selftests/rseq: Change type of rseq_offset to ptrdiff_t

Just before the 2.35 release of glibc, the __rseq_offset userspace ABI
was changed from int to ptrdiff_t.

Adapt to this change in the kernel selftests.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://sourceware.org/pipermail/libc-alpha/2022-February/136024.html

tools/testing/selftests/rseq/rseq-x86.h

@@ -143,7 +143,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_offset]		"r" ((long)rseq_offset),
+		  [rseq_offset]		"r" (rseq_offset),
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -214,7 +214,7 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_offset]		"r" ((long)rseq_offset),
+		  [rseq_offset]		"r" (rseq_offset),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expectnot]		"r" (expectnot),
@@ -270,7 +270,7 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_offset]		"r" ((long)rseq_offset),
+		  [rseq_offset]		"r" (rseq_offset),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [count]		"er" (count)
@@ -329,7 +329,7 @@ int rseq_offset_deref_addv(intptr_t *ptr, long off, intptr_t inc, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_offset]		"r" ((long)rseq_offset),
+		  [rseq_offset]		"r" (rseq_offset),
 		  /* final store input */
 		  [ptr]			"m" (*ptr),
 		  [off]			"er" (off),
@@ -387,7 +387,7 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_offset]		"r" ((long)rseq_offset),
+		  [rseq_offset]		"r" (rseq_offset),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -469,7 +469,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_offset]		"r" ((long)rseq_offset),
+		  [rseq_offset]		"r" (rseq_offset),
 		  /* cmp2 input */
 		  [v2]			"m" (*v2),
 		  [expect2]		"r" (expect2),
@@ -581,7 +581,7 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 #endif
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_offset]		"r" ((long)rseq_offset),
+		  [rseq_offset]		"r" (rseq_offset),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),

tools/testing/selftests/rseq/rseq.c

@@ -27,16 +27,17 @@
 #include <signal.h>
 #include <limits.h>
 #include <dlfcn.h>
+#include <stddef.h>
 
 #include "../kselftest.h"
 #include "rseq.h"
 
-static const int *libc_rseq_offset_p;
+static const ptrdiff_t *libc_rseq_offset_p;
 static const unsigned int *libc_rseq_size_p;
 static const unsigned int *libc_rseq_flags_p;
 
 /* Offset from the thread pointer to the rseq area.  */
-int rseq_offset;
+ptrdiff_t rseq_offset;
 
 /* Size of the registered rseq area.  0 if the registration was
    unsuccessful.  */

tools/testing/selftests/rseq/rseq.h

@@ -16,6 +16,7 @@
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <stddef.h>
 #include "rseq-abi.h"
 #include "compiler.h"
 
@@ -47,7 +48,7 @@
 #include "rseq-thread-pointer.h"
 
 /* Offset from the thread pointer to the rseq area.  */
-extern int rseq_offset;
+extern ptrdiff_t rseq_offset;
 /* Size of the registered rseq area.  0 if the registration was
    unsuccessful.  */
 extern unsigned int rseq_size;