| Message ID | 20200615130032.931285-3-hch@lst.de (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [1/6] exec: cleanup the execve wrappers | expand |
On Mon, Jun 15, 2020 at 3:00 PM Christoph Hellwig <hch@lst.de> wrote: > > The only differenence betweeen the compat exec* syscalls and their > native versions is that compat_ptr sign extension, and the fact that > the pointer arithmetics for the two dimensional arrays needs to use > the compat pointer size. Instead of the compat wrappers and the > struct user_arg_ptr machinery just use in_compat_syscall() to do the > right thing for the compat case deep inside get_user_arg_ptr(). > > Signed-off-by: Christoph Hellwig <hch@lst.de> Nice! I have an older patch doing the same for sys_mount() somewhere, but never got around to send that. One day we should see if we can just do this for all of them. > - > -static const char __user *get_user_arg_ptr(struct user_arg_ptr argv, int nr) > +static const char __user * > +get_user_arg_ptr(const char __user *const __user *argv, int nr) > { > const char __user *native; > > #ifdef CONFIG_COMPAT > - if (unlikely(argv.is_compat)) { > + if (in_compat_syscall()) { > + const compat_uptr_t __user *compat_argv = > + compat_ptr((unsigned long)argv); > compat_uptr_t compat; > > - if (get_user(compat, argv.ptr.compat + nr)) > + if (get_user(compat, compat_argv + nr)) > return ERR_PTR(-EFAULT); > > return compat_ptr(compat); > } > #endif I would expect that the "#ifdef CONFIG_COMPAT" can be removed now, since compat_ptr() and in_compat_syscall() are now defined unconditionally. I have not tried that though. > +/* > + * x32 syscalls are listed in the same table as x86_64 ones, so we need to > + * define compat syscalls that are exactly the same as the native version for > + * the syscall table machinery to work. Sigh.. > + */ > +#ifdef CONFIG_X86_X32 > COMPAT_SYSCALL_DEFINE3(execve, const char __user *, filename, > - const compat_uptr_t __user *, argv, > - const compat_uptr_t __user *, envp) > + const char __user *const __user *, argv, > + const char __user *const __user *, envp) > { > - return do_compat_execve(AT_FDCWD, getname(filename), argv, envp, 0); > + return do_execveat(AT_FDCWD, getname(filename), argv, envp, 0, NULL); > } Maybe move it to arch/x86/kernel/process_64.c or arch/x86/entry/syscall_x32.c to keep it out of the common code if this is needed. I don't really understand the comment, why can't this just use this? --- a/arch/x86/entry/syscalls/syscall_64.tbl +++ b/arch/x86/entry/syscalls/syscall_64.tbl @@ -379,7 +379,7 @@ 517 x32 recvfrom compat_sys_recvfrom 518 x32 sendmsg compat_sys_sendmsg 519 x32 recvmsg compat_sys_recvmsg -520 x32 execve compat_sys_execve +520 x32 execve sys_execve 521 x32 ptrace compat_sys_ptrace 522 x32 rt_sigpending compat_sys_rt_sigpending 523 x32 rt_sigtimedwait compat_sys_rt_sigtimedwait_time64 @@ -404,7 +404,7 @@ 542 x32 getsockopt compat_sys_getsockopt 543 x32 io_setup compat_sys_io_setup 544 x32 io_submit compat_sys_io_submit -545 x32 execveat compat_sys_execveat +545 x32 execveat sys_execveat 546 x32 preadv2 compat_sys_preadv64v2 547 x32 pwritev2 compat_sys_pwritev64v2 548 x32 process_madvise compat_sys_process_madvise Arnd
On Mon, Jun 15, 2020 at 03:31:35PM +0200, Arnd Bergmann wrote: > > #ifdef CONFIG_COMPAT > > - if (unlikely(argv.is_compat)) { > > + if (in_compat_syscall()) { > > + const compat_uptr_t __user *compat_argv = > > + compat_ptr((unsigned long)argv); > > compat_uptr_t compat; > > > > - if (get_user(compat, argv.ptr.compat + nr)) > > + if (get_user(compat, compat_argv + nr)) > > return ERR_PTR(-EFAULT); > > > > return compat_ptr(compat); > > } > > #endif > > I would expect that the "#ifdef CONFIG_COMPAT" can be removed > now, since compat_ptr() and in_compat_syscall() are now defined > unconditionally. I have not tried that though. True, I'll give it a spin. > > +/* > > + * x32 syscalls are listed in the same table as x86_64 ones, so we need to > > + * define compat syscalls that are exactly the same as the native version for > > + * the syscall table machinery to work. Sigh.. > > + */ > > +#ifdef CONFIG_X86_X32 > > COMPAT_SYSCALL_DEFINE3(execve, const char __user *, filename, > > - const compat_uptr_t __user *, argv, > > - const compat_uptr_t __user *, envp) > > + const char __user *const __user *, argv, > > + const char __user *const __user *, envp) > > { > > - return do_compat_execve(AT_FDCWD, getname(filename), argv, envp, 0); > > + return do_execveat(AT_FDCWD, getname(filename), argv, envp, 0, NULL); > > } > > Maybe move it to arch/x86/kernel/process_64.c or arch/x86/entry/syscall_x32.c > to keep it out of the common code if this is needed. I'd rather keep it in common code as that allows all the low-level exec stuff to be marked static, and avoid us growing new pointless compat variants through copy and paste. smart compiler to d > I don't really understand > the comment, why can't this just use this? That errors out with: ld: arch/x86/entry/syscall_x32.o:(.rodata+0x1040): undefined reference to `__x32_sys_execve' ld: arch/x86/entry/syscall_x32.o:(.rodata+0x1108): undefined reference to `__x32_sys_execveat' make: *** [Makefile:1139: vmlinux] Error 1
On Mon, Jun 15, 2020 at 4:12 PM Christoph Hellwig <hch@lst.de> wrote: > On Mon, Jun 15, 2020 at 03:31:35PM +0200, Arnd Bergmann wrote: > > > I don't really understand > > the comment, why can't this just use this? > > That errors out with: > > ld: arch/x86/entry/syscall_x32.o:(.rodata+0x1040): undefined reference to > `__x32_sys_execve' > ld: arch/x86/entry/syscall_x32.o:(.rodata+0x1108): undefined reference to > `__x32_sys_execveat' > make: *** [Makefile:1139: vmlinux] Error 1 Ah, I see: it's marked x32-only, so arch/x86/entry/syscall_x32.c uses the __x32 prefix instead of the __x64 one. Marking it 'common' instead would make it work, but also create an extra entry point for native processes, something that commit 6365b842aae4 ("x86/syscalls: Split the x32 syscalls into their own table") was trying to avoid. Arnd
On Mon, Jun 15, 2020 at 04:40:28PM +0200, Arnd Bergmann wrote: > > ld: arch/x86/entry/syscall_x32.o:(.rodata+0x1040): undefined reference to > > `__x32_sys_execve' > > ld: arch/x86/entry/syscall_x32.o:(.rodata+0x1108): undefined reference to > > `__x32_sys_execveat' > > make: *** [Makefile:1139: vmlinux] Error 1 > > Ah, I see: it's marked x32-only, so arch/x86/entry/syscall_x32.c > uses the __x32 prefix instead of the __x64 one. Marking it 'common' > instead would make it work, but also create an extra entry point > for native processes, something that commit > 6365b842aae4 ("x86/syscalls: Split the x32 syscalls into their own table") > was trying to avoid. Marking it common also doesn't compile at all because __NR_execve and __NR_execveat get redefined in unistd_64.h. I then tried to rename the x32 versions, which failed in yet another way. At that point I gave up instead of digging myself into a deeper hole..
On Mon, Jun 15, 2020 at 4:43 PM Christoph Hellwig <hch@lst.de> wrote: > > On Mon, Jun 15, 2020 at 04:40:28PM +0200, Arnd Bergmann wrote: > > > ld: arch/x86/entry/syscall_x32.o:(.rodata+0x1040): undefined reference to > > > `__x32_sys_execve' > > > ld: arch/x86/entry/syscall_x32.o:(.rodata+0x1108): undefined reference to > > > `__x32_sys_execveat' > > > make: *** [Makefile:1139: vmlinux] Error 1 > > > > Ah, I see: it's marked x32-only, so arch/x86/entry/syscall_x32.c > > uses the __x32 prefix instead of the __x64 one. Marking it 'common' > > instead would make it work, but also create an extra entry point > > for native processes, something that commit > > 6365b842aae4 ("x86/syscalls: Split the x32 syscalls into their own table") > > was trying to avoid. > > Marking it common also doesn't compile at all because __NR_execve > and __NR_execveat get redefined in unistd_64.h. I then tried to rename > the x32 versions, which failed in yet another way. At that point I gave > up instead of digging myself into a deeper hole.. How about this one: diff --git a/arch/x86/entry/syscall_x32.c b/arch/x86/entry/syscall_x32.c index 3d8d70d3896c..0ce15807cf54 100644 --- a/arch/x86/entry/syscall_x32.c +++ b/arch/x86/entry/syscall_x32.c @@ -16,6 +16,9 @@ #undef __SYSCALL_X32 #undef __SYSCALL_COMMON +#define __x32_sys_execve __x64_sys_execve +#define __x32_sys_execveat __x64_sys_execveat + #define __SYSCALL_X32(nr, sym) [nr] = __x32_##sym, #define __SYSCALL_COMMON(nr, sym) [nr] = __x64_##sym, Still ugly, but much simpler and more localized (if it works). Arnd
