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| author | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2020-06-10 13:40:40 +0100 |
|---|---|---|
| committer | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2020-07-08 17:32:56 +0100 |
| commit | ffb17e7ba3a5ba9632cee97330b325072fbe41dd (patch) | |
| tree | bf6865a3ec36c6a818a73bee954b06568154a90f /elf/Makefile | |
| parent | 17796419b5fd694348cceb65c3f77601faae082c (diff) | |
| download | glibc-ffb17e7ba3a5ba9632cee97330b325072fbe41dd.tar glibc-ffb17e7ba3a5ba9632cee97330b325072fbe41dd.tar.gz glibc-ffb17e7ba3a5ba9632cee97330b325072fbe41dd.tar.bz2 glibc-ffb17e7ba3a5ba9632cee97330b325072fbe41dd.zip | |
rtld: Avoid using up static TLS surplus for optimizations [BZ #25051]
On some targets static TLS surplus area can be used opportunistically
for dynamically loaded modules such that the TLS access then becomes
faster (TLSDESC and powerpc TLS optimization). However we don't want
all surplus TLS to be used for this optimization because dynamically
loaded modules with initial-exec model TLS can only use surplus TLS.
The new contract for surplus static TLS use is:
- libc.so can have up to 192 bytes of IE TLS,
- other system libraries together can have up to 144 bytes of IE TLS.
- Some "optional" static TLS is available for opportunistic use.
The optional TLS is now tunable: rtld.optional_static_tls, so users
can directly affect the allocated static TLS size. (Note that module
unloading with dlclose does not reclaim static TLS. After the optional
TLS runs out, TLS access is no longer optimized to use static TLS.)
The default setting of rtld.optional_static_tls is 512 so the surplus
TLS is 3*192 + 4*144 + 512 = 1664 by default, the same as before.
Fixes BZ #25051.
Tested on aarch64-linux-gnu and x86_64-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Diffstat (limited to 'elf/Makefile')
| -rw-r--r-- | elf/Makefile | 29 |
1 files changed, 27 insertions, 2 deletions
diff --git a/elf/Makefile b/elf/Makefile index 81a696c3ef..a2c3b12007 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -209,7 +209,8 @@ tests += restest1 preloadtest loadfail multiload origtest resolvfail \ tst-dlopenfail-2 \ tst-filterobj tst-filterobj-dlopen tst-auxobj tst-auxobj-dlopen \ tst-audit14 tst-audit15 tst-audit16 \ - tst-single_threaded tst-single_threaded-pthread + tst-single_threaded tst-single_threaded-pthread \ + tst-tls-ie tst-tls-ie-dlmopen # reldep9 tests-internal += loadtest unload unload2 circleload1 \ neededtest neededtest2 neededtest3 neededtest4 \ @@ -324,7 +325,11 @@ modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \ tst-filterobj-flt tst-filterobj-aux tst-filterobj-filtee \ tst-auditlogmod-1 tst-auditlogmod-2 tst-auditlogmod-3 \ tst-single_threaded-mod1 tst-single_threaded-mod2 \ - tst-single_threaded-mod3 tst-single_threaded-mod4 + tst-single_threaded-mod3 tst-single_threaded-mod4 \ + tst-tls-ie-mod0 tst-tls-ie-mod1 tst-tls-ie-mod2 \ + tst-tls-ie-mod3 tst-tls-ie-mod4 tst-tls-ie-mod5 \ + tst-tls-ie-mod6 + # Most modules build with _ISOMAC defined, but those filtered out # depend on internal headers. modules-names-tests = $(filter-out ifuncmod% tst-libc_dlvsym-dso tst-tlsmod%,\ @@ -1769,3 +1774,23 @@ $(objpfx)tst-single_threaded-pthread.out: \ $(objpfx)tst-single_threaded-mod2.so $(objpfx)tst-single_threaded-mod3.so \ $(objpfx)tst-single_threaded-mod4.so $(objpfx)tst-single_threaded-pthread-static: $(static-thread-library) + +$(objpfx)tst-tls-ie: $(libdl) $(shared-thread-library) +$(objpfx)tst-tls-ie.out: \ + $(objpfx)tst-tls-ie-mod0.so \ + $(objpfx)tst-tls-ie-mod1.so \ + $(objpfx)tst-tls-ie-mod2.so \ + $(objpfx)tst-tls-ie-mod3.so \ + $(objpfx)tst-tls-ie-mod4.so \ + $(objpfx)tst-tls-ie-mod5.so \ + $(objpfx)tst-tls-ie-mod6.so + +$(objpfx)tst-tls-ie-dlmopen: $(libdl) $(shared-thread-library) +$(objpfx)tst-tls-ie-dlmopen.out: \ + $(objpfx)tst-tls-ie-mod0.so \ + $(objpfx)tst-tls-ie-mod1.so \ + $(objpfx)tst-tls-ie-mod2.so \ + $(objpfx)tst-tls-ie-mod3.so \ + $(objpfx)tst-tls-ie-mod4.so \ + $(objpfx)tst-tls-ie-mod5.so \ + $(objpfx)tst-tls-ie-mod6.so |