diff options
| author | Stefan Agner <stefan@agner.ch> | 2019-03-23 12:09:49 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@armlinux.org.uk> | 2019-04-23 17:20:51 +0100 |
| commit | a6c9e96bf86b8aa86d8696b7887e52c2e95bac0f (patch) | |
| tree | 64ab02244f143452b8bc8e6a1ca61264feac1181 /arch/arm/include/asm/futex.h | |
| parent | 9e98c678c2d6ae3a17cb2de55d17f69dddaa231b (diff) | |
ARM: 8851/1: add TUSERCOND() macro for conditional postfix
Unified assembly syntax requires conditionals to be postfixes.
TUSER() currently only takes a single argument which then gets
appended t (with translation) on every instruction.
This fixes a build error when using LLVM's integrated assembler:
In file included from kernel/futex.c:72:
./arch/arm/include/asm/futex.h:116:3: error: invalid instruction, did you mean: strt?
"2: " TUSER(streq) " %3, [%4]n"
^
<inline asm>:5:4: note: instantiated into assembly here
2: streqt r2, [r4]
^~~~~~
Additionally, for GCC ".syntax unified" for inline assembly.
When compiling non-Thumb2 GCC always emits a ".syntax divided"
at the beginning of the inline assembly which makes the
assembler fail. Since GCC 5 there is the -masm-syntax-unified
GCC option which make GCC assume unified syntax asm and hence
emits ".syntax unified" even in ARM mode. However, the option
is broken since GCC version 6 (see GCC PR88648 [1]). Work
around by adding ".syntax unified" as part of the inline
assembly.
[0] https://gcc.gnu.org/onlinedocs/gcc/ARM-Options.html#index-masm-syntax-unified
[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88648
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch/arm/include/asm/futex.h')
| -rw-r--r-- | arch/arm/include/asm/futex.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/arm/include/asm/futex.h b/arch/arm/include/asm/futex.h index 0a46676b4245..83c391b597d4 100644 --- a/arch/arm/include/asm/futex.h +++ b/arch/arm/include/asm/futex.h @@ -110,10 +110,11 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, preempt_disable(); __ua_flags = uaccess_save_and_enable(); __asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n" + " .syntax unified\n" "1: " TUSER(ldr) " %1, [%4]\n" " teq %1, %2\n" " it eq @ explicit IT needed for the 2b label\n" - "2: " TUSER(streq) " %3, [%4]\n" + "2: " TUSERCOND(str, eq) " %3, [%4]\n" __futex_atomic_ex_table("%5") : "+r" (ret), "=&r" (val) : "r" (oldval), "r" (newval), "r" (uaddr), "Ir" (-EFAULT) |