On Mon, Jun 15, 2020 at 10:13 AM Christoph Hellwig <hch@lst.de> wrote: > > On Mon, Jun 15, 2020 at 03:31:35PM +0200, Arnd Bergmann wrote: > > > #ifdef CONFIG_COMPAT > > > - if (unlikely(argv.is_compat)) { > > > + if (in_compat_syscall()) { > > > + const compat_uptr_t __user *compat_argv = > > > + compat_ptr((unsigned long)argv); > > > compat_uptr_t compat; > > > > > > - if (get_user(compat, argv.ptr.compat + nr)) > > > + if (get_user(compat, compat_argv + nr)) > > > return ERR_PTR(-EFAULT); > > > > > > return compat_ptr(compat); > > > } > > > #endif > > > > I would expect that the "#ifdef CONFIG_COMPAT" can be removed > > now, since compat_ptr() and in_compat_syscall() are now defined > > unconditionally. I have not tried that though. > > True, I'll give it a spin. > > > > +/* > > > + * x32 syscalls are listed in the same table as x86_64 ones, so we need to > > > + * define compat syscalls that are exactly the same as the native version for > > > + * the syscall table machinery to work. Sigh.. > > > + */ > > > +#ifdef CONFIG_X86_X32 > > > COMPAT_SYSCALL_DEFINE3(execve, const char __user *, filename, > > > - const compat_uptr_t __user *, argv, > > > - const compat_uptr_t __user *, envp) > > > + const char __user *const __user *, argv, > > > + const char __user *const __user *, envp) > > > { > > > - return do_compat_execve(AT_FDCWD, getname(filename), argv, envp, 0); > > > + return do_execveat(AT_FDCWD, getname(filename), argv, envp, 0, NULL); > > > } > > > > Maybe move it to arch/x86/kernel/process_64.c or arch/x86/entry/syscall_x32.c > > to keep it out of the common code if this is needed. > > I'd rather keep it in common code as that allows all the low-level > exec stuff to be marked static, and avoid us growing new pointless > compat variants through copy and paste. > smart compiler to d > > > I don't really understand > > the comment, why can't this just use this? > > That errors out with: > > ld: arch/x86/entry/syscall_x32.o:(.rodata+0x1040): undefined reference to > `__x32_sys_execve' > ld: arch/x86/entry/syscall_x32.o:(.rodata+0x1108): undefined reference to > `__x32_sys_execveat' > make: *** [Makefile:1139: vmlinux] Error 1 I think I have a fix for this, by modifying the syscall wrappers to add an alias for the __x32 variant to the native __x64_sys_foo(). I'll get back to you with a patch. -- Brian Gerst
On Mon, Jun 15, 2020 at 04:46:15PM +0200, Arnd Bergmann wrote: > How about this one: > > diff --git a/arch/x86/entry/syscall_x32.c b/arch/x86/entry/syscall_x32.c > index 3d8d70d3896c..0ce15807cf54 100644 > --- a/arch/x86/entry/syscall_x32.c > +++ b/arch/x86/entry/syscall_x32.c > @@ -16,6 +16,9 @@ > #undef __SYSCALL_X32 > #undef __SYSCALL_COMMON > > +#define __x32_sys_execve __x64_sys_execve > +#define __x32_sys_execveat __x64_sys_execveat > + arch/x86/entry/syscall_x32.c:19:26: error: ‘__x64_sys_execve’ undeclared here (not in a function); did you mean ‘__x32_sys_execve’? 19 | #define __x32_sys_execve __x64_sys_execve | ^~~~~~~~~~~~~~~~ arch/x86/entry/syscall_x32.c:22:39: note: in expansion of macro ‘__x32_sys_execve’ 22 | #define __SYSCALL_X32(nr, sym) [nr] = __x32_##sym, | ^~~~~~ ./arch/x86/include/generated/asm/syscalls_64.h:344:1: note: in expansion of macro ‘__SYSCALL_X32’ 344 | __SYSCALL_X32(520, sys_execve) | ^~~~~~~~~~~~~ arch/x86/entry/syscall_x32.c:20:28: error: ‘__x64_sys_execveat’ undeclared here (not in a function); did you mean ‘__x32_sys_execveat’? 20 | #define __x32_sys_execveat __x64_sys_execveat | ^~~~~~~~~~~~~~~~~~ arch/x86/entry/syscall_x32.c:22:39: note: in expansion of macro ‘__x32_sys_execveat’ 22 | #define __SYSCALL_X32(nr, sym) [nr] = __x32_##sym, | ^~~~~~ ./arch/x86/include/generated/asm/syscalls_64.h:369:1: note: in expansion of macro ‘__SYSCALL_X32’ 369 | __SYSCALL_X32(545, sys_execveat) | ^~~~~~~~~~~~~ make[2]: *** [scripts/Makefile.build:281: arch/x86/entry/syscall_x32.o] Error 1 make[1]: *** [scripts/Makefile.build:497: arch/x86/entry] Error 2 make[1]: *** Waiting for unfinished jobs.... kernel/exit.o: warning: objtool: __x64_sys_exit_group()+0x14: unreachable instruction make: *** [Makefile:1764: arch/x86] Error 2 make: *** Waiting for unfinished jobs....
