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2005-11-07[PATCH] uml: separate libc-dependent early initializationJeff Dike
The serial UML OS-abstraction layer patch (um/kernel dir). This moves all systemcalls from main.c file under os-Linux dir and joins mem.c and um_arch.c files. Signed-off-by: Gennady Sharapov <Gennady.V.Sharapov@intel.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07[PATCH] uml: separate libc-dependent uaccess codeGennady Sharapov
The serial UML OS-abstraction layer patch (um/kernel dir). This moves all systemcalls from uaccess_user.c file under os-Linux dir Signed-off-by: Gennady Sharapov <Gennady.V.Sharapov@intel.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07[PATCH] uml: improve stub debuggingJeff Dike
Add some more debugging information when a stub does something unexpected, usually segfaulting. Now, it dumps out the stub's registers as well as the signal. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30[PATCH] jiffies_64 cleanupThomas Gleixner
Define jiffies_64 in kernel/timer.c rather than having 24 duplicated defines in each architecture. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-29[PATCH] mm: split page table lockHugh Dickins
Christoph Lameter demonstrated very poor scalability on the SGI 512-way, with a many-threaded application which concurrently initializes different parts of a large anonymous area. This patch corrects that, by using a separate spinlock per page table page, to guard the page table entries in that page, instead of using the mm's single page_table_lock. (But even then, page_table_lock is still used to guard page table allocation, and anon_vma allocation.) In this implementation, the spinlock is tucked inside the struct page of the page table page: with a BUILD_BUG_ON in case it overflows - which it would in the case of 32-bit PA-RISC with spinlock debugging enabled. Splitting the lock is not quite for free: another cacheline access. Ideally, I suppose we would use split ptlock only for multi-threaded processes on multi-cpu machines; but deciding that dynamically would have its own costs. So for now enable it by config, at some number of cpus - since the Kconfig language doesn't support inequalities, let preprocessor compare that with NR_CPUS. But I don't think it's worth being user-configurable: for good testing of both split and unsplit configs, split now at 4 cpus, and perhaps change that to 8 later. There is a benefit even for singly threaded processes: kswapd can be attacking one part of the mm while another part is busy faulting. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-29[PATCH] mm: uml kill unusedHugh Dickins
In worrying over the various pte operations in different architectures, I came across some unused functions in UML: remove mprotect_kernel_vm, protect_vm_page and addr_pte. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-29[PATCH] mm: uml pte atomicityHugh Dickins
There's usually a good reason when a pte is examined without the lock; but it makes me nervous when the pointer is dereferenced more than once. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-29[PATCH] mm: arches skip ptlockHugh Dickins
Convert those few architectures which are calling pud_alloc, pmd_alloc, pte_alloc_map on a user mm, not to take the page_table_lock first, nor drop it after. Each of these can continue to use pte_alloc_map, no need to change over to pte_alloc_map_lock, they're neither racy nor swappable. In the sparc64 io_remap_pfn_range, flush_tlb_range then falls outside of the page_table_lock: that's okay, on sparc64 it's like flush_tlb_mm, and that has always been called from outside of page_table_lock in dup_mmap. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-28[PATCH] gfp_t: remaining bits of arch/*Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-04[PATCH] uml: Fix sysrq-r support for skas modeAllan Graves
The old code had the IP and SP coming from the registers in the thread struct, which are completely wrong since those are the userspace registers. This fixes that by pulling the correct values from the jmp_buf in which the kernel state of each thread is stored. Signed-off-by: Allan Graves <allan.graves@oracle.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-30[PATCH] uml: clear SKAS0/3 flags when running in TT modePaolo 'Blaisorblade' Giarrusso
SEGV_MAYBE_FIXABLE tests ptrace_faultinfo, and depends on it being 1 only in SKAS3 mode, while currently when running with mode=tt it will be 1 anyway. Fix this, and do the same for proc_mm. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-30[PATCH] uml: fix page faults in SKAS3 mode.Paolo 'Blaisorblade' Giarrusso
