diff options
| author | H.J. Lu <hjl.tools@gmail.com> | 2018-06-12 06:23:28 -0700 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2018-06-12 06:34:48 -0700 |
| commit | 0221ce2a90be2d40fc90f0b5dcec77a1ec013f53 (patch) | |
| tree | fbdeebdceffa155aee874f4840861b4e795b810e /sysdeps/i386 | |
| parent | e826574c985a15a500262f2fbd21c7e9259d3d11 (diff) | |
i386: Change offset of __private_ss to 0x30 [BZ #23250]
sysdeps/i386/nptl/tls.h has
typedef struct
{
void *tcb; /* Pointer to the TCB. Not necessarily the
thread descriptor used by libpthread. */
dtv_t *dtv;
void *self; /* Pointer to the thread descriptor. */
int multiple_threads;
uintptr_t sysinfo;
uintptr_t stack_guard;
uintptr_t pointer_guard;
int gscope_flag;
int __glibc_reserved1;
/* Reservation of some values for the TM ABI. */
void *__private_tm[4];
/* GCC split stack support. */
void *__private_ss;
} tcbhead_t;
The offset of __private_ss is 0x34. But GCC defines
/* We steal the last transactional memory word. */
#define TARGET_THREAD_SPLIT_STACK_OFFSET 0x30
and libgcc/config/i386/morestack.S has
cmpl %gs:0x30,%eax # See if we have enough space.
movl %eax,%gs:0x30 # Save the new stack boundary.
movl %eax,%gs:0x30 # Save the new stack boundary.
movl %ecx,%gs:0x30 # Save new stack boundary.
movl %eax,%gs:0x30
movl %gs:0x30,%eax
movl %eax,%gs:0x30
Since update TARGET_THREAD_SPLIT_STACK_OFFSET changes split stack ABI,
this patch updates tcbhead_t to match GCC.
[BZ #23250]
[BZ #10686]
* sysdeps/i386/nptl/tls.h (tcbhead_t): Change __private_tm[4]
to _private_tm[3] and add __glibc_reserved2.
Add _Static_assert of offset of __private_ss == 0x30.
* sysdeps/x86_64/nptl/tls.h: Add _Static_assert of offset of
__private_ss == 0x40 for ILP32 and == 0x70 for LP64.
Diffstat (limited to 'sysdeps/i386')
| -rw-r--r-- | sysdeps/i386/nptl/tls.h | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/sysdeps/i386/nptl/tls.h b/sysdeps/i386/nptl/tls.h index 6c36e58e9c..afb71ce431 100644 --- a/sysdeps/i386/nptl/tls.h +++ b/sysdeps/i386/nptl/tls.h @@ -43,11 +43,16 @@ typedef struct int gscope_flag; int __glibc_reserved1; /* Reservation of some values for the TM ABI. */ - void *__private_tm[4]; + void *__private_tm[3]; /* GCC split stack support. */ void *__private_ss; + void *__glibc_reserved2; } tcbhead_t; +/* morestack.S in libgcc uses offset 0x30 to access __private_ss, */ +_Static_assert (offsetof (tcbhead_t, __private_ss) == 0x30, + "offset of __private_ss != 0x30"); + # define TLS_MULTIPLE_THREADS_IN_TCB 1 #else /* __ASSEMBLER__ */ |