[PATCH 5.15 70/98] selftests/rseq: Fix ppc32 missing instruction selection "u" and "x" for load/store

Greg Kroah-Hartman
2022-07-05T12:26:19Z

From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

commit de6b52a21420a18dc8a36438d581efd1313d5fe3 upstream.

Building the rseq basic test with
gcc version 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.12)
Target: powerpc-linux-gnu

leads to these errors:

/tmp/ccieEWxU.s: Assembler messages:
/tmp/ccieEWxU.s:118: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:118: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:121: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:121: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:626: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:626: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:629: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:629: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:735: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:735: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:738: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:738: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:741: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:741: Error: junk at end of line: `,8'
Makefile:581: recipe for target 'basic_percpu_ops_test.o' failed

Based on discussion with Linux powerpc maintainers and review of
the use of the "m" operand in powerpc kernel code, add the missing
%Un%Xn (where n is operand number) to the lwz, stw, ld, and std
instructions when used with "m" operands.

Using "WORD" to mean either a 32-bit or 64-bit type depending on
the architecture is misleading. The term "WORD" really means a
32-bit type in both 32-bit and 64-bit powerpc assembler. The intent
here is to wrap load/store to intptr_t into common macros for both
32-bit and 64-bit.

Rename the macros with a RSEQ_ prefix, and use the terms "INT"
for always 32-bit type, and "LONG" for architecture bitness-sized
type.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124171253.22072-10-mathieu.desnoyers@efficios.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
tools/testing/selftests/rseq/rseq-ppc.h | 55 ++++++++++++++++----------------
1 file changed, 28 insertions(+), 27 deletions(-)

--- a/tools/testing/selftests/rseq/rseq-ppc.h
+++ b/tools/testing/selftests/rseq/rseq-ppc.h
@@ -47,10 +47,13 @@ do { \

#ifdef __PPC64__

-#define STORE_WORD "std "
-#define LOAD_WORD "ld "
-#define LOADX_WORD "ldx "
-#define CMP_WORD "cmpd "
+#define RSEQ_STORE_LONG(arg) "std%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] " /* To memory ("m" constraint) */
+#define RSEQ_STORE_INT(arg) "stw%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] " /* To memory ("m" constraint) */
+#define RSEQ_LOAD_LONG(arg) "ld%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] " /* From memory ("m" constraint) */
+#define RSEQ_LOAD_INT(arg) "lwz%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] " /* From memory ("m" constraint) */
+#define RSEQ_LOADX_LONG "ldx " /* From base register ("b" constraint) */
+#define RSEQ_CMP_LONG "cmpd "
+#define RSEQ_CMP_LONG_INT "cmpdi "

#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, \
start_ip, post_commit_offset, abort_ip) \
@@ -89,10 +92,13 @@ do { \

#else /* #ifdef __PPC64__ */

-#define STORE_WORD "stw "
-#define LOAD_WORD "lwz "
-#define LOADX_WORD "lwzx "
-#define CMP_WORD "cmpw "
+#define RSEQ_STORE_LONG(arg) "stw%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] " /* To memory ("m" constraint) */
+#define RSEQ_STORE_INT(arg) RSEQ_STORE_LONG(arg) /* To memory ("m" constraint) */
+#define RSEQ_LOAD_LONG(arg) "lwz%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] " /* From memory ("m" constraint) */
+#define RSEQ_LOAD_INT(arg) RSEQ_LOAD_LONG(arg) /* From memory ("m" constraint) */
+#define RSEQ_LOADX_LONG "lwzx " /* From base register ("b" constraint) */
+#define RSEQ_CMP_LONG "cmpw "
+#define RSEQ_CMP_LONG_INT "cmpwi "

#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, \
start_ip, post_commit_offset, abort_ip) \
@@ -125,7 +131,7 @@ do { \
RSEQ_INJECT_ASM(1) \
"lis %%r17, (" __rseq_str(cs_label) ")@ha\n\t" \
"addi %%r17, %%r17, (" __rseq_str(cs_label) ")@l\n\t" \
- "stw %%r17, %[" __rseq_str(rseq_cs) "]\n\t" \
+ RSEQ_STORE_INT(rseq_cs) "%%r17, %[" __rseq_str(rseq_cs) "]\n\t" \
__rseq_str(label) ":\n\t"

#endif /* #ifdef __PPC64__ */
@@ -136,7 +142,7 @@ do { \

#define RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, label) \
RSEQ_INJECT_ASM(2) \
- "lwz %%r17, %[" __rseq_str(current_cpu_id) "]\n\t" \
+ RSEQ_LOAD_INT(current_cpu_id) "%%r17, %[" __rseq_str(current_cpu_id) "]\n\t" \
"cmpw cr7, %[" __rseq_str(cpu_id) "], %%r17\n\t" \
"bne- cr7, " __rseq_str(label) "\n\t"

