolsieffer@hefring.com> The stub code undefs __NR_fork on no-MMU systems, but it also needs to undef __NR_clone since fork can now be implemented using clone, and clone is not available either on no-MMU systems. --- libc/sysdeps/linux/common/stubs.c | 1 + 1 file changed, 1 insertion(+)