[PATCH v6 13/20] arm64: ilp32: share aarch32 syscall wrappers to ilp32
From: catalin.marinas@arm.com (Catalin Marinas)
Date: 2015-12-22 12:25:22
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On Wed, Dec 16, 2015 at 12:42:39AM +0300, Yury Norov wrote:
statfs64, fstat64 and mmap_pgoff has wrappers that needed both by aarch32 and ilp32 to workaround some issues. Here we create common file to share aarch32 workarounds to with ilp32 code.
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quoted hunk ↗ jump to hunk
--- /dev/null +++ b/arch/arm64/kernel/entry32-common.S@@ -0,0 +1,37 @@ +#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> + +ENTRY(compat_sys_statfs64_wrapper) + mov w3, #84 + cmp w1, #88 + csel w1, w3, w1, eq + b compat_sys_statfs64 +ENDPROC(compat_sys_statfs64_wrapper) + +ENTRY(compat_sys_fstatfs64_wrapper) + mov w3, #84 + cmp w1, #88 + csel w1, w3, w1, eq + b compat_sys_fstatfs64 +ENDPROC(compat_sys_fstatfs64_wrapper)
I'm not convinced we need these wrappers for ILP32. They've been introduced on arch/arm many years ago by commit Fixes: 713c481519f1 ([ARM] 3108/2: old ABI compat: statfs64 and fstatfs64) to deal with user space passing a size of 88 (the EABI size of struct compat_statfs64 without the packing and alignment attribute). Since that commit, the sizeof(struct compat_statfs64) is 84 already. This should be the case with the new ILP32 exported headers (no backwards compatibility), so user space should never pass 88 as size. Therefore we could call compat_sys_(f)statfs64 directly without wrappers. -- Catalin