On Thu, Oct 21, 2021 at 4:06 PM Christian Göttsche <cgzones@xxxxxxxxxxxxxx> wrote: > > Glibc 2.34 added an access function attribute to pthread_setspecific(3). > This leads to the following GCC warnings: > > In file included from matchpathcon.c:5: > matchpathcon.c: In function ‘matchpathcon_init_prefix’: > selinux_internal.h:38:25: error: ‘pthread_setspecific’ expecting 1 byte in a region of size 0 [-Werror=stringop-overread] > 38 | pthread_setspecific(KEY, VALUE); \ > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > matchpathcon.c:359:9: note: in expansion of macro ‘__selinux_setspecific’ > 359 | __selinux_setspecific(destructor_key, (void *)1); > | ^~~~~~~~~~~~~~~~~~~~~ > In file included from selinux_internal.h:2, > from matchpathcon.c:5: > /usr/include/pthread.h:1167:12: note: in a call to function ‘pthread_setspecific’ declared with attribute ‘access (none, 2)’ > 1167 | extern int pthread_setspecific (pthread_key_t __key, > | ^~~~~~~~~~~~~~~~~~~ > > The actual value and the validity of the passed pointer is irrelevant, > since it does not gets accessed internally by glibc and > pthread_getspecific(3) is not used. > Use a pointer to a global object to please GCC. > > Closes: https://github.com/SELinuxProject/selinux/issues/311 > Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx> Acked-by: Nicolas Iooss <nicolas.iooss@xxxxxxx> Sorry for the delay, I have been busy with other topics. Thanks! Nicolas > --- > libselinux/src/matchpathcon.c | 2 +- > libselinux/src/procattr.c | 2 +- > libselinux/src/setrans_client.c | 2 +- > 3 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/libselinux/src/matchpathcon.c b/libselinux/src/matchpathcon.c > index 1e7f8890..ea78a23e 100644 > --- a/libselinux/src/matchpathcon.c > +++ b/libselinux/src/matchpathcon.c > @@ -356,7 +356,7 @@ int matchpathcon_init_prefix(const char *path, const char *subset) > mycanoncon = default_canoncon; > > __selinux_once(once, matchpathcon_init_once); > - __selinux_setspecific(destructor_key, (void *)1); > + __selinux_setspecific(destructor_key, /* some valid address to please GCC */ &selinux_page_size); > > options[SELABEL_OPT_SUBSET].type = SELABEL_OPT_SUBSET; > options[SELABEL_OPT_SUBSET].value = subset; > diff --git a/libselinux/src/procattr.c b/libselinux/src/procattr.c > index 6552ee01..142fbf3a 100644 > --- a/libselinux/src/procattr.c > +++ b/libselinux/src/procattr.c > @@ -68,7 +68,7 @@ void __attribute__((destructor)) procattr_destructor(void) > static inline void init_thread_destructor(void) > { > if (destructor_initialized == 0) { > - __selinux_setspecific(destructor_key, (void *)1); > + __selinux_setspecific(destructor_key, /* some valid address to please GCC */ &selinux_page_size); > destructor_initialized = 1; > } > } > diff --git a/libselinux/src/setrans_client.c b/libselinux/src/setrans_client.c > index 52a8ba78..faa12681 100644 > --- a/libselinux/src/setrans_client.c > +++ b/libselinux/src/setrans_client.c > @@ -272,7 +272,7 @@ static inline void init_thread_destructor(void) > if (!has_setrans) > return; > if (destructor_initialized == 0) { > - __selinux_setspecific(destructor_key, (void *)1); > + __selinux_setspecific(destructor_key, /* some valid address to please GCC */ &selinux_page_size); > destructor_initialized = 1; > } > } > -- > 2.33.0 >
