From fbc4ba4b4ed13cc86cb8fdea0bac6c3be0164ed5 Mon Sep 17 00:00:00 2001 From: Michael Brown Date: Wed, 4 Mar 2015 18:48:19 +0000 Subject: [build] Fix the REQUIRE_SYMBOL mechanism At some point in the past few years, binutils became more aggressive at removing unused symbols. To function as a symbol requirement, a relocation record must now be in a section marked with @progbits and must not be in a section which gets discarded during the link (either via --gc-sections or via /DISCARD/). Update REQUIRE_SYMBOL() to generate relocation records meeting these criteria. To minimise the impact upon the final binary size, we use existing symbols (specified via the REQUIRING_SYMBOL() macro) as the relocation targets where possible. We use R_386_NONE or R_X86_64_NONE relocation types to prevent any actual unwanted relocation taking place. Where no suitable symbol exists for REQUIRING_SYMBOL() (such as in config.c), the macro PROVIDE_REQUIRING_SYMBOL() can be used to generate a one-byte-long symbol to act as the relocation target. If there are versions of binutils for which this approach fails, then the fallback will probably involve killing off REQUEST_SYMBOL(), redefining REQUIRE_SYMBOL() to use the current definition of REQUEST_SYMBOL(), and postprocessing the linked ELF file with something along the lines of "nm -u | wc -l" to check that there are no undefined symbols remaining. Signed-off-by: Michael Brown --- src/net/80211/net80211.c | 3 +++ src/net/80211/wpa.c | 1 + 2 files changed, 4 insertions(+) (limited to 'src/net/80211') diff --git a/src/net/80211/net80211.c b/src/net/80211/net80211.c index d2051f642..00794592e 100644 --- a/src/net/80211/net80211.c +++ b/src/net/80211/net80211.c @@ -2827,5 +2827,8 @@ struct errortab common_wireless_errors[] __errortab = { __einfo_errortab ( EINFO_ECONNREFUSED_AUTH_ALGO_UNSUPP ), }; +/* Drag in objects via net80211_ll_protocol */ +REQUIRING_SYMBOL ( net80211_ll_protocol ); + /* Drag in 802.11 configuration */ REQUIRE_OBJECT ( config_net80211 ); diff --git a/src/net/80211/wpa.c b/src/net/80211/wpa.c index e2c4945f9..77f66d825 100644 --- a/src/net/80211/wpa.c +++ b/src/net/80211/wpa.c @@ -912,4 +912,5 @@ struct eapol_handler eapol_key_handler __eapol_handler = { }; /* WPA always needs EAPOL in order to be useful */ +REQUIRING_SYMBOL ( eapol_key_handler ); REQUIRE_OBJECT ( eapol ); -- cgit v1.2.3-55-g7522