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Diffstat (limited to 'arch/powerpc/kernel/sys_ppc32.c')
-rw-r--r--arch/powerpc/kernel/sys_ppc32.c38
1 files changed, 29 insertions, 9 deletions
diff --git a/arch/powerpc/kernel/sys_ppc32.c b/arch/powerpc/kernel/sys_ppc32.c
index dcc3c9fd4cfd..1ab4a4d95aba 100644
--- a/arch/powerpc/kernel/sys_ppc32.c
+++ b/arch/powerpc/kernel/sys_ppc32.c
@@ -1,13 +1,23 @@
// SPDX-License-Identifier: GPL-2.0-or-later
/*
- * sys_ppc32.c: Conversion between 32bit and 64bit native syscalls.
+ * sys_ppc32.c: 32-bit system calls with complex calling conventions.
*
* Copyright (C) 2001 IBM
* Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
* Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
*
- * These routines maintain argument size conversion between 32bit and 64bit
- * environment.
+ * 32-bit system calls with 64-bit arguments pass those in register pairs.
+ * This must be specially dealt with on 64-bit kernels. The compat_arg_u64_dual
+ * in generic compat syscalls is not always usable because the register
+ * pairing is constrained depending on preceding arguments.
+ *
+ * An analogous problem exists on 32-bit kernels with ARCH_HAS_SYSCALL_WRAPPER,
+ * the defined system call functions take the pt_regs as an argument, and there
+ * is a mapping macro which maps registers to arguments
+ * (SC_POWERPC_REGS_TO_ARGS) which also does not deal with these 64-bit
+ * arguments.
+ *
+ * This file contains these system calls.
*/
#include <linux/kernel.h>
@@ -47,7 +57,17 @@
#include <asm/syscalls.h>
#include <asm/switch_to.h>
-COMPAT_SYSCALL_DEFINE6(ppc_pread64,
+#ifdef CONFIG_PPC32
+#define PPC32_SYSCALL_DEFINE4 SYSCALL_DEFINE4
+#define PPC32_SYSCALL_DEFINE5 SYSCALL_DEFINE5
+#define PPC32_SYSCALL_DEFINE6 SYSCALL_DEFINE6
+#else
+#define PPC32_SYSCALL_DEFINE4 COMPAT_SYSCALL_DEFINE4
+#define PPC32_SYSCALL_DEFINE5 COMPAT_SYSCALL_DEFINE5
+#define PPC32_SYSCALL_DEFINE6 COMPAT_SYSCALL_DEFINE6
+#endif
+
+PPC32_SYSCALL_DEFINE6(ppc_pread64,
unsigned int, fd,
char __user *, ubuf, compat_size_t, count,
u32, reg6, u32, pos1, u32, pos2)
@@ -55,7 +75,7 @@ COMPAT_SYSCALL_DEFINE6(ppc_pread64,
return ksys_pread64(fd, ubuf, count, merge_64(pos1, pos2));
}
-COMPAT_SYSCALL_DEFINE6(ppc_pwrite64,
+PPC32_SYSCALL_DEFINE6(ppc_pwrite64,
unsigned int, fd,
const char __user *, ubuf, compat_size_t, count,
u32, reg6, u32, pos1, u32, pos2)
@@ -63,28 +83,28 @@ COMPAT_SYSCALL_DEFINE6(ppc_pwrite64,
return ksys_pwrite64(fd, ubuf, count, merge_64(pos1, pos2));
}
-COMPAT_SYSCALL_DEFINE5(ppc_readahead,
+PPC32_SYSCALL_DEFINE5(ppc_readahead,
int, fd, u32, r4,
u32, offset1, u32, offset2, u32, count)
{
return ksys_readahead(fd, merge_64(offset1, offset2), count);
}
-COMPAT_SYSCALL_DEFINE4(ppc_truncate64,
+PPC32_SYSCALL_DEFINE4(ppc_truncate64,
const char __user *, path, u32, reg4,
unsigned long, len1, unsigned long, len2)
{
return ksys_truncate(path, merge_64(len1, len2));
}
-COMPAT_SYSCALL_DEFINE4(ppc_ftruncate64,
+PPC32_SYSCALL_DEFINE4(ppc_ftruncate64,
unsigned int, fd, u32, reg4,
unsigned long, len1, unsigned long, len2)
{
return ksys_ftruncate(fd, merge_64(len1, len2));
}
-COMPAT_SYSCALL_DEFINE6(ppc32_fadvise64,
+PPC32_SYSCALL_DEFINE6(ppc32_fadvise64,
int, fd, u32, unused, u32, offset1, u32, offset2,
size_t, len, int, advice)
{