On Fri, May 06, 2016 at 08:16:48PM +0800, Zhangjian (Bamvor) wrote: > Hi, > > On 2016/4/6 6:08, Yury Norov wrote: > >From: Andrew Pinski <apinski@xxxxxxxxxx> > > > >Add a separate syscall-table for ILP32, which dispatches either to native > >LP64 system call implementation or to compat-syscalls, as appropriate. > > > >Signed-off-by: Andrew Pinski <Andrew.Pinski@xxxxxxxxxxxxxxxxxx> > >Signed-off-by: Yury Norov <ynorov@xxxxxxxxxxxxxxxxxx> > >--- > > arch/arm64/include/asm/unistd.h | 11 ++++++- > > arch/arm64/kernel/Makefile | 2 +- > > arch/arm64/kernel/entry.S | 12 +++++++- > > arch/arm64/kernel/sys_ilp32.c | 65 +++++++++++++++++++++++++++++++++++++++++ > > 4 files changed, 87 insertions(+), 3 deletions(-) > > create mode 100644 arch/arm64/kernel/sys_ilp32.c > > > >diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h > >index 2971dea..5ea18ef 100644 > >--- a/arch/arm64/include/asm/unistd.h > >+++ b/arch/arm64/include/asm/unistd.h > >@@ -13,9 +13,18 @@ > > * You should have received a copy of the GNU General Public License > > * along with this program. If not, see <http://www.gnu.org/licenses/>. > > */ > >+ > >+#ifdef CONFIG_COMPAT > >+#define __ARCH_WANT_COMPAT_STAT64 > >+#endif > >+ > >+#ifdef CONFIG_ARM64_ILP32 > >+#define __ARCH_WANT_COMPAT_SYS_PREADV64 > >+#define __ARCH_WANT_COMPAT_SYS_PWRITEV64 > >+#endif > >+ > > #ifdef CONFIG_AARCH32_EL0 > > #define __ARCH_WANT_COMPAT_SYS_GETDENTS64 > >-#define __ARCH_WANT_COMPAT_STAT64 > > #define __ARCH_WANT_SYS_GETHOSTNAME > > #define __ARCH_WANT_SYS_PAUSE > > #define __ARCH_WANT_SYS_GETPGRP > >diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile > >index 9dfdf86..7aa65ea 100644 > >--- a/arch/arm64/kernel/Makefile > >+++ b/arch/arm64/kernel/Makefile > >@@ -28,7 +28,7 @@ $(obj)/%.stub.o: $(obj)/%.o FORCE > > arm64-obj-$(CONFIG_AARCH32_EL0) += sys32.o kuser32.o signal32.o \ > > sys_compat.o entry32.o \ > > ../../arm/kernel/opcodes.o binfmt_elf32.o > >-arm64-obj-$(CONFIG_ARM64_ILP32) += binfmt_ilp32.o > >+arm64-obj-$(CONFIG_ARM64_ILP32) += binfmt_ilp32.o sys_ilp32.o > > arm64-obj-$(CONFIG_FUNCTION_TRACER) += ftrace.o entry-ftrace.o > > arm64-obj-$(CONFIG_MODULES) += arm64ksyms.o module.o > > arm64-obj-$(CONFIG_ARM64_MODULE_PLTS) += module-plts.o > >diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S > >index cf4d1ae..1f7a145 100644 > >--- a/arch/arm64/kernel/entry.S > >+++ b/arch/arm64/kernel/entry.S > >@@ -715,9 +715,13 @@ ENDPROC(ret_from_fork) > > */ > > .align 6 > > el0_svc: > >- adrp stbl, sys_call_table // load syscall table pointer > > uxtw scno, w8 // syscall number in w8 > > mov sc_nr, #__NR_syscalls > >+#ifdef CONFIG_ARM64_ILP32 > >+ ldr x16, [tsk, #TI_FLAGS] > >+ tbnz x16, #TIF_32BIT_AARCH64, el0_ilp32_svc // We are using ILP32 > >+#endif > >+ adrp stbl, sys_call_table // load syscall table pointer > > el0_svc_naked: // compat entry point > > stp x0, scno, [sp, #S_ORIG_X0] // save the original x0 and syscall number > > enable_dbg_and_irq > >@@ -737,6 +741,12 @@ ni_sys: > > b ret_fast_syscall > > ENDPROC(el0_svc) > > > >+#ifdef CONFIG_ARM64_ILP32 > >+el0_ilp32_svc: > >+ adrp stbl, sys_call_ilp32_table // load syscall table pointer > >+ b el0_svc_naked > >+#endif > >+ > > /* > > * This is the really slow path. We're going to be doing context > > * switches, and waiting for our parent to respond. > >diff --git a/arch/arm64/kernel/sys_ilp32.c b/arch/arm64/kernel/sys_ilp32.c > >new file mode 100644 > >index 0000000..0996d8e > >--- /dev/null > >+++ b/arch/arm64/kernel/sys_ilp32.c > >@@ -0,0 +1,65 @@ > >+/* > >+ * AArch64- ILP32 specific system calls implementation > >+ * > >+ * Copyright (C) 2016 Cavium Inc. > >+ * Author: Andrew Pinski <apinski@xxxxxxxxxx> > >+ * > >+ * This program is free software; you can redistribute it and/or modify > >+ * it under the terms of the GNU General Public License version 2 as > >+ * published by the Free Software Foundation. > >+ * > >+ * This program is distributed in the hope that