path: root/arch/um/Makefile-i386
AgeCommit message (Collapse)Author
2006-06-05[PATCH] uml: add -ffreestanding to CFLAGSJeff Dike
From: Jeff Dike <> This fixes the undefined reference to strcpy seen when building modules on i386. Tracked down by Al Viro. Signed-off-by: Jeff Dike <> Cc: Paolo 'Blaisorblade' Giarrusso <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
2005-11-13[PATCH] uml: fixups for "reuse i386 cpu-specific tuning"Paolo 'Blaisorblade' Giarrusso
A few fixups - show the new submenu only for x86 subarchitecture (it does not make sense to show it for x86_64 users) and remove X86_CMPXCHG, which is now a duplicate of Kconfig.i386, even though Kconfig doesn't complain (we also miss the dependency on !M386 CPU). Signed-off-by: Paolo 'Blaisorblade' Giarrusso <> Acked-by: Jeff Dike <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
2005-11-07[PATCH] uml: build host-binaries with the native host arch againPaolo 'Blaisorblade' Giarrusso
This patch reverts back the changes to HOSTCFLAGS and HOSTLDFLAGS When we were building complete binaries to get constants (such as ptrace register layout on stack) from host userspace headers, we needed to make the arch for building HOST binaries match our one: i.e. on a 64bit system compiling 32bit binaries, we compile 32-bit hostprogs and need, say, 32-bit ncurses. Now we can revert that - that avoids problem with, say, menuconfig and ncurses, on a system which can't compile well 32-bit programs. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <> Cc: Jeff Dike <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
2005-10-30[PATCH] uml: remove old UM_FASTCALL, and make the thing work againPaolo 'Blaisorblade' Giarrusso
This was used in the old dark age of 2.4, ARCH_CFLAGS doesn't work any more since some time, and UM_FASTCALL was never used in 2.6. Instead, reintroduce the thing more properly now, directly in include/asm-um/linkage.h. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
2005-10-30[PATCH] uml: reuse i386 cpu-specific tuningPaolo 'Blaisorblade' Giarrusso
Make UML share the underlying cpu-specific tuning done on i386. Actually, for now many config options aren't used a lot - but that can be done later. Also, UML relies on GCC optimization for things like memcpy and such more than i386, so specifying the correct -march and -mtune should be enough. Later, we may want to correct some other stuff. For instance, since FPU context switching, for us, is done (at least partially, i.e. between our kernelspace and userspace) by the host, we may allow usage of FPU operations by GCC. This doesn't hold for kernelspace vs. kernelspace, but we don't support preemption. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
2005-09-29[PATCH] uml makefiles sanitizedAl Viro
UML makefiles sanitized: - number of generated headers reduced to 2 (from user-offsets.c and kernel-offsets.c resp.). The rest is made constant and simply includes those two. - mk_... helpers are gone now that we don't need to generate these headers - arch/um/include2 removed since everything under arch/um/include/sysdep is constant now and symlink can point straight to source tree. - dependencies seriously simplified. Signed-off-by: Al Viro <> Signed-off-by: Linus Torvalds <>
2005-09-07[PATCH] lost chunk of "uml: build cleanups"
A piece of the UML stubs patch got lost - it has Killed STUBS_CFLAGS - it's not needed and the only remaining use had been gratitious - it only polluted CFLAGS in description and does remove it in arch/um/Makefile-x86_64, but forgets to do the same in i386 counterpart. Lost chunk follows: Signed-off-by: Al Viro <> Signed-off-by: Linus Torvalds <>
2005-07-27[PATCH] uml: readd missing define to arch/um/Makefile-i386Olaf Hering
scripts/ /Makefile: No such file or directory scripts/ kbuild: is included improperly the define was removed, but its still required to build some targets. Signed-off-by: Olaf Hering <> Cc: Paolo Giarrusso <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
2005-07-14[PATCH] uml: allow building as 32-bit binary on 64bit hostPaolo 'Blaisorblade' Giarrusso
This patch makes the command: make ARCH=um SUBARCH=i386 work on x86_64 hosts (with support for building 32-bit binaries). This is especially needed since 64-bit UMLs don't support 32-bit emulation for guest binaries, currently. This has been tested in all possible cases and works. Only exception is that I've built but not tested a 64-bit binary, because I hadn't a 64-bit filesystem available. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <> Cc: Jeff Dike <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
2005-07-07[PATCH] uml: skas0 - separate kernel address space on stock hostsJeff Dike
UML has had two modes of operation - an insecure, slow mode (tt mode) in which the kernel is mapped into every process address space which requires no host kernel modifications, and a secure, faster mode (skas mode) in which the UML kernel is in a separate host address space, which requires a patch to the host kernel. This patch implements something very close to skas mode for hosts which don't support skas - I'm calling this skas0. It provides the security of the skas host patch, and some of the performance gains. The two main things that are provided by the skas patch, /proc/mm and PTRACE_FAULTINFO, are implemented in a way that require no host patch. For the remote address space changing stuff (mmap, munmap, and mprotect), we set aside two pages in the process above its stack, one of which contains a little bit of code which can call mmap et al. To update the address space, the system call information (system call number and arguments) are written to the stub page above the code. The %esp is set to the beginning of the data, the %eip is set the the start of the stub, and it repeatedly pops the information into its registers and makes the system call until it sees a system call number of zero. This is to amortize the cost of the context switch across multiple address space updates. When the updates are done, it SIGSTOPs itself, and the kernel process continues what it was doing. For a PTRACE_FAULTINFO replacement, we set up a SIGSEGV handler in the child, and let it handle segfaults rather than nullifying them. The handler is in the same page as the mmap stub. The second page is used as the stack. The handler reads cr2 and err from the sigcontext, sticks them at the base of the stack in a faultinfo struct, and SIGSTOPs itself. The kernel