[Bug target/58066] GCC mis-compiles access to TLS variable with -fPIC on x86_64
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58066 --- Comment #8 from Dmitry Vyukov --- Is there any progress on this? Is it fixed? I've hit this issue in ThreadSanitizer. It intercepts __tls_get_addr and then code that uses MOVDQA [rbp] crashes. I remember that I hit it previously in some other context as well.
[Bug target/58066] GCC mis-compiles access to TLS variable with -fPIC on x86_64
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58066 --- Comment #7 from wmi at gcc dot gnu.org --- Author: wmi Date: Mon May 19 05:25:45 2014 New Revision: 210601 URL: http://gcc.gnu.org/viewcvs?rev=210601&root=gcc&view=rev Log: 2014-05-18 Wei Mi PR target/58066 * gcc.target/i386/pr58066.c: Replace pattern matching of .cfi directive with rtl insns. Add effective-target of fpic and tls_native. Modified: trunk/gcc/testsuite/ChangeLog trunk/gcc/testsuite/gcc.target/i386/pr58066.c
[Bug target/58066] GCC mis-compiles access to TLS variable with -fPIC on x86_64
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58066 --- Comment #6 from wmi at gcc dot gnu.org --- Author: wmi Date: Thu May 8 16:44:52 2014 New Revision: 210222 URL: http://gcc.gnu.org/viewcvs?rev=210222&root=gcc&view=rev Log: gcc/ 2014-05-08 Wei Mi PR target/58066 * config/i386/i386.c (ix86_compute_frame_layout): Update preferred_stack_boundary for call, expanded from tls descriptor. * config/i386/i386.md: (*tls_global_dynamic_32_gnu): Update RTX to depend on SP register. (*tls_local_dynamic_base_32_gnu): Ditto. (*tls_local_dynamic_32_once): Ditto. (tls_global_dynamic_64_): Set ix86_tls_descriptor_calls_expanded_in_cfun. (tls_local_dynamic_base_64_): Ditto. (tls_global_dynamic_32): Set ix86_tls_descriptor_calls_expanded_in_cfun. Update RTX to depend on SP register. (tls_local_dynamic_base_32): Ditto. gcc/testsuite/ 2014-05-08 Wei Mi PR target/58066 * gcc.target/i386/pr58066.c: New test. Added: trunk/gcc/testsuite/gcc.target/i386/pr58066.c Modified: trunk/gcc/ChangeLog trunk/gcc/config/i386/i386.c trunk/gcc/config/i386/i386.md trunk/gcc/testsuite/ChangeLog
[Bug target/58066] GCC mis-compiles access to TLS variable with -fPIC on x86_64
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58066
--- Comment #5 from H.J. Lu ---
Another problem:
[hjl@gnu-6 gcc]$ cat /tmp/c.i
static __thread char ccc;
void* __cxa_get_globals()
{
return &ccc;
}
[hjl@gnu-6 gcc]$ ./xgcc -B./ -S -O2 -fPIC /tmp/c.i
[hjl@gnu-6 gcc]$ cat /tmp/c.i
static __thread char ccc;
void* __cxa_get_globals()
{
return &ccc;
}
[hjl@gnu-6 gcc]$ ./xgcc -B./ -S -O2 -fPIC /tmp/c.i -m32
[hjl@gnu-6 gcc]$ cat c.s
.file"c.i"
.section.text.unlikely,"ax",@progbits
.LCOLDB0:
.text
.LHOTB0:
.p2align 4,,15
.globl__cxa_get_globals
.type__cxa_get_globals, @function
__cxa_get_globals:
.LFB0:
.cfi_startproc
pushl%ebx
.cfi_def_cfa_offset 8
.cfi_offset 3, -8
call__x86.get_pc_thunk.bx
addl$_GLOBAL_OFFSET_TABLE_, %ebx
subl$8, %esp
.cfi_def_cfa_offset 16
addl$8, %esp
.cfi_def_cfa_offset 8
lealccc@tlsgd(,%ebx,1), %eax
call___tls_get_addr@PLT
popl%ebx
.cfi_restore 3
.cfi_def_cfa_offset 4
ret
.cfi_endproc
.LFE0:
.size__cxa_get_globals, .-__cxa_get_globals
sched2 doesn't know
(insn:TI 15 25 13 2 (parallel [
(set (reg:SI 0 ax [86])
(unspec:SI [
(reg:SI 3 bx)
(symbol_ref:SI ("ccc") [flags 0x1a] )
(symbol_ref:SI ("___tls_get_addr"))
] UNSPEC_TLS_GD))
(clobber (reg:SI 1 dx [88]))
(clobber (reg:SI 2 cx [89]))
(clobber (reg:CC 17 flags))
]) /tmp/c.i:5 772 {*tls_global_dynamic_32_gnu}
(expr_list:REG_DEAD (reg:SI 3 bx)
(expr_list:REG_UNUSED (reg:CC 17 flags)
(expr_list:REG_UNUSED (reg:SI 2 cx [89])
(expr_list:REG_UNUSED (reg:SI 1 dx [88])
(expr_list:REG_EQUIV (unspec:SI [
(reg:SI 3 bx)
(symbol_ref:SI ("ccc") [flags 0x1a] )
(symbol_ref:SI ("___tls_get_addr"))
] UNSPEC_TLS_GD)
(nil)))
is a function call and move stack adjustment cross it.
[Bug target/58066] GCC mis-compiles access to TLS variable with -fPIC on x86_64
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58066 --- Comment #4 from H.J. Lu --- Created attachment 32341 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=32341&action=edit A patch This patch sets ix86_tls_descriptor_calls_expanded_in_cfun after reload is complete and checks it for stack boundary in ix86_frame_pointer_required.
[Bug target/58066] GCC mis-compiles access to TLS variable with -fPIC on x86_64
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58066 --- Comment #3 from Paul Pluzhnikov --- (In reply to Paul Pluzhnikov from comment #2) > What is the way to turn it on? Compiling test case with -mtls-dialect=gnu2 does appear to improve the picture: g++ -fPIC -O2 -S t.cc -mtls-dialect=gnu2 __cxa_get_globals: leaq_ZL3ccc@TLSDESC(%rip), %rax call*_ZL3ccc@TLSCALL(%rax) addq%fs:0, %rax ret The indirect call goes to _dl_tlsdesc_dynamic in ld-linux-x86-64.so.2 with misaligned stack, and the latter re-aligns it.
[Bug target/58066] GCC mis-compiles access to TLS variable with -fPIC on x86_64
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58066 --- Comment #2 from Paul Pluzhnikov --- (In reply to Andrew Pinski from comment #1) > Which most Linux distro default to anyways ... Ubuntu 12.04.1 LTS doesn't. Configuring trunk GCC on it doesn't default to GNU2 TLS either. What is the way to turn it on?
[Bug target/58066] GCC mis-compiles access to TLS variable with -fPIC on x86_64
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58066 Andrew Pinski changed: What|Removed |Added Component|c |target --- Comment #1 from Andrew Pinski --- > However, it appears to have only been fully implemented for the GNU2 TLS > descriptor style ... Which most Linux distro default to anyways ...
