On Tue, 3 Nov 2009 10:06:17 +0000
Alan Jenkins <alan-jenkins@xxxxxxxxxxxxxx> wrote:
modpost of vmlinux.o now extracts the ksymtab sections and outputs
sorted versions of them as .tmp_exports-asm.S. These sorted sections
are linked into vmlinux and the original unsorted sections are
discarded.
This will allow modules to be loaded faster, resolving symbols using
binary search, without any increase in the memory needed for the
symbol tables.
This does not affect the building of modules, so hopefully it won't
affect compile times too much.
Minimally tested on ARM under QEMU emulator.
Build tested on blackfin; output of "size -A" unchanged.
I'm getting a segfault from write_exports().
(gdb) bt
#0 0x0000003e5f075510 in strlen () from /lib64/libc.so.6
#1 0x0000003e5f045cb8 in vfprintf () from /lib64/libc.so.6
#2 0x0000003e5f06683a in vsnprintf () from /lib64/libc.so.6
#3 0x0000000000401897 in buf_printf (buf=0x7fff5514f5e0, fmt=0x7fff5514f4e0 "0x%02x ") at scripts/mod/modpost.c:1692
#4 0x00000000004042c8 in main (argc=1024, argv=0x7fff5514f5e0)
at scripts/mod/modpost.c:2063
(gdb) f 4
#4 0x00000000004042c8 in main (argc=1024, argv=0x7fff5514f5e0)
at scripts/mod/modpost.c:2063
2063 buf_printf(&buf, "__EXPORT_%s_SYMBOL(%s,"
(gdb) p sym
$1 = (struct symbol *) 0x65c9f0
(gdb) p *sym
$2 = {next = 0x64c3a0, module = 0x610010, crc = 4077789248, crc_valid = 1, weak = 0, vmlinux = 0, kernel = 0, preloaded = 0, function = 1, export = export_unknown, name = 0x65ca10 "simple_prepare_write"}
(gdb) p sym->export
$3 = export_unknown
(gdb) p/d sym->export
$4 = 5
but section_names[] (which could be static in write_exports() btw) has
only five entries.