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| author | Clément Chigot <clement.chigot@atos.net> | 2021-08-12 13:17:15 -0400 |
|---|---|---|
| committer | David Edelsohn <dje.gcc@gmail.com> | 2021-08-15 13:26:27 -0400 |
| commit | 34ce7f7a9a64dd69dd6a77dfd4a77406c3c71014 (patch) | |
| tree | 693b86639899af4c92e6b5c28062f734a47e23a8 | |
| parent | 882f1d58bfa56737ff2de84c3cd1e0acfc318b86 (diff) | |
| download | gcc-34ce7f7a9a64dd69dd6a77dfd4a77406c3c71014.zip gcc-34ce7f7a9a64dd69dd6a77dfd4a77406c3c71014.tar.gz gcc-34ce7f7a9a64dd69dd6a77dfd4a77406c3c71014.tar.bz2 | |
aix: 64 bit AIX TLS libpthread dependency.
64bit XCOFF files will generated TLS access, with local-exec or
global-exec models, by an access to R13. Thus, there isn't
any reference to a TLS symbol.
The problem is that it allows programs with TLS to be compiled and
linked even without -pthread. Most of the time, it will result in
a segfault when trying to access a TLS variable. But sometimes, it
might create a memory corruption.
This patch forces a reference to __tls_get_addr() to ensure link
will fail without -pthread.
gcc/ChangeLog:
2021-08-11 Clément Chigot <clement.chigot@atos.net>
* config/rs6000/rs6000.c (xcoff_tls_exec_model_detected): New.
(rs6000_legitimize_tls_address_aix): Use it.
(rs6000_xcoff_file_end): Add ".ref __tls_get_addr" when
xcoff_tls_exec_model_detected is true.
| -rw-r--r-- | gcc/config/rs6000/rs6000.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c index 60f406a..e073b26 100644 --- a/gcc/config/rs6000/rs6000.c +++ b/gcc/config/rs6000/rs6000.c @@ -127,6 +127,9 @@ scalar_int_mode rs6000_pmode; bool rs6000_passes_ieee128 = false; #endif +/* Track use of r13 in 64bit AIX TLS. */ +static bool xcoff_tls_exec_model_detected = false; + /* Generate the manged name (i.e. U10__float128) used in GCC 8.1, and not the name used in current releases (i.e. u9__ieee128). */ static bool ieee128_mangling_gcc_8_1; @@ -9397,7 +9400,10 @@ rs6000_legitimize_tls_address_aix (rtx addr, enum tls_model model) emit_insn (gen_tls_get_tpointer (tlsreg)); } else - tlsreg = gen_rtx_REG (DImode, 13); + { + tlsreg = gen_rtx_REG (DImode, 13); + xcoff_tls_exec_model_detected = true; + } /* Load the TOC value into temporary register. */ tmpreg = gen_reg_rtx (Pmode); @@ -21122,6 +21128,12 @@ rs6000_xcoff_file_end (void) fputs (TARGET_32BIT ? "\t.long _section_.text\n" : "\t.llong _section_.text\n", asm_out_file); + + if (xcoff_tls_exec_model_detected) + { + /* Add a .ref to __tls_get_addr to force libpthread dependency. */ + fputs ("\t.extern __tls_get_addr\n\t.ref __tls_get_addr\n", asm_out_file); + } } struct declare_alias_data |