arm64: fix implementation of mmap2 compat syscall

The arm mmap2 syscall takes the offset in units of 4K, thus with 64K pages
the offset needs to be scaled to units of pages.

Signed-off-by: Andreas Schwab <schwab@suse.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
[will: removed redundant lr parameter, localised PAGE_SHIFT #if check]
Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h
index 27224426e0bf920de713c22cd4b6ca125c84d9bf..cef934a90f17ecec303a1dcd12133a962f27b9d1 100644 (file)
--- a/arch/arm64/include/asm/unistd32.h
+++ b/arch/arm64/include/asm/unistd32.h
@@ -406,7 +406,7 @@ __SYSCALL(__NR_vfork, sys_vfork)
 #define __NR_ugetrlimit 191    /* SuS compliant getrlimit */
 __SYSCALL(__NR_ugetrlimit, compat_sys_getrlimit)               /* SuS compliant getrlimit */
 #define __NR_mmap2 192
-__SYSCALL(__NR_mmap2, sys_mmap_pgoff)
+__SYSCALL(__NR_mmap2, compat_sys_mmap2_wrapper)
 #define __NR_truncate64 193
 __SYSCALL(__NR_truncate64, compat_sys_truncate64_wrapper)
 #define __NR_ftruncate64 194

diff --git a/arch/arm64/kernel/entry32.S b/arch/arm64/kernel/entry32.S
index 9a8f6ae2530e701741f1c8ddb1eff677abbd7ab1..bd9bfaa9269bc59980e89209e22ac0286288f9ef 100644 (file)
--- a/arch/arm64/kernel/entry32.S
+++ b/arch/arm64/kernel/entry32.S
@@ -19,9 +19,12 @@
  */
 
 #include <linux/linkage.h>
+#include <linux/const.h>
 
 #include <asm/assembler.h>
 #include <asm/asm-offsets.h>
+#include <asm/errno.h>
+#include <asm/page.h>
 
 /*
  * System call wrappers for the AArch32 compatibility layer.
@@ -53,6 +56,21 @@ ENTRY(compat_sys_fstatfs64_wrapper)
        b       compat_sys_fstatfs64
 ENDPROC(compat_sys_fstatfs64_wrapper)
 
+/*
+ * Note: off_4k (w5) is always in units of 4K. If we can't do the
+ * requested offset because it is not page-aligned, we return -EINVAL.
+ */
+ENTRY(compat_sys_mmap2_wrapper)
+#if PAGE_SHIFT > 12
+       tst     w5, #~PAGE_MASK >> 12
+       b.ne    1f
+       lsr     w5, w5, #PAGE_SHIFT - 12
+#endif
+       b       sys_mmap_pgoff
+1:     mov     x0, #-EINVAL
+       ret
+ENDPROC(compat_sys_mmap2_wrapper)
+
 /*
  * Wrappers for AArch32 syscalls that either take 64-bit parameters
  * in registers or that take 32-bit parameters which require sign

diff --git a/arch/arm64/kernel/sys32.c b/arch/arm64/kernel/sys32.c
index 2d5ab3c90b820f1b40e0a7a0098cafa4992721ea..a40b1343b819f86bdf4a0e80f143a12425f8fd6b 100644 (file)
--- a/arch/arm64/kernel/sys32.c
+++ b/arch/arm64/kernel/sys32.c
@@ -37,6 +37,7 @@ asmlinkage long compat_sys_readahead_wrapper(void);
 asmlinkage long compat_sys_fadvise64_64_wrapper(void);
 asmlinkage long compat_sys_sync_file_range2_wrapper(void);
 asmlinkage long compat_sys_fallocate_wrapper(void);
+asmlinkage long compat_sys_mmap2_wrapper(void);
 
 #undef __SYSCALL
 #define __SYSCALL(nr, sym)     [nr] = sym,