then reads the faultinfo and handles the fault. A complication on x86_64 is that this involves resetting the registers to the segfault values when the process is inside the kill system call. This breaks on x86_64 because %rcx will contain %rip because you tell SYSRET where to return to by putting the value in %rcx. So, this corrupts $rcx on return from the segfault. To work around this, I added an arch_finish_segv, which on x86 does nothing, but which on x86_64 ptraces the child back through the sigreturn. This causes %rcx to be restored by sigreturn and avoids the corruption. Ultimately, I think I will replace this with the trick of having it send itself a blocked signal which will be unblocked by the sigreturn. This will allow it to be stopped just after the sigreturn, and PTRACE_SYSCALLed without all the back-and-forth of PTRACE_SYSCALLing it through sigreturn. This runs on a stock host, so theoretically (and hopefully), tt mode isn't needed any more. We need to make sure that this is better in every way than tt mode, though. I'm concerned about the speed of address space updates and page fault handling, since they involve extra round-trips to the child. We can amortize the round-trip cost for large address space updates by writing all of the operations to the data page and having the child execute them all at the same time. This will help fork and exec, but not page faults, since they involve only one page. I can't think of any way to help page faults, except to add something like PTRACE_FAULTINFO to the host. There is PTRACE_SIGINFO, but UML doesn't use siginfo for SIGSEGV (or anything else) because there isn't enough information in the siginfo struct to handle page faults (the faulting operation type is missing). Adding that would make PTRACE_SIGINFO a usable equivalent to PTRACE_FAULTINFO. As for the code itself: - The system call stub is in arch/um/kernel/sys-$(SUBARCH)/stub.S. It is put in its own section of the binary along with stub_segv_handler in arch/um/kernel/skas/process.c. This is manipulated with run_syscall_stub in arch/um/kernel/skas/mem_user.c. syscall_stub will execute any system call at all, but it's only used for mmap, munmap, and mprotect. - The x86_64 stub calls sigreturn by hand rather than allowing the normal sigreturn to happen, because the normal sigreturn is a SA_RESTORER in UML's address space provided by libc. Needless to say, this is not available in the child's address space. Also, it does a couple of odd pops before that which restore the stack to the state it was in at the time the signal handler was called. - There is a new field in the arch mmu_context, which is now a union. This is the pid to be manipulated rather than the /proc/mm file descriptor. Code which deals with this now checks proc_mm to see whether it should use the usual skas code or the new code. - userspace_tramp is now used to create a new host process for every UML process, rather than one per UML processor. It checks proc_mm and ptrace_faultinfo to decide whether to map in the pages above its stack. - start_userspace now makes CLONE_VM conditional on proc_mm since we need separate address spaces now. - switch_mm_skas now just sets userspace_pid[0] to the new pid rather than PTRACE_SWITCH_MM. There is an addition to userspace which updates its idea of the pid being manipulated each time around the loop. This is important on exec, when the pid will change underneath userspace(). - The stub page has a pte, but it can't be mapped in using tlb_flush because it is part of tlb_flush. This is why it's required for it to be mapped in by userspace_tramp. Other random things: - The stub section in is page aligned. This page is written out to the backing vm file in setup_physmem because it is mapped from there into user processes. - There's some confusion with TASK_SIZE now that there are a couple of extra pages that the process can't use. TASK_SIZE is considered by the elf code to be the usable process memory, which is reasonable, so it is decreased by two pages. This confuses the definition of USER_PGDS_IN_LAST_PML4, making it too small because of the rounding down of the uneven division. So we round it to the nearest PGDIR_SIZE rather than the lower one. - I added a missing PT_SYSCALL_ARG6_OFFSET macro. - um_mmu.h was made into a userspace-usable file. - proc_mm and ptrace_faultinfo are globals which say whether the host supports these features. - There is a bad interaction between the mm.nr_ptes check at the end of exit_mmap, stack randomization, and skas0. exit_mmap will stop freeing pages at the PGDIR_SIZE boundary after the last vma. If the stack isn't on the last page table page, the last pte page won't be freed, as it should be since the stub ptes are there, and exit_mmap will BUG because there is an unfreed page. To get around this, TASK_SIZE is set to the next lowest PGDIR_SIZE boundary and mm->nr_ptes is decremented after the calls to init_stub_pte. This ensures that we know the process stack (and all other process mappings) will be below the top page table page, and thus we know that mm->nr_ptes will be one too many, and can be decremented. Things that need fixing: - We may need better assurrences that the stub code is PIC. - The stub pte is set up in init_new_context_skas. - alloc_pgdir is probably the right place. Signed-off-by: Jeff Dike <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
2005-05-05[PATCH] uml: cross-build support : mk_threadAl Viro
mk_thread converted Signed-off-by: Al Viro <> Signed-off-by: Jeff Dike <> Cc: Paolo 'Blaisorblade' Giarrusso <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
2005-05-05[PATCH] uml: cross-build support: mk_scAl Viro
Ditto for mk_sc Signed-off-by: Al Viro <> Signed-off-by: Jeff Dike <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
2005-05-01[PATCH] uml: support AES i586 crypto driverPaolo 'Blaisorblade' Giarrusso
We want to make possible, for the user, to enable the i586 AES implementation. This requires a restructure. - Add a CONFIG_UML_X86 to notify that we are building a UML for i386. - Rename CONFIG_64_BIT to CONFIG_64BIT as is used for all other archs - Tell crypto/Kconfig that UML_X86 is as good as X86 - Tell it that it must exclude not X86_64 but 64BIT, which will give the same results. - Tell kbuild to descend down into arch/i386/crypto/ to build what's needed. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
2005-04-16Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!