bionic: Add crt_pad_segment
crt_pad_segment provides a note of type NT_ANDROID_TYPE_PAD_SEGMENT.
It's intended when present is for the loader to pad segment gaps to
reduce kernel slab memory usage (due to additional vm_area_struct's
for gaps). crt_pad_segment.o retains control to the static linker so
that app developers can opt out (build with different flags) it there
are undesireable side effects.
Section Headers:
[Nr] Name Type Address Off Size ES Flg Lk Inf Al
[ 0] NULL 0000000000000000 000000 000000 00 0 0 0
[ 1] .strtab STRTAB 0000000000000000 0000f8 000066 00 0 0 1
[ 2] .text PROGBITS 0000000000000000 000040 000000 00 AX 0 0 4
[ 3] .note.GNU-stack PROGBITS 0000000000000000 000040 000000 00 0 0 1
[ 4] .note.android.pad_segment NOTE 0000000000000000 000040 00001c 00 A 0 0 4
[ 5] .rela.note.android.pad_segment RELA 0000000000000000 0000e0 000018 18 I 7 4 8
[ 6] .debug_line PROGBITS 0000000000000000 00005c 000052 00 0 0 1
[ 7] .symtab SYMTAB 0000000000000000 0000b0 000030 18 1 1 8
Key to Flags:
W (write), A (alloc), X (execute), M (merge), S (strings), I (info),
L (link order), O (extra OS processing required), G (group), T (TLS),
C (compressed), x (unknown), o (OS specific), E (exclude),
D (mbind), l (large), p (processor specific)
Bug: 316403210
Test: m -j50 ndk
Test: find out/soong/ndk -name 'crt_pad_segment.o'
Test: readelf -SW crt_pag_segment.o
Change-Id: I94af5e85fd602e7ba5fd56788ae39277368229d8
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
diff --git a/libc/Android.bp b/libc/Android.bp
index fdf34eb..139fd0e 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -2319,6 +2319,17 @@
defaults: ["crt_defaults"],
}
+cc_object {
+ name: "crt_pad_segment",
+ local_include_dirs: [
+ "include",
+ "private", // crt_pad_segment.S depends on private/bionic_asm_note.h
+ ],
+ srcs: ["arch-common/bionic/crt_pad_segment.S"],
+
+ defaults: ["crt_defaults"],
+}
+
cc_library_static {
name: "note_memtag_heap_async",
arch: {