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author | Michael Brown <mcb30@ipxe.org> | 2015-03-04 18:48:19 +0000 |
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committer | Michael Brown <mcb30@ipxe.org> | 2015-03-05 00:59:38 +0000 |
commit | fbc4ba4b4ed13cc86cb8fdea0bac6c3be0164ed5 (patch) | |
tree | a0c504e297806aa88e89a04e694333a7c5172757 /src/net | |
parent | 86ae6e6c1836e43993a14db278398fc54e5419bd (diff) | |
download | ipxe-fbc4ba4b4ed13cc86cb8fdea0bac6c3be0164ed5.zip ipxe-fbc4ba4b4ed13cc86cb8fdea0bac6c3be0164ed5.tar.gz ipxe-fbc4ba4b4ed13cc86cb8fdea0bac6c3be0164ed5.tar.bz2 |
[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 <mcb30@ipxe.org>
Diffstat (limited to 'src/net')
-rw-r--r-- | src/net/80211/net80211.c | 3 | ||||
-rw-r--r-- | src/net/80211/wpa.c | 1 | ||||
-rw-r--r-- | src/net/ethernet.c | 3 | ||||
-rw-r--r-- | src/net/fc.c | 3 | ||||
-rw-r--r-- | src/net/infiniband.c | 3 | ||||
-rw-r--r-- | src/net/ipv4.c | 3 | ||||
-rw-r--r-- | src/net/ipv6.c | 3 |
7 files changed, 19 insertions, 0 deletions
diff --git a/src/net/80211/net80211.c b/src/net/80211/net80211.c index d2051f6..0079459 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 e2c4945..77f66d8 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 ); diff --git a/src/net/ethernet.c b/src/net/ethernet.c index a4bdfd4..33e0572 100644 --- a/src/net/ethernet.c +++ b/src/net/ethernet.c @@ -239,6 +239,9 @@ struct net_device * alloc_etherdev ( size_t priv_size ) { return netdev; } +/* Drag in objects via ethernet_protocol */ +REQUIRING_SYMBOL ( ethernet_protocol ); + /* Drag in Ethernet configuration */ REQUIRE_OBJECT ( config_ethernet ); diff --git a/src/net/fc.c b/src/net/fc.c index 459f6fc..2e80702 100644 --- a/src/net/fc.c +++ b/src/net/fc.c @@ -1940,5 +1940,8 @@ struct fc_ulp * fc_ulp_get_port_id_type ( struct fc_port *port, return NULL; } +/* Drag in objects via fc_ports */ +REQUIRING_SYMBOL ( fc_ports ); + /* Drag in Fibre Channel configuration */ REQUIRE_OBJECT ( config_fc ); diff --git a/src/net/infiniband.c b/src/net/infiniband.c index 7e545f7..8ba031f 100644 --- a/src/net/infiniband.c +++ b/src/net/infiniband.c @@ -999,6 +999,9 @@ struct ib_device * last_opened_ibdev ( void ) { return ibdev; } +/* Drag in objects via register_ibdev() */ +REQUIRING_SYMBOL ( register_ibdev ); + /* Drag in Infiniband configuration */ REQUIRE_OBJECT ( config_infiniband ); diff --git a/src/net/ipv4.c b/src/net/ipv4.c index 85ee5a6..ed22c4d 100644 --- a/src/net/ipv4.c +++ b/src/net/ipv4.c @@ -841,5 +841,8 @@ struct settings_applicator ipv4_settings_applicator __settings_applicator = { .apply = ipv4_create_routes, }; +/* Drag in objects via ipv4_protocol */ +REQUIRING_SYMBOL ( ipv4_protocol ); + /* Drag in ICMPv4 */ REQUIRE_OBJECT ( icmpv4 ); diff --git a/src/net/ipv6.c b/src/net/ipv6.c index 3c37416..c5bead1 100644 --- a/src/net/ipv6.c +++ b/src/net/ipv6.c @@ -1104,6 +1104,9 @@ struct net_driver ipv6_driver __net_driver = { .remove = ipv6_remove, }; +/* Drag in objects via ipv6_protocol */ +REQUIRING_SYMBOL ( ipv6_protocol ); + /* Drag in ICMPv6 */ REQUIRE_OBJECT ( icmpv6 ); |