parisc: Align parisc MADV_XXX constants with all other architectures

commit 71bdea6f798b425bc0003780b13e3fdecb16a010 upstream.

Adjust some MADV_XXX constants to be in sync what their values are on
all other platforms. There is currently no reason to have an own
numbering on parisc, but it requires workarounds in many userspace
sources (e.g. glibc, qemu, ...) - which are often forgotten and thus
introduce bugs and different behaviour on parisc.

A wrapper avoids an ABI breakage for existing userspace applications by
translating any old values to the new ones, so this change allows us to
move over all programs to the new ABI over time.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 36 insertions, 10 deletions

diff --git a/arch/parisc/include/uapi/asm/mman.h b/arch/parisc/include/uapi/asm/mman.h
index d1af0d74a188..62f2a34f9438 100644
--- a/arch/parisc/include/uapi/asm/mman.h
+++ b/arch/parisc/include/uapi/asm/mman.h
@@ -48,25 +48,24 @@
 #define MADV_DONTFORK	10		/* don't inherit across fork */
 #define MADV_DOFORK	11		/* do inherit across fork */
 
-#define MADV_MERGEABLE   65		/* KSM may merge identical pages */
-#define MADV_UNMERGEABLE 66		/* KSM may not merge identical pages */
+#define MADV_MERGEABLE   12		/* KSM may merge identical pages */
+#define MADV_UNMERGEABLE 13		/* KSM may not merge identical pages */
 
-#define MADV_HUGEPAGE	67		/* Worth backing with hugepages */
-#define MADV_NOHUGEPAGE	68		/* Not worth backing with hugepages */
+#define MADV_HUGEPAGE	14		/* Worth backing with hugepages */
+#define MADV_NOHUGEPAGE 15		/* Not worth backing with hugepages */
 
-#define MADV_DONTDUMP   69		/* Explicity exclude from the core dump,
+#define MADV_DONTDUMP   16		/* Explicity exclude from the core dump,
 					   overrides the coredump filter bits */
-#define MADV_DODUMP	70		/* Clear the MADV_NODUMP flag */
+#define MADV_DODUMP	17		/* Clear the MADV_NODUMP flag */
 
-#define MADV_WIPEONFORK 71		/* Zero memory on fork, child only */
-#define MADV_KEEPONFORK 72		/* Undo MADV_WIPEONFORK */
+#define MADV_WIPEONFORK 18		/* Zero memory on fork, child only */
+#define MADV_KEEPONFORK 19		/* Undo MADV_WIPEONFORK */
 
 #define MADV_HWPOISON     100		/* poison a page for testing */
 #define MADV_SOFT_OFFLINE 101		/* soft offline page for testing */
 
 /* compatibility flags */
 #define MAP_FILE	0
-#define MAP_VARIABLE	0
 
 #define PKEY_DISABLE_ACCESS	0x1
 #define PKEY_DISABLE_WRITE	0x2
diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c
index 378a754ca186..3b7ffa91c6a0 100644
--- a/arch/parisc/kernel/sys_parisc.c
+++ b/arch/parisc/kernel/sys_parisc.c
@@ -385,3 +385,30 @@ long parisc_personality(unsigned long personality)
 
 	return err;
 }
+
+/*
+ * madvise() wrapper
+ *
+ * Up to kernel v6.1 parisc has different values than all other
+ * platforms for the MADV_xxx flags listed below.
+ * To keep binary compatibility with existing userspace programs
+ * translate the former values to the new values.
+ *
+ * XXX: Remove this wrapper in year 2025 (or later)
+ */
+
+asmlinkage notrace long parisc_madvise(unsigned long start, size_t len_in, int behavior)
+{
+	switch (behavior) {
+	case 65: behavior = MADV_MERGEABLE;	break;
+	case 66: behavior = MADV_UNMERGEABLE;	break;
+	case 67: behavior = MADV_HUGEPAGE;	break;
+	case 68: behavior = MADV_NOHUGEPAGE;	break;
+	case 69: behavior = MADV_DONTDUMP;	break;
+	case 70: behavior = MADV_DODUMP;	break;
+	case 71: behavior = MADV_WIPEONFORK;	break;
+	case 72: behavior = MADV_KEEPONFORK;	break;
+	}
+
+	return sys_madvise(start, len_in, behavior);
+}
diff --git a/arch/parisc/kernel/syscall_table.S b/arch/parisc/kernel/syscall_table.S
index 6308749359e4..41d68e70c87f 100644
--- a/arch/parisc/kernel/syscall_table.S
+++ b/arch/parisc/kernel/syscall_table.S
@@ -195,7 +195,7 @@
 	ENTRY_COMP(sysinfo)
 	ENTRY_SAME(shutdown)
 	ENTRY_SAME(fsync)
-	ENTRY_SAME(madvise)
+	ENTRY_OURS(madvise)
 	ENTRY_SAME(clone_wrapper)	/* 120 */
 	ENTRY_SAME(setdomainname)
 	ENTRY_COMP(sendfile)