Commit Graph

7 Commits

Author SHA1 Message Date
Fangrui Song fb3c1b3de5 [ELF] Reject local-exec TLS relocations for -shared
For x86-64, D33100 added a diagnostic for local-exec TLS relocations referencing a preemptible symbol.

This patch generalizes it to non-preemptible symbols (see `-Bsymbolic` in `tls.s`)
on all targets.

Local-exec TLS relocations resolve to offsets relative to a fixed point within
the static TLS block, which are only meaningful for the executable.

With this change, `clang -fpic -shared -fuse-ld=bfd a.c` on the following example will be flagged for AArch64/ARM/i386/x86-64/RISC-V

```
static __attribute__((tls_model("local-exec"))) __thread long TlsVar = 42;
long bump() { return ++TlsVar; }
```

Note, in GNU ld, at least arm, riscv and x86's ports have the similar
diagnostics, but aarch64 and ppc64 do not error.

Differential Revision: https://reviews.llvm.org/D93331
2020-12-21 08:47:04 -08:00
Fangrui Song b159906a9a [test] Change llvm-readobj -long-option to --long-option or well-known short options. NFC
Also change some options that have different semantics (cause confusion) in llvm-readelf mode:

-s => -S
-t => --symbols
-sd => --section-data

llvm-svn: 359651
2019-05-01 05:49:01 +00:00
George Rimar ae54e58b90 Recommit r353293 "[LLD][ELF] - Set DF_STATIC_TLS flag for i386 target."
With the following changes:
1) Compilation fix:
std::atomic<bool> HasStaticTlsModel = false; ->
std::atomic<bool> HasStaticTlsModel{false};

2) Adjusted the comment in code.

Initial commit message:

DF_STATIC_TLS flag indicates that the shared object or executable
contains code using a static thread-local storage scheme.

Patch checks if IE/LE relocations were used to check if the code uses
a static model. If so it sets the DF_STATIC_TLS flag.

Differential revision: https://reviews.llvm.org/D57749
----
Modified : /lld/trunk/ELF/Arch/X86.cpp
Modified : /lld/trunk/ELF/Config.h
Modified : /lld/trunk/ELF/SyntheticSections.cpp
Added : /lld/trunk/test/ELF/Inputs/i386-static-tls-model1.s
Added : /lld/trunk/test/ELF/Inputs/i386-static-tls-model2.s
Added : /lld/trunk/test/ELF/Inputs/i386-static-tls-model3.s
Added : /lld/trunk/test/ELF/Inputs/i386-static-tls-model4.s
Added : /lld/trunk/test/ELF/i386-static-tls-model.s
Modified : /lld/trunk/test/ELF/i386-tls-ie-shared.s
Modified : /lld/trunk/test/ELF/tls-dynamic-i686.s
Modified : /lld/trunk/test/ELF/tls-opt-iele-i686-nopic.s

llvm-svn: 353299
2019-02-06 14:43:30 +00:00
George Rimar 52fafcb919 Revert r353293 "[LLD][ELF] - Set DF_STATIC_TLS flag for i386 target."
It broke BB:
http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-ubuntu-fast/builds/43450
http://lab.llvm.org:8011/builders/lld-x86_64-freebsd/builds/27891

Error is:
tools/lld/ELF/Config.h:84:41: error: copying member subobject of type
'std::atomic<bool>' invokes deleted constructor std::atomic<bool> HasStaticTlsModel = false;

llvm-svn: 353297
2019-02-06 13:53:32 +00:00
George Rimar da60ad220b [LLD][ELF] - Set DF_STATIC_TLS flag for i386 target.
DF_STATIC_TLS flag indicates that the shared object or executable
contains code using a static thread-local storage scheme.

Patch checks if IE/LE relocations were used to check if the code uses
a static model. If so it sets the DF_STATIC_TLS flag.

Differential revision: https://reviews.llvm.org/D57749

llvm-svn: 353293
2019-02-06 13:38:10 +00:00
George Rimar b4081bb0ab [ELF] - Stop support of DF_STATIC_TLS flag.
This reverts changes introduced in r302414 "[ELF] - Set DF_STATIC_TLS flag for i386 target."

Because DF_STATIC_TLS does not look to be used by glibc or anything else.

llvm-svn: 302884
2017-05-12 08:04:58 +00:00
George Rimar 1564122b05 [ELF] - Set DF_STATIC_TLS flag for i386 target.
This is PR32437.

DF_STATIC_TLS
If set in a shared object or executable, this flag instructs the 
dynamic linker to reject attempts to load this file dynamically. 
It indicates that the shared object or executable contains code 
using a static thread-local storage scheme. Implementations need 
not support any form of thread-local storage.

Patch checks if IE/LE relocations were used to check if code uses
static model. If so it sets the DF_STATIC_TLS flag.

Differential revision: https://reviews.llvm.org/D32354

llvm-svn: 302414
2017-05-08 10:24:38 +00:00