it will be useful, > >+ * but WITHOUT ANY WARRANTY; without even the implied warranty of > >+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > >+ * GNU General Public License for more details. > >+ * > >+ * You should have received a copy of the GNU General Public License > >+ * along with this program. If not, see <http://www.gnu.org/licenses/>. > >+ */ > >+ > >+#include <linux/compiler.h> > >+#include <linux/errno.h> > >+#include <linux/fs.h> > >+#include <linux/mm.h> > >+#include <linux/msg.h> > >+#include <linux/export.h> > >+#include <linux/sched.h> > >+#include <linux/slab.h> > >+#include <linux/syscalls.h> > >+#include <linux/compat.h> > >+#include <asm-generic/syscalls.h> > >+ > >+/* Using non-compat syscalls where necessary */ > >+#define compat_sys_fadvise64_64 sys_fadvise64_64 > >+#define compat_sys_fallocate sys_fallocate > >+#define compat_sys_ftruncate64 sys_ftruncate > >+#define compat_sys_lookup_dcookie sys_lookup_dcookie > >+#define compat_sys_pread64 sys_pread64 > >+#define compat_sys_pwrite64 sys_pwrite64 > >+#define compat_sys_readahead sys_readahead > >+#define compat_sys_shmat sys_shmat > >+#define compat_sys_sync_file_range sys_sync_file_range > >+#define compat_sys_truncate64 sys_truncate > >+#define sys_llseek sys_lseek > >+#define sys_mmap2 sys_mmap > I am a little bit confused here. We wrap the mmap to mmap2 in glibc > without shift the 4096 and We map mmap2 to mmap in kernel which > means we shift with the real page size. It works unless the > application want to mmap the offset bigger then 2G. In ILP32 app, > if the offset is bigger than 2G(e.g. 0xfb000000), it is a negative > number and extend to 64bit nagetive number in kernel > (0xfffffff fb000000). I add the "COMPAT_SYSCALL_WRAP6(mmap, ...)" in > kernel/compat_wrapper.c. But it is not works. I am not sure if it is > already sign extended in userspace. > > On the other hand, I read the code of mmap in arm and other > architecture. Usually, they will shift 4096 in userspace and shift > others in kernel if needed. Should we follow the similar ways or we > could call mmap_pgoff in glibc and do the shift according the real > page shift(getpages())? > > Thanks > > Bamvor > > Hi, AFAIR, here we don't shift offset, as it's 64-bit both in user- and kernel-space, and just pass it from user to kernel thru glibc with no changes. It definitely works, as there are many mappings made by linker and libc in 2G+ area, and there are no problems with them. This is a typical ILP32 application map: 00400000-00401000 r-xp 00000000 08:00 130400 /root/mykill 00410000-00411000 rwxp 00000000 08:00 130400 /root/mykill 00527000-00549000 rwxp 00000000 00:00 0 [heap] c6278000-c6298000 rwxp 00000000 00:00 0 c6298000-c63d0000 r-xp 00000000 08:00 135293 /root/sys-root/libilp32/libc-2.22.so c63d0000-c63e0000 ---p 00138000 08:00 135293 /root/sys-root/libilp32/libc-2.22.so c63e0000-c63e2000 r-xp 00138000 08:00 135293 /root/sys-root/libilp32/libc-2.22.so c63e2000-c63e3000 rwxp 0013a000 08:00 135293 /root/sys-root/libilp32/libc-2.22.so c63e3000-c63e6000 rwxp 00000000 00:00 0 c63e6000-c63fc000 r-xp 00000000 08:00 135313 /root/sys-root/libilp32/libpthread-2.22.so c63fc000-c640b000 ---p 00016000 08:00 135313 /root/sys-root/libilp32/libpthread-2.22.so c640b000-c640c000 r-xp 00015000 08:00 135313 /root/sys-root/libilp32/libpthread-2.22.so c640c000-c640d000 rwxp 00016000 08:00 135313 /root/sys-root/libilp32/libpthread-2.22.so c640d000-c640f000 rwxp 00000000 00:00 0 c640f000-c642c000 r-xp 00000000 08:00 135288 /root/sys-root/libilp32/ld-2.22.so c6437000-c6439000 rwxp 00000000 00:00 0 c6439000-c643a000 r--p 00000000 00:00 0 [vvar] c643a000-c643b000 r-xp 00000000 00:00 0 [vdso] c643b000-c643c000 r-xp 0001c000 08:00 135288 /root/sys-root/libilp32/ld-2.22.so c643c000-c643d000 rwxp 0001d000 08:00 135288 /root/sys-root/libilp32/ld-2.22.so ffe2d000-ffe4e000 rw-p 00000000 00:00 0 [stack] > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