On Mon, Jun 15, 2020 at 11:10 AM Christoph Hellwig <hch@lst.de> wrote: > > On Mon, Jun 15, 2020 at 04:46:15PM +0200, Arnd Bergmann wrote: > > How about this one: > > > > diff --git a/arch/x86/entry/syscall_x32.c b/arch/x86/entry/syscall_x32.c > > index 3d8d70d3896c..0ce15807cf54 100644 > > --- a/arch/x86/entry/syscall_x32.c > > +++ b/arch/x86/entry/syscall_x32.c > > @@ -16,6 +16,9 @@ > > #undef __SYSCALL_X32 > > #undef __SYSCALL_COMMON > > > > +#define __x32_sys_execve __x64_sys_execve > > +#define __x32_sys_execveat __x64_sys_execveat > > + > > > arch/x86/entry/syscall_x32.c:19:26: error: ‘__x64_sys_execve’ undeclared here (not in a function); did you mean ‘__x32_sys_execve’? > 19 | #define __x32_sys_execve __x64_sys_execve > | ^~~~~~~~~~~~~~~~ > arch/x86/entry/syscall_x32.c:22:39: note: in expansion of macro ‘__x32_sys_execve’ > 22 | #define __SYSCALL_X32(nr, sym) [nr] = __x32_##sym, > | ^~~~~~ > ./arch/x86/include/generated/asm/syscalls_64.h:344:1: note: in expansion of macro ‘__SYSCALL_X32’ > 344 | __SYSCALL_X32(520, sys_execve) > | ^~~~~~~~~~~~~ > arch/x86/entry/syscall_x32.c:20:28: error: ‘__x64_sys_execveat’ undeclared here (not in a function); did you mean ‘__x32_sys_execveat’? > 20 | #define __x32_sys_execveat __x64_sys_execveat > | ^~~~~~~~~~~~~~~~~~ > arch/x86/entry/syscall_x32.c:22:39: note: in expansion of macro ‘__x32_sys_execveat’ > 22 | #define __SYSCALL_X32(nr, sym) [nr] = __x32_##sym, > | ^~~~~~ > ./arch/x86/include/generated/asm/syscalls_64.h:369:1: note: in expansion of macro ‘__SYSCALL_X32’ > 369 | __SYSCALL_X32(545, sys_execveat) > | ^~~~~~~~~~~~~ > make[2]: *** [scripts/Makefile.build:281: arch/x86/entry/syscall_x32.o] Error 1 > make[1]: *** [scripts/Makefile.build:497: arch/x86/entry] Error 2 > make[1]: *** Waiting for unfinished jobs.... > kernel/exit.o: warning: objtool: __x64_sys_exit_group()+0x14: unreachable instruction > make: *** [Makefile:1764: arch/x86] Error 2 > make: *** Waiting for unfinished jobs.... If you move those aliases above all the __SYSCALL_* defines it will work, since that will get the forward declaration too. This would be the simplest workaround. -- Brian Gerst
On Mon, Jun 15, 2020 at 11:33:49AM -0400, Brian Gerst wrote: > If you move those aliases above all the __SYSCALL_* defines it will > work, since that will get the forward declaration too. This would be > the simplest workaround. That compiles and also passes my exaustive x32 tests (chroot + ls -l). This is the updated version: http://git.infradead.org/users/hch/misc.git/commitdiff/c8d319711ad2f53be003ae8e9be08519068bdcee
On Mon, Jun 15, 2020 at 4:48 PM Brian Gerst <brgerst@gmail.com> wrote: > On Mon, Jun 15, 2020 at 10:13 AM Christoph Hellwig <hch@lst.de> wrote: > > On Mon, Jun 15, 2020 at 03:31:35PM +0200, Arnd Bergmann wrote: > > > > I'd rather keep it in common code as that allows all the low-level > > exec stuff to be marked static, and avoid us growing new pointless > > compat variants through copy and paste. > > smart compiler to d > > > > > I don't really understand > > > the comment, why can't this just use this? > > > > That errors out with: > > > > ld: arch/x86/entry/syscall_x32.o:(.rodata+0x1040): undefined reference to > > `__x32_sys_execve' > > ld: arch/x86/entry/syscall_x32.o:(.rodata+0x1108): undefined reference to > > `__x32_sys_execveat' > > make: *** [Makefile:1139: vmlinux] Error 1 > > I think I have a fix for this, by modifying the syscall wrappers to > add an alias for the __x32 variant to the native __x64_sys_foo(). > I'll get back to you with a patch. Do we actually need the __x32 prefix any more, or could we just change all x32 specific calls to use __x64_compat_sys_foo()? Arnd
On Mon, Jun 15, 2020 at 2:47 PM Arnd Bergmann <arnd@arndb.de> wrote: > > On Mon, Jun 15, 2020 at 4:48 PM Brian Gerst <brgerst@gmail.com> wrote: > > On Mon, Jun 15, 2020 at 10:13 AM Christoph Hellwig <hch@lst.de> wrote: > > > On Mon, Jun 15, 2020 at 03:31:35PM +0200, Arnd Bergmann wrote: > > > > > > > I'd rather keep it in common code as that allows all the low-level > > > exec stuff to be marked static, and avoid us growing new pointless > > > compat variants through copy and paste. > > > smart compiler to d > > > > > > > I don't really understand > > > > the comment, why can't this just use this? > > > > > > That errors out with: > > > > > > ld: arch/x86/entry/syscall_x32.o:(.rodata+0x1040): undefined reference to > > > `__x32_sys_execve' > > > ld: arch/x86/entry/syscall_x32.o:(.rodata+0x1108): undefined reference to > > > `__x32_sys_execveat' > > > make: *** [Makefile:1139: vmlinux] Error 1 > > > > I think I have a fix for this, by modifying the syscall wrappers to > > add an alias for the __x32 variant to the native __x64_sys_foo(). > > I'll get back to you with a patch. > > Do we actually need the __x32 prefix any more, or could we just > change all x32 specific calls to use __x64_compat_sys_foo()? I suppose that would work too. The prefix really describes the register mapping. -- Brian Gerst
diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h index 6d95d0c8bf2f47..141f5d2ff1c34f 100644 --- a/arch/arm64/include/asm/unistd32.h +++ b/arch/arm64/include/asm/unistd32.h @@ -33,7 +33,7 @@ __SYSCALL(__NR_link, sys_link) #define __NR_unlink 10 __SYSCALL(__NR_unlink, sys_unlink) #define __NR_execve 11 -__SYSCALL(__NR_execve, compat_sys_execve) +__SYSCALL(__NR_execve, sys_execve) #define __NR_chdir 12 __SYSCALL(__NR_chdir, sys_chdir) /* 13 was sys_time */ @@ -785,7 +785,7 @@ __SYSCALL(__NR_memfd_create, sys_memfd_create) #define __NR_bpf 386 __SYSCALL(__NR_bpf, sys_bpf) #define __NR_execveat 387 -__SYSCALL(__NR_execveat, compat_sys_execveat) +__SYSCALL(__NR_execveat, sys_execveat) #define __NR_userfaultfd 388 __SYSCALL(__NR_userfaultfd, sys_userfaultfd) #define __NR_membarrier 389 diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl index f777141f52568f..e861b5ab7179c9 100644 --- a/arch/mips/kernel/syscalls/syscall_n32.tbl +++ b/arch/mips/kernel/syscalls/syscall_n32.tbl @@ -64,7 +64,7 @@ 54 n32 getsockopt compat_sys_getsockopt 55 n32 clone __sys_clone 56 n32 fork __sys_fork -57 n32 execve compat_sys_execve +57 n32 execve sys_execve 58 n32 exit sys_exit 59 n32 wait4 compat_sys_wait4 60 n32 kill sys_kill @@ -328,7 +328,7 @@ 317 n32 getrandom sys_getrandom 318 n32 memfd_create sys_memfd_create 319 n32 bpf sys_bpf -320 n32 execveat compat_sys_execveat +320 n32 execveat sys_execveat 321 n32 userfaultfd sys_userfaultfd 322 n32 membarrier sys_membarrier 323 n32 mlock2 sys_mlock2 diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl b/arch/mips/kernel/syscalls/syscall_o32.tbl index 13280625d312e9..bba80f74e9968e 100644 --- a/arch/mips/kernel/syscalls/syscall_o32.tbl +++ b/arch/mips/kernel/syscalls/syscall_o32.tbl @@ -18,7 +18,7 @@ 8 o32 creat sys_creat 9 o32 link sys_link 10 o32 unlink sys_unlink -11 o32 execve sys_execve compat_sys_execve +11 o32 execve sys_execve 12 o32 chdir sys_chdir 13 o32 time sys_time32 14 o32 mknod sys_mknod @@ -367,7 +367,7 @@ 353 o32 getrandom sys_getrandom 354 o32 memfd_create sys_memfd_create 355 o32 bpf sys_bpf -356 o32 execveat sys_execveat compat_sys_execveat +356 o32 execveat sys_execveat 357 o32 userfaultfd sys_userfaultfd 358 o32 membarrier sys_membarrier 359 o32 mlock2 sys_mlock2 diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl index 5a758fa6ec5242..23fa0d0edf3384 100644 --- a/arch/parisc/kernel/syscalls/syscall.tbl +++ b/arch/parisc/kernel/syscalls/syscall.tbl @@ -18,7 +18,7 @@ 8 common creat sys_creat 9 common link sys_link 10 common unlink sys_unlink -11 common execve sys_execve compat_sys_execve +11 common execve sys_execve 12 common chdir sys_chdir 13 32 time sys_time32 13 64 time sys_time @@ -385,7 +385,7 @@ 339 common getrandom sys_getrandom 340 common memfd_create sys_memfd_create 341 common bpf sys_bpf -342 common execveat sys_execveat compat_sys_execveat +342 common execveat sys_execveat 343 common membarrier sys_membarrier 344 common userfaultfd sys_userfaultfd 345 common mlock2 sys_mlock2 diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl index f833a319082247..c52cdab89dc0ae 100644 --- a/arch/powerpc/kernel/syscalls/syscall.tbl +++ b/arch/powerpc/kernel/syscalls/syscall.tbl @@ -20,7 +20,7 @@ 8 common creat sys_creat 9 common link sys_link 10 common unlink sys_unlink -11 nospu execve sys_execve compat_sys_execve +11 nospu execve sys_execve 12 common chdir sys_chdir 13 32 time sys_time32 13 64 time sys_time @@ -460,7 +460,7 @@ 359 common getrandom sys_getrandom 360 common memfd_create sys_memfd_create 361 common bpf sys_bpf -362 nospu execveat sys_execveat compat_sys_execveat +362 nospu execveat sys_execveat 363 32 switch_endian