diff options
| -rw-r--r-- | ChangeLog | 7 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/arm/atomic-machine.h | 18 |
2 files changed, 20 insertions, 5 deletions
@@ -1,3 +1,10 @@ +2019-01-02 Aurelien Jarno <aurelien@aurel32.net> + + [BZ #24034] + * sysdeps/unix/sysv/linux/arm/atomic-machine.h + (__arm_assisted_compare_and_exchange_val_32_acq): Use uint32_t rather + than __typeof (...) for the a_ptr variable. + 2019-01-02 Gabriel F. T. Gomes <gabriel@inconstante.eti.br> * debug/sprintf_chk.c (___sprintf_chk): Use PRINTF_CHK. diff --git a/sysdeps/unix/sysv/linux/arm/atomic-machine.h b/sysdeps/unix/sysv/linux/arm/atomic-machine.h index e94a1bb6c0..5bc3b6540d 100644 --- a/sysdeps/unix/sysv/linux/arm/atomic-machine.h +++ b/sysdeps/unix/sysv/linux/arm/atomic-machine.h @@ -49,16 +49,23 @@ declarations of A_OLDVAL et al because when NEWVAL or OLDVAL is of the form *PTR and PTR has a 'volatile ... *' type, then __typeof (*PTR) has a 'volatile ...' type and this triggers -Wvolatile-register-var to - complain about 'register volatile ... asm ("reg")'. */ + complain about 'register volatile ... asm ("reg")'. + + We use the same union trick in the declaration of A_PTR because when + MEM is of the from *PTR and PTR has a 'const ... *' type, then __typeof + (*PTR) has a 'const ...' type and this enables the compiler to substitute + the variable with its initializer in asm statements, which may cause the + corresponding operand to appear in a different register. */ #ifdef __thumb2__ /* Thumb-2 has ldrex/strex. However it does not have barrier instructions, so we still need to use the kernel helper. */ # define __arm_assisted_compare_and_exchange_val_32_acq(mem, newval, oldval) \ - ({ union { __typeof (oldval) a; uint32_t v; } oldval_arg = { .a = (oldval) };\ + ({ union { __typeof (mem) a; uint32_t v; } mem_arg = { .a = (mem) }; \ + union { __typeof (oldval) a; uint32_t v; } oldval_arg = { .a = (oldval) };\ union { __typeof (newval) a; uint32_t v; } newval_arg = { .a = (newval) };\ register uint32_t a_oldval asm ("r0"); \ register uint32_t a_newval asm ("r1") = newval_arg.v; \ - register __typeof (mem) a_ptr asm ("r2") = (mem); \ + register uint32_t a_ptr asm ("r2") = mem_arg.v; \ register uint32_t a_tmp asm ("r3"); \ register uint32_t a_oldval2 asm ("r4") = oldval_arg.v; \ __asm__ __volatile__ \ @@ -79,11 +86,12 @@ (__typeof (oldval)) a_tmp; }) #else # define __arm_assisted_compare_and_exchange_val_32_acq(mem, newval, oldval) \ - ({ union { __typeof (oldval) a; uint32_t v; } oldval_arg = { .a = (oldval) };\ + ({ union { __typeof (mem) a; uint32_t v; } mem_arg = { .a = (mem) }; \ + union { __typeof (oldval) a; uint32_t v; } oldval_arg = { .a = (oldval) };\ union { __typeof (newval) a; uint32_t v; } newval_arg = { .a = (newval) };\ register uint32_t a_oldval asm ("r0"); \ register uint32_t a_newval asm ("r1") = newval_arg.v; \ - register __typeof (mem) a_ptr asm ("r2") = (mem); \ + register uint32_t a_ptr asm ("r2") = mem_arg.v; \ register uint32_t a_tmp asm ("r3"); \ register uint32_t a_oldval2 asm ("r4") = oldval_arg.v; \ __asm__ __volatile__ \ |