Re: [PATCH v4 5/6] add listmount(2) syscall
From: Guenter Roeck <linux@roeck-us.net>
Date: 2024-01-12 05:24:28
Also in:
linux-api, linux-fsdevel, linux-man, lkml
Subsystem:
superh, the rest · Maintainers:
Yoshinori Sato, Rich Felker, John Paul Adrian Glaubitz, Linus Torvalds
On Thu, Jan 11, 2024 at 07:40:32PM -0800, Linus Torvalds wrote:
On Thu, 11 Jan 2024 at 15:57, Guenter Roeck [off-list ref] wrote:quoted
I wonder if something may be wrong with the definition and use of __m for u64 accesses. The code below also fixes the build problem.Ok, that looks like the right workaround.
I think I'll go with the code below. It doesn't touch the MMU code
(which for some reason doesn't result in a build failure), and
it generates
! 5071 "fs/namespace.c" 1
mov.l r6,@r1
mov.l r7,@(4,r1)
which seems to be correct. It also matches the pattern used
for __put_user_asm(). Does that make sense ?
Thanks,
Guenter
---diff --git a/arch/sh/include/asm/uaccess_32.h b/arch/sh/include/asm/uaccess_32.h
index 5d7ddc092afd..5ce46b2a95b6 100644
--- a/arch/sh/include/asm/uaccess_32.h
+++ b/arch/sh/include/asm/uaccess_32.h@@ -176,6 +176,7 @@ do { \ } while (0) #endif /* CONFIG_MMU */ +#ifdef CONFIG_MMU #if defined(CONFIG_CPU_LITTLE_ENDIAN) #define __put_user_u64(val,addr,retval) \ ({ \
@@ -221,6 +222,26 @@ __asm__ __volatile__( \ : "r" (val), "m" (__m(addr)), "i" (-EFAULT), "0" (retval) \ : "memory"); }) #endif +#else +#if defined(CONFIG_CPU_LITTLE_ENDIAN) +#define __put_user_u64(val,addr,retval) \ +({ \ +__asm__ __volatile__( \ + "mov.l %R0,%1\n\t" \ + "mov.l %S0,%T1\n\t" \ + : /* no outputs */ \ + : "r" (val), "m" (*(u64 *)(addr)) \ + : "memory"); }) +#else +({ \ +__asm__ __volatile__( \ + "mov.l %S0,%1\n\t" \ + "mov.l %R0,%T1\n\t" \ + : /* no outputs */ \ + : "r" (val), "m" (*(u64 *)(addr)) \ + : "memory"); }) +#endif +#endif /* CONFIG_MMU */ extern void __put_user_unknown(void);