sys_ni_syscall 363 64 switch_endian sys_switch_endian 363 spu switch_endian sys_ni_syscall diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl index bfdcb763395735..bd2275db2026ea 100644 --- a/arch/s390/kernel/syscalls/syscall.tbl +++ b/arch/s390/kernel/syscalls/syscall.tbl @@ -18,7 +18,7 @@ 8 common creat sys_creat sys_creat 9 common link sys_link sys_link 10 common unlink sys_unlink sys_unlink -11 common execve sys_execve compat_sys_execve +11 common execve sys_execve sys_execve 12 common chdir sys_chdir sys_chdir 13 32 time - sys_time32 14 common mknod sys_mknod sys_mknod @@ -361,7 +361,7 @@ 351 common bpf sys_bpf sys_bpf 352 common s390_pci_mmio_write sys_s390_pci_mmio_write sys_s390_pci_mmio_write 353 common s390_pci_mmio_read sys_s390_pci_mmio_read sys_s390_pci_mmio_read -354 common execveat sys_execveat compat_sys_execveat +354 common execveat sys_execveat sys_execveat 355 common userfaultfd sys_userfaultfd sys_userfaultfd 356 common membarrier sys_membarrier sys_membarrier 357 common recvmmsg sys_recvmmsg compat_sys_recvmmsg_time32 diff --git a/arch/sparc/kernel/syscalls.S b/arch/sparc/kernel/syscalls.S index db42b4fb370844..70463972152a92 100644 --- a/arch/sparc/kernel/syscalls.S +++ b/arch/sparc/kernel/syscalls.S @@ -16,12 +16,12 @@ sys64_execveat: sunos_execv: mov %g0, %o2 sys32_execve: - set compat_sys_execve, %g1 + set sys_execve, %g1 jmpl %g1, %g0 flushw sys32_execveat: - set compat_sys_execveat, %g1 + set sys_execveat, %g1 jmpl %g1, %g0 flushw #endif diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl index d8f8a1a69ed11f..2b1eccd3f8f697 100644 --- a/arch/x86/entry/syscalls/syscall_32.tbl +++ b/arch/x86/entry/syscalls/syscall_32.tbl @@ -22,7 +22,7 @@ 8 i386 creat sys_creat 9 i386 link sys_link 10 i386 unlink sys_unlink -11 i386 execve sys_execve compat_sys_execve +11 i386 execve sys_execve 12 i386 chdir sys_chdir 13 i386 time sys_time32 14 i386 mknod sys_mknod @@ -369,7 +369,7 @@ 355 i386 getrandom sys_getrandom 356 i386 memfd_create sys_memfd_create 357 i386 bpf sys_bpf -358 i386 execveat sys_execveat compat_sys_execveat +358 i386 execveat sys_execveat 359 i386 socket sys_socket 360 i386 socketpair sys_socketpair 361 i386 bind sys_bind diff --git a/fs/exec.c b/fs/exec.c index 354fdaa536ae7d..94107eceda8a67 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -386,34 +386,25 @@ static int bprm_mm_init(struct linux_binprm *bprm) return err; } -struct user_arg_ptr { -#ifdef CONFIG_COMPAT - bool is_compat; -#endif - union { - const char __user *const __user *native; -#ifdef CONFIG_COMPAT - const compat_uptr_t __user *compat; -#endif - } ptr; -}; - -static const char __user *get_user_arg_ptr(struct user_arg_ptr argv, int nr) +static const char __user * +get_user_arg_ptr(const char __user *const __user *argv, int nr) { const char __user *native; #ifdef CONFIG_COMPAT - if (unlikely(argv.is_compat)) { + if (in_compat_syscall()) { + const compat_uptr_t __user *compat_argv = + compat_ptr((unsigned long)argv); compat_uptr_t compat; - if (get_user(compat, argv.ptr.compat + nr)) + if (get_user(compat, compat_argv + nr)) return ERR_PTR(-EFAULT); return compat_ptr(compat); } #endif - if (get_user(native, argv.ptr.native + nr)) + if (get_user(native, argv + nr)) return ERR_PTR(-EFAULT); return native; @@ -422,11 +413,11 @@ static const char __user *get_user_arg_ptr(struct user_arg_ptr argv, int nr) /* * count() counts the number of strings in array ARGV. */ -static int count(struct user_arg_ptr argv, int max) +static int count(const char __user *const __user *argv, int max) { int i = 0; - if (argv.ptr.native != NULL) { + if (argv) { for (;;) { const char __user *p = get_user_arg_ptr(argv, i); @@ -449,7 +440,8 @@ static int count(struct user_arg_ptr argv, int max) } static int prepare_arg_pages(struct linux_binprm *bprm, - struct user_arg_ptr argv, struct user_arg_ptr envp) + const char __user *const __user *argv, + const char __user *const __user *envp) { unsigned long limit, ptr_size; @@ -497,7 +489,7 @@ static int prepare_arg_pages(struct linux_binprm *bprm, * processes's memory to the new process's stack. The call to get_user_pages() * ensures the destination page is created and not swapped out. */ -static int copy_strings(int argc, struct user_arg_ptr argv, +static int copy_strings(int argc, const char __user *const __user *argv, struct