From 88677348b4de73874ca7d5a47451f42880f65f07 Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Netto Date: Tue, 27 Dec 2022 18:11:42 -0300 Subject: Move libc_freeres_ptrs and libc_subfreeres to hidden/weak functions They are both used by __libc_freeres to free all library malloc allocated resources to help tooling like mtrace or valgrind with memory leak tracking. The current scheme uses assembly markers and linker script entries to consolidate the free routine function pointers in the RELRO segment and to be freed buffers in BSS. This patch changes it to use specific free functions for libc_freeres_ptrs buffers and call the function pointer array directly with call_function_static_weak. It allows the removal of both the internal macros and the linker script sections. Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu. Reviewed-by: Carlos O'Donell --- resolv/gai_misc.c | 6 +++++- resolv/res-close.c | 2 -- resolv/res_hconf.c | 16 +++------------- resolv/resolv-internal.h | 14 ++++++++++++++ resolv/resolv_conf.c | 3 ++- resolv/tst-leaks2.c | 2 ++ 6 files changed, 26 insertions(+), 17 deletions(-) (limited to 'resolv') diff --git a/resolv/gai_misc.c b/resolv/gai_misc.c index dda9b47f00..9e3b1d29b7 100644 --- a/resolv/gai_misc.c +++ b/resolv/gai_misc.c @@ -434,7 +434,11 @@ handle_requests (void *arg) /* Free allocated resources. */ -libc_freeres_fn (free_res) +#if !PTHREAD_IN_LIBC +__attribute__ ((__destructor__)) static +#endif +void +__gai_freemem (void) { size_t row; diff --git a/resolv/res-close.c b/resolv/res-close.c index 936fd3d1dd..8d546777c7 100644 --- a/resolv/res-close.c +++ b/resolv/res-close.c @@ -140,5 +140,3 @@ __res_thread_freeres (void) /* Make sure we do a full re-initialization the next time. */ _res.options = 0; } -/* Also must be called when the main thread exits. */ -text_set_element (__libc_subfreeres, __res_thread_freeres); diff --git a/resolv/res_hconf.c b/resolv/res_hconf.c index 2c4e12b6cd..89bd20be38 100644 --- a/resolv/res_hconf.c +++ b/resolv/res_hconf.c @@ -42,6 +42,7 @@ #include "res_hconf.h" #include #include +#include #if IS_IN (libc) # define fgets_unlocked __fgets_unlocked @@ -330,19 +331,8 @@ _res_hconf_init (void) #if IS_IN (libc) # if defined SIOCGIFCONF && defined SIOCGIFNETMASK /* List of known interfaces. */ -libc_freeres_ptr ( -static struct netaddr -{ - int addrtype; - union - { - struct - { - uint32_t addr; - uint32_t mask; - } ipv4; - } u; -} *ifaddrs); +static struct netaddr *ifaddrs; +weak_alias (ifaddrs, __libc_resolv_res_hconf_freemem_ptr) # endif /* Reorder addresses returned in a hostent such that the first address diff --git a/resolv/resolv-internal.h b/resolv/resolv-internal.h index 97812ebf6c..c55f3c0366 100644 --- a/resolv/resolv-internal.h +++ b/resolv/resolv-internal.h @@ -34,6 +34,20 @@ loads and stores. */ typedef HEADER __attribute__ ((__aligned__(1))) UHEADER; +/* List of known interfaces. */ +struct netaddr +{ + int addrtype; + union + { + struct + { + uint32_t addr; + uint32_t mask; + } ipv4; + } u; +}; + /* Legacy function. This needs to be removed once all NSS modules have been adjusted. */ static inline bool diff --git a/resolv/resolv_conf.c b/resolv/resolv_conf.c index 2e561c8959..0ef66d49d3 100644 --- a/resolv/resolv_conf.c +++ b/resolv/resolv_conf.c @@ -654,7 +654,8 @@ __resolv_conf_detach (struct __res_state *resp) } /* Deallocate the global data. */ -libc_freeres_fn (freeres) +void +__libc_resolv_conf_freemem (void) { /* No locking because this function is supposed to be called when the process has turned single-threaded. */ diff --git a/resolv/tst-leaks2.c b/resolv/tst-leaks2.c index 3851ea06ce..50a8054546 100644 --- a/resolv/tst-leaks2.c +++ b/resolv/tst-leaks2.c @@ -23,6 +23,8 @@ #include #include +void __libc_freeres (void); + static int do_test (void) { -- cgit 1.4.1