@@ -153,25 +159,25 @@ do { \
* RSEQ_ASM_OP_* (else): doesn't have hard-code registers(unless cr7)
*/
#define RSEQ_ASM_OP_CMPEQ(var, expect, label) \
- LOAD_WORD "%%r17, %[" __rseq_str(var) "]\n\t" \
- CMP_WORD "cr7, %%r17, %[" __rseq_str(expect) "]\n\t" \
+ RSEQ_LOAD_LONG(var) "%%r17, %[" __rseq_str(var) "]\n\t" \
+ RSEQ_CMP_LONG "cr7, %%r17, %[" __rseq_str(expect) "]\n\t" \
"bne- cr7, " __rseq_str(label) "\n\t"

#define RSEQ_ASM_OP_CMPNE(var, expectnot, label) \
- LOAD_WORD "%%r17, %[" __rseq_str(var) "]\n\t" \
- CMP_WORD "cr7, %%r17, %[" __rseq_str(expectnot) "]\n\t" \
+ RSEQ_LOAD_LONG(var) "%%r17, %[" __rseq_str(var) "]\n\t" \
+ RSEQ_CMP_LONG "cr7, %%r17, %[" __rseq_str(expectnot) "]\n\t" \
"beq- cr7, " __rseq_str(label) "\n\t"

#define RSEQ_ASM_OP_STORE(value, var) \
- STORE_WORD "%[" __rseq_str(value) "], %[" __rseq_str(var) "]\n\t"
+ RSEQ_STORE_LONG(var) "%[" __rseq_str(value) "], %[" __rseq_str(var) "]\n\t"

/* Load @var to r17 */
#define RSEQ_ASM_OP_R_LOAD(var) \
- LOAD_WORD "%%r17, %[" __rseq_str(var) "]\n\t"
+ RSEQ_LOAD_LONG(var) "%%r17, %[" __rseq_str(var) "]\n\t"

/* Store r17 to @var */
#define RSEQ_ASM_OP_R_STORE(var) \
- STORE_WORD "%%r17, %[" __rseq_str(var) "]\n\t"
+ RSEQ_STORE_LONG(var) "%%r17, %[" __rseq_str(var) "]\n\t"

/* Add @count to r17 */
#define RSEQ_ASM_OP_R_ADD(count) \
@@ -179,11 +185,11 @@ do { \

/* Load (r17 + voffp) to r17 */
#define RSEQ_ASM_OP_R_LOADX(voffp) \
- LOADX_WORD "%%r17, %[" __rseq_str(voffp) "], %%r17\n\t"
+ RSEQ_LOADX_LONG "%%r17, %[" __rseq_str(voffp) "], %%r17\n\t"

/* TODO: implement a faster memcpy. */
#define RSEQ_ASM_OP_R_MEMCPY() \
- "cmpdi %%r19, 0\n\t" \
+ RSEQ_CMP_LONG_INT "%%r19, 0\n\t" \
"beq 333f\n\t" \
"addi %%r20, %%r20, -1\n\t" \
"addi %%r21, %%r21, -1\n\t" \
@@ -191,16 +197,16 @@ do { \
"lbzu %%r18, 1(%%r20)\n\t" \
"stbu %%r18, 1(%%r21)\n\t" \
"addi %%r19, %%r19, -1\n\t" \
- "cmpdi %%r19, 0\n\t" \
+ RSEQ_CMP_LONG_INT "%%r19, 0\n\t" \
"bne 222b\n\t" \
"333:\n\t" \

#define RSEQ_ASM_OP_R_FINAL_STORE(var, post_commit_label) \
- STORE_WORD "%%r17, %[" __rseq_str(var) "]\n\t" \
+ RSEQ_STORE_LONG(var) "%%r17, %[" __rseq_str(var) "]\n\t" \
__rseq_str(post_commit_label) ":\n\t"

#define RSEQ_ASM_OP_FINAL_STORE(value, var, post_commit_label) \
- STORE_WORD "%[" __rseq_str(value) "], %[" __rseq_str(var) "]\n\t" \
+ RSEQ_STORE_LONG(var) "%[" __rseq_str(value) "], %[" __rseq_str(var) "]\n\t" \
__rseq_str(post_commit_label) ":\n\t"

static inline __attribute__((always_inline))
@@ -743,9 +749,4 @@ error2:
#endif
}

-#undef STORE_WORD
-#undef LOAD_WORD
-#undef LOADX_WORD
-#undef CMP_WORD
-
#endif /* !RSEQ_SKIP_FASTPATH */