linux_binprm *bprm) { struct page *kmapped_page = NULL; @@ -1815,10 +1807,10 @@ static int exec_binprm(struct linux_binprm *bprm) return 0; } -static int __do_execveat(int fd, struct filename *filename, - struct user_arg_ptr argv, - struct user_arg_ptr envp, - int flags, struct file *file) +int do_execveat(int fd, struct filename *filename, + const char __user *const __user *argv, + const char __user *const __user *envp, + int flags, struct file *file) { char *pathbuf = NULL; struct linux_binprm *bprm; @@ -1969,17 +1961,6 @@ static int __do_execveat(int fd, struct filename *filename, return retval; } -int do_execveat(int fd, struct filename *filename, - const char __user *const __user *__argv, - const char __user *const __user *__envp, - int flags, struct file *file) -{ - struct user_arg_ptr argv = { .ptr.native = __argv }; - struct user_arg_ptr envp = { .ptr.native = __envp }; - - return __do_execveat(fd, filename, argv, envp, flags, file); -} - void set_binfmt(struct linux_binfmt *new) { struct mm_struct *mm = current->mm; @@ -2024,40 +2005,28 @@ SYSCALL_DEFINE5(execveat, return do_execveat(fd, name, argv, envp, flags, NULL); } -#ifdef CONFIG_COMPAT -static int do_compat_execve(int fd, struct filename *filename, - const compat_uptr_t __user *__argv, - const compat_uptr_t __user *__envp, - int flags) -{ - struct user_arg_ptr argv = { - .is_compat = true, - .ptr.compat = __argv, - }; - struct user_arg_ptr envp = { - .is_compat = true, - .ptr.compat = __envp, - }; - - return __do_execveat(fd, filename, argv, envp, flags, NULL); -} - +/* + * x32 syscalls are listed in the same table as x86_64 ones, so we need to + * define compat syscalls that are exactly the same as the native version for + * the syscall table machinery to work. Sigh.. + */ +#ifdef CONFIG_X86_X32 COMPAT_SYSCALL_DEFINE3(execve, const char __user *, filename, - const compat_uptr_t __user *, argv, - const compat_uptr_t __user *, envp) + const char __user *const __user *, argv, + const char __user *const __user *, envp) { - return do_compat_execve(AT_FDCWD, getname(filename), argv, envp, 0); + return do_execveat(AT_FDCWD, getname(filename), argv, envp, 0, NULL); } COMPAT_SYSCALL_DEFINE5(execveat, int, fd, const char __user *, filename, - const compat_uptr_t __user *, argv, - const compat_uptr_t __user *, envp, + const char __user *const __user *, argv, + const char __user *const __user *, envp, int, flags) { int lookup_flags = (flags & AT_EMPTY_PATH) ? LOOKUP_EMPTY : 0; struct filename *name = getname_flags(filename, lookup_flags, NULL); - return do_compat_execve(fd, name, argv, envp, flags); + return do_execveat(fd, name, argv, envp, flags, NULL); } -#endif +#endif /* CONFIG_X86_X32 */ diff --git a/include/linux/compat.h b/include/linux/compat.h index e90100c0de72e4..5e8f6a588e0d43 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -752,10 +752,6 @@ asmlinkage long compat_sys_recvmsg(int fd, struct compat_msghdr __user *msg, asmlinkage long compat_sys_keyctl(u32 option, u32 arg2, u32 arg3, u32 arg4, u32 arg5); -/* arch/example/kernel/sys_example.c */ -asmlinkage long compat_sys_execve(const char __user *filename, const compat_uptr_t __user *argv, - const compat_uptr_t __user *envp); - /* mm/fadvise.c: No generic prototype for fadvise64_64 */ /* mm/, CONFIG_MMU only */ @@ -806,9 +802,6 @@ asmlinkage ssize_t compat_sys_process_vm_writev(compat_pid_t pid, const struct compat_iovec __user *lvec, compat_ulong_t liovcnt, const struct compat_iovec __user *rvec, compat_ulong_t riovcnt, compat_ulong_t flags); -asmlinkage long compat_sys_execveat(int dfd, const char __user *filename, - const compat_uptr_t __user *argv, - const compat_uptr_t __user *envp, int flags); asmlinkage ssize_t compat_sys_preadv2(compat_ulong_t fd, const struct compat_iovec __user *vec, compat_ulong_t vlen, u32 pos_low, u32 pos_high, rwf_t flags); diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h index f4a01305d9a65c..c639d04a094b8b 100644 --- a/include/uapi/asm-generic/unistd.h +++ b/include/uapi/asm-generic/unistd.h @@ -640,7 +640,7 @@ __SC_COMP(__NR_keyctl, sys_keyctl, compat_sys_keyctl) #define __NR_clone 220 __SYSCALL(__NR_clone, sys_clone) #define __NR_execve 221 -__SC_COMP(__NR_execve, sys_execve, compat_sys_execve) +__SYSCALL(__NR_execve, sys_execve) #define __NR3264_mmap 222 __SC_3264(__NR3264_mmap, sys_mmap2, sys_mmap) @@ -751,7 +751,7 @@ __SYSCALL(__NR_memfd_create, sys_memfd_create) #define __NR_bpf 280 __SYSCALL(__NR_bpf, sys_bpf) #define __NR_execveat 281 -__SC_COMP(__NR_execveat, sys_execveat, compat_sys_execveat) +__SYSCALL(__NR_execveat, sys_execveat) #define __NR_userfaultfd 282 __SYSCALL(__NR_userfaultfd, sys_userfaultfd) #define __NR_membarrier 283 diff --git a/tools/include/uapi/asm-generic/unistd.h b/tools/include/uapi/asm-generic/unistd.h index 3a3201e4618ef8..a6dbc8af8bd577 100644 --- a/tools/include/uapi/asm-generic/unistd.h +++ b/tools/include/uapi/asm-generic/unistd.h @@ -640,7 +640,7 @@ __SC_COMP(__NR_keyctl, sys_keyctl, compat_sys_keyctl) #define __NR_clone 220 __SYSCALL(__NR_clone, sys_clone) #define __NR_execve 221 -__SC_COMP(__NR_execve, sys_execve, compat_sys_execve) +__SYSCALL(__NR_execve, sys_execve) #define __NR3264_mmap 222 __SC_3264(__NR3264_mmap, sys_mmap2, sys_mmap) @@ -751,7 +751,7 @@ __SYSCALL(__NR_memfd_create, sys_memfd_create) #define __NR_bpf 280 __SYSCALL(__NR_bpf, sys_bpf) #define __NR_execveat 281 -__SC_COMP(__NR_execveat, sys_execveat, compat_sys_execveat) +__SYSCALL(__NR_execveat, sys_execveat) #define __NR_userfaultfd 282 __SYSCALL(__NR_userfaultfd, sys_userfaultfd) #define __NR_membarrier 283 diff --git a/tools/perf/arch/powerpc/entry/syscalls/syscall.tbl b/tools/perf/arch/powerpc/entry/syscalls/syscall.tbl index 35b61bfc1b1ae9..42bf8b461a0ed6 100644 --- a/tools/perf/arch/powerpc/entry/syscalls/syscall.tbl +++ b/tools/perf/arch/powerpc/entry/syscalls/syscall.tbl @@ -18,7 +18,7 @@ 8 common creat sys_creat 9 common link sys_link 10 common unlink sys_unlink -11 nospu execve sys_execve compat_sys_execve +11 nospu execve sys_execve sys_execve 12 common chdir sys_chdir 13 32 time sys_time32 13 64 time sys_time @@ -454,7 +454,7 @@ 359 common getrandom sys_getrandom 360 common memfd_create sys_memfd_create 361 common bpf sys_bpf -362 nospu execveat sys_execveat compat_sys_execveat +362 nospu execveat sys_execveat sys_execveat 363 32 switch_endian sys_ni_syscall 363 64 switch_endian ppc_switch_endian 363 spu switch_endian sys_ni_syscall diff --git a/tools/perf/arch/s390/entry/syscalls/syscall.tbl b/tools/perf/arch/s390/entry/syscalls/syscall.tbl index b38d48464368dc..f3c16f2d9746ac 100644 --- a/tools/perf/arch/s390/entry/syscalls/syscall.tbl +++ b/tools/perf/arch/s390/entry/syscalls/syscall.tbl @@ -18,7 +18,7 @@ 8 common creat sys_creat compat_sys_creat 9 common link sys_link compat_sys_link 10 common unlink sys_unlink compat_sys_unlink -11 common execve sys_execve compat_sys_execve +11 common execve sys_execve sys_execve 12 common chdir sys_chdir compat_sys_chdir 13 32 time - compat_sys_time 14 common mknod sys_mknod compat_sys_mknod @@ -361,7 +361,7 @@ 351 common bpf sys_bpf compat_sys_bpf 352 common s390_pci_mmio_write sys_s390_pci_mmio_write compat_sys_s390_pci_mmio_write 353 common s390_pci_mmio_read sys_s390_pci_mmio_read compat_sys_s390_pci_mmio_read -354 common execveat sys_execveat compat_sys_execveat +354 common execveat sys_execveat sys_execveat 355 common userfaultfd sys_userfaultfd sys_userfaultfd 356 common membarrier sys_membarrier sys_membarrier 357 common recvmmsg sys_recvmmsg compat_sys_recvmmsg
The only differenence betweeen the compat exec* syscalls and their native versions is that compat_ptr sign extension, and the fact that the pointer arithmetics for the two dimensional arrays needs to use the compat pointer size. Instead of the compat wrappers and the struct user_arg_ptr machinery just use in_compat_syscall() to do the right thing for the compat case deep inside get_user_arg_ptr(). Signed-off-by: Christoph Hellwig <hch@lst.de> --- arch/arm64/include/asm/unistd32.h | 4 +- arch/mips/kernel/syscalls/syscall_n32.tbl | 4 +- arch/mips/kernel/syscalls/syscall_o32.tbl | 4 +- arch/parisc/kernel/syscalls/syscall.tbl | 4 +- arch/powerpc/kernel/syscalls/syscall.tbl | 4 +- arch/s390/kernel/syscalls/syscall.tbl | 4 +- arch/sparc/kernel/syscalls.S | 4 +- arch/x86/entry/syscalls/syscall_32.tbl | 4 +- fs/exec.c | 89 ++++++------------- include/linux/compat.h | 7 -- include/uapi/asm-generic/unistd.h | 4 +- tools/include/uapi/asm-generic/unistd.h | 4 +- .../arch/powerpc/entry/syscalls/syscall.tbl | 4 +- .../perf/arch/s390/entry/syscalls/syscall.tbl | 4 +- 14 files changed, 53 insertions(+), 91 deletions(-)