On 01/05/2018 05:10 PM, Dan Williams wrote:
From: Mark Rutland <mark.rutland@xxxxxxx>
This patch implements nospec_ptr() for arm, following the recommended
architectural sequences for the arm and thumb instruction sets.
Fedora picked up the series and it fails on arm:
In file included from ./include/linux/compiler.h:242:0,
from ./include/uapi/linux/swab.h:6,
from ./include/linux/swab.h:5,
from ./arch/arm/include/asm/opcodes.h:89,
from ./arch/arm/include/asm/bug.h:7,
from ./include/linux/bug.h:5,
from ./include/linux/mmdebug.h:5,
from ./include/linux/gfp.h:5,
from ./include/linux/slab.h:15,
from kernel/fork.c:14:
./include/linux/fdtable.h: In function '__fcheck_files':
./arch/arm/include/asm/barrier.h:112:41: error: expected declaration specifiers or '...' before numeric constant
__load_no_speculate(&__np_ptr, lo, hi, 0, __np_ptr); \
^
./arch/arm/include/asm/barrier.h:68:32: note: in definition of macro '__load_no_speculate_n'
(typeof(*ptr)(unsigned long)(failval)); \
^~~~~~~
./arch/arm/include/asm/barrier.h:112:2: note: in expansion of macro '__load_no_speculate'
__load_no_speculate(&__np_ptr, lo, hi, 0, __np_ptr); \
^~~~~~~~~~~~~~~~~~~
./include/asm-generic/barrier.h:122:2: note: in expansion of macro 'nospec_ptr'
nospec_ptr(__arr + __idx, __arr, __arr + __sz); \
^~~~~~~~~~
./include/linux/fdtable.h:86:13: note: in expansion of macro 'nospec_array_ptr'
if ((fdp = nospec_array_ptr(fdt->fd, fd, fdt->max_fds)))
^~~~~~~~~~~~~~~~
./arch/arm/include/asm/barrier.h:112:41: error: expected declaration specifiers or '...' before numeric constant
__load_no_speculate(&__np_ptr, lo, hi, 0, __np_ptr); \
^
./arch/arm/include/asm/barrier.h:68:32: note: in definition of macro '__load_no_speculate_n'
(typeof(*ptr)(unsigned long)(failval)); \
^~~~~~~
./arch/arm/include/asm/barrier.h:112:2: note: in expansion of macro '__load_no_speculate'
__load_no_speculate(&__np_ptr, lo, hi, 0, __np_ptr); \
^~~~~~~~~~~~~~~~~~~
./include/asm-generic/barrier.h:122:2: note: in expansion of macro 'nospec_ptr'
nospec_ptr(__arr + __idx, __arr, __arr + __sz); \
^~~~~~~~~~
./include/linux/fdtable.h:86:13: note: in expansion of macro 'nospec_array_ptr'
if ((fdp = nospec_array_ptr(fdt->fd, fd, fdt->max_fds)))
^~~~~~~~~~~~~~~~
./arch/arm/include/asm/barrier.h:112:41: error: expected declaration specifiers or '...' before numeric constant
__load_no_speculate(&__np_ptr, lo, hi, 0, __np_ptr); \
^
./arch/arm/include/asm/barrier.h:68:32: note: in definition of macro '__load_no_speculate_n'
(typeof(*ptr)(unsigned long)(failval)); \
^~~~~~~
./arch/arm/include/asm/barrier.h:112:2: note: in expansion of macro '__load_no_speculate'
__load_no_speculate(&__np_ptr, lo, hi, 0, __np_ptr); \
^~~~~~~~~~~~~~~~~~~
./include/asm-generic/barrier.h:122:2: note: in expansion of macro 'nospec_ptr'
nospec_ptr(__arr + __idx, __arr, __arr + __sz); \
^~~~~~~~~~
./include/linux/fdtable.h:86:13: note: in expansion of macro 'nospec_array_ptr'
if ((fdp = nospec_array_ptr(fdt->fd, fd, fdt->max_fds)))
I can't puzzle out what exactly is the problem here, except that it really
does not seem to like that failval. Does the arm compiler not like doing
the typeof with the __arr + __idx?
Thanks,
Laura
Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
arch/arm/include/asm/barrier.h | 75 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 75 insertions(+)
diff --git a/arch/arm/include/asm/barrier.h b/arch/arm/include/asm/barrier.h
index 40f5c410fd8c..6384c90e4b72 100644
--- a/arch/arm/include/asm/barrier.h
+++ b/arch/arm/include/asm/barrier.h
@@ -37,6 +37,81 @@
#define dmb(x) __asm__ __volatile__ ("" : : : "memory")
#endif
+#ifdef CONFIG_THUMB2_KERNEL
+#define __load_no_speculate_n(ptr, lo, hi, failval, cmpptr, sz) \
+({ \
+ typeof(*ptr) __nln_val; \
+ typeof(*ptr) __failval = \
+ (typeof(*ptr)(unsigned long)(failval)); \
+ \
+ asm volatile ( \
+ " cmp %[c], %[l]\n" \
+ " it hs\n" \
+ " cmphs %[h], %[c]\n" \
+ " blo 1f\n" \
+ " ld" #sz " %[v], %[p]\n" \
+ "1: it lo\n" \
+ " movlo %[v], %[f]\n" \
+ " .inst 0xf3af8014 @ CSDB\n" \
+ : [v] "=&r" (__nln_val) \
+ : [p] "m" (*(ptr)), [l] "r" (lo), [h] "r" (hi), \
+ [f] "r" (__failval), [c] "r" (cmpptr) \
+ : "cc"); \
+ \
+ __nln_val; \
+})
+#else
+#define __load_no_speculate_n(ptr, lo, hi, failval, cmpptr, sz) \
+({ \
+ typeof(*ptr) __nln_val; \
+ typeof(*ptr) __failval = \
+ (typeof(*ptr)(unsigned long)(failval)); \
+ \
+ asm volatile ( \
+ " cmp %[c], %[l]\n" \
+ " cmphs %[h], %[c]\n" \
+ " ldr" #sz "hi %[v], %[p]\n" \
+ " movls %[v], %[f]\n" \
+ " .inst 0xe320f014 @ CSDB\n" \
+ : [v] "=&r" (__nln_val) \
+ : [p] "m" (*(ptr)), [l] "r" (lo), [h] "r" (hi), \
+ [f] "r" (__failval), [c] "r" (cmpptr) \
+ : "cc"); \
+ \
+ __nln_val; \
+})
+#endif
+
+#define __load_no_speculate(ptr, lo, hi, failval, cmpptr) \
+({ \
+ typeof(*(ptr)) __nl_val; \
+ \
+ switch (sizeof(__nl_val)) { \
+ case 1: \
+ __nl_val = __load_no_speculate_n(ptr, lo, hi, failval, \
+ cmpptr, b); \
+ break; \
+ case 2: \
+ __nl_val = __load_no_speculate_n(ptr, lo, hi, failval, \
+ cmpptr, h); \
+ break; \
+ case 4: \
+ __nl_val = __load_no_speculate_n(ptr, lo, hi, failval, \
+ cmpptr, ); \
+ break; \
+ default: \
+ BUILD_BUG(); \
+ } \
+ \
+ __nl_val; \
+})
+
+#define nospec_ptr(ptr, lo, hi) \
+({ \
+ typeof(ptr) __np_ptr = (ptr); \
+ __load_no_speculate(&__np_ptr, lo, hi, 0, __np_ptr); \
+})
+
#ifdef CONFIG_ARM_HEAVY_MB
extern void (*soc_mb)(void);
extern void arm_heavy_mb(void);
