Subject: [PATCH 13/15] syscalls: mmap(): use unsigned offset type consistently

From: Arnd Bergmann <[email-masked]>
Date: Thu, 20 Jun 2024 18:23:14 +0200

From: Arnd Bergmann <[email-masked]>

Most architectures that implement the old-style mmap() with byte offset
use 'unsigned long' as the type for that offset, but microblaze and
riscv have the off_t type that is shared with userspace, matching the
prototype in include/asm-generic/syscalls.h.

Make this consistent by using an unsigned argument everywhere. This
changes the behavior slightly, as the argument is shifted to a page
number, and an user input with the top bit set would result in a
negative page offset rather than a large one as we use elsewhere.

For riscv, the 32-bit sys_mmap2() definition actually used a custom
type that is different from the global declaration, but this was
missed due to an incorrect type check.

Signed-off-by: Arnd Bergmann <[email-masked]>
---
 arch/csky/kernel/syscall.c              | 2 +-
 arch/loongarch/kernel/syscall.c         | 2 +-
 arch/microblaze/kernel/sys_microblaze.c | 2 +-
 arch/riscv/kernel/sys_riscv.c           | 4 ++--
 include/asm-generic/syscalls.h          | 2 +-
 5 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/csky/kernel/syscall.c b/arch/csky/kernel/syscall.c
index 3d30e58a45d2..4540a271ee39 100644
--- a/arch/csky/kernel/syscall.c
+++ b/arch/csky/kernel/syscall.c
@@ -20,7 +20,7 @@ SYSCALL_DEFINE6(mmap2,
 	unsigned long, prot,
 	unsigned long, flags,
 	unsigned long, fd,
-	off_t, offset)
+	unsigned long, offset)
 {
 	if (unlikely(offset & (~PAGE_MASK >> 12)))
 		return -EINVAL;
diff --git a/arch/loongarch/kernel/syscall.c b/arch/loongarch/kernel/syscall.c
index b4c5acd7aa3b..8801611143ab 100644
--- a/arch/loongarch/kernel/syscall.c
+++ b/arch/loongarch/kernel/syscall.c
@@ -22,7 +22,7 @@
 #define __SYSCALL(nr, call)	[nr] = (call),
 
 SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len, unsigned long,
-		prot, unsigned long, flags, unsigned long, fd, off_t, offset)
+		prot, unsigned long, flags, unsigned long, fd, unsigned long, offset)
 {
 	if (offset & ~PAGE_MASK)
 		return -EINVAL;
diff --git a/arch/microblaze/kernel/sys_microblaze.c b/arch/microblaze/kernel/sys_microblaze.c
index ed9f34da1a2a..0850b099f300 100644
--- a/arch/microblaze/kernel/sys_microblaze.c
+++ b/arch/microblaze/kernel/sys_microblaze.c
@@ -35,7 +35,7 @@
 
 SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
 		unsigned long, prot, unsigned long, flags, unsigned long, fd,
-		off_t, pgoff)
+		unsigned long, pgoff)
 {
 	if (pgoff & ~PAGE_MASK)
 		return -EINVAL;
diff --git a/arch/riscv/kernel/sys_riscv.c b/arch/riscv/kernel/sys_riscv.c
index 64155323cc92..d77afe05578f 100644
--- a/arch/riscv/kernel/sys_riscv.c
+++ b/arch/riscv/kernel/sys_riscv.c
@@ -23,7 +23,7 @@ static long riscv_sys_mmap(unsigned long addr, unsigned long len,
 #ifdef CONFIG_64BIT
 SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
 	unsigned long, prot, unsigned long, flags,
-	unsigned long, fd, off_t, offset)
+	unsigned long, fd, unsigned long, offset)
 {
 	return riscv_sys_mmap(addr, len, prot, flags, fd, offset, 0);
 }
@@ -32,7 +32,7 @@ SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
 #if defined(CONFIG_32BIT) || defined(CONFIG_COMPAT)
 SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
 	unsigned long, prot, unsigned long, flags,
-	unsigned long, fd, off_t, offset)
+	unsigned long, fd, unsigned long, offset)
 {
 	/*
 	 * Note that the shift for mmap2 is constant (12),
diff --git a/include/asm-generic/syscalls.h b/include/asm-generic/syscalls.h
index 933ca6581aba..fabcefe8a80a 100644
--- a/include/asm-generic/syscalls.h
+++ b/include/asm-generic/syscalls.h
@@ -19,7 +19,7 @@ asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
 #ifndef sys_mmap
 asmlinkage long sys_mmap(unsigned long addr, unsigned long len,
 			unsigned long prot, unsigned long flags,
-			unsigned long fd, off_t pgoff);
+			unsigned long fd, unsigned long off);
 #endif
 
 #ifndef sys_rt_sigreturn
-- 
2.39.2