I hadn't been running a SKAS3 host when testing the "uml: fix hang in TT mode on fault" patch (commit 546fe1cbf91d4d62e3849517c31a2327c992e5c5), and I didn't think enough to the missing trap_no in SKAS3 mode. In fact, the resulting kernel doesn't work at all in SKAS3 mode. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-30[PATCH] useless linux/irq.h includes (arch/um)Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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 <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-22[PATCH] uml: use GFP_ATOMIC for allocations under spinlocks.Paolo 'Blaisorblade' Giarrusso
setup_initial_poll is only called with sigio_lock() held, so use appropriate allocation. Also, parse_chan() can also be called when holding a spinlock (see line_open() -> parse_chan_pair()). I have sporadic problems (spinlock taken twice, with spinlock debugging on UP) which could be caused by a sequence like "take spinlock, alloc and go to sleep, take again the spinlock in the other thread". Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-22[PATCH] uml: Fix GFP_ flags usagePaolo 'Blaisorblade' Giarrusso
GFP_ATOMIC | GFP_KERNEL is meaningless and won't work. Actually it never worked, even in 2.4. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-22[PATCH] uml: avoid fixing faults while atomicPaolo 'Blaisorblade' Giarrusso
Following i386, we should maybe refuse trying to fault in pages when we're doing atomic operations, because to handle the fault we could need to take already taken spinlocks. Also, if we're doing an atomic operation (in the sense of in_atomic()) we're surely in kernel mode and we're surely going to handle adequately the failed fault, so it's safe to behave this way. Currently, on UML SMP is rarely used, and we don't support PREEMPT, so this is unlikely to create problems right now, but it might in the future. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-22[PATCH] uml: fix condition in tlb flushPaolo 'Blaisorblade' Giarrusso
Avoid setting w = 0 twice. Spotted this (trivial) thing which is needed for another patch. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-22[PATCH] uml: fix hang in TT mode on faultPaolo 'Blaisorblade' Giarrusso
The current code doesn't handle well general protection faults on the host - it thinks that cr2 is always the address of a page fault. While actually, on general protection faults, that address is not accessible, so we'd better assume we couldn't satisfy the fault. Currently instead we think we've fixed it, so we go back, retry the instruction and fault again endlessly. This leads to the kernel hanging when doing copy_from_user(dest, -1, ...) in TT mode, since reading *(-1) causes a GFP, and we don't support kernel preemption. Thanks to Luo Xin for testing UML with LTP and reporting the failures he got. Cc: Luo Xin <luothing@sina.com> Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-22[PATCH] strlcat: use for uml umid.cPaolo 'Blaisorblade' Giarrusso
Simplify the code by using strlcat() instead of strncat() and manual appending. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-22[PATCH] uml: don't remove umid files in conflict casePaolo 'Blaisorblade' Giarrusso
Only remove the UML pidfile and management socket if we created them. Currently in case two UMLs are started with the same umid, the second will remove the first's ones. Probably we should also panic() at that point, not sure however. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-21[PATCH] uml: fix compile warning after consolidation patchPaolo 'Blaisorblade' Giarrusso
The header declaring this function wasn't included, so the function declaration was totally bogus wrt. the proto - even if this wasn't going to fail at all. It was so bad that the compile warning I got was "control reaches end of non-void function", i.e. missing return. Actually, this has been there for ages, the consolidation patch just added the warning which was needed to clean it up. Nice. Really. Cc: Allan Graves <allan.graves@gmail.com> Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-21[PATCH] uml: fix uname output on 32-bit binary on 64-bit hostPaolo 'Blaisorblade' Giarrusso
Translate uname output taken from the host if needed. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-21[PATCH] uml: remove verify_area_{tt,skas}Paolo 'Blaisorblade' Giarrusso
When removing verify_area, verify_area_{tt,skas} were forgotten. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-17[PATCH] uml: merge mem_user.c and mem.cJeff Dike
The serial UML OS-abstraction layer patch (um/kernel dir). This joins mem_user.c and mem.c files. Signed-off-by: Gennady Sharapov <Gennady.V.Sharapov@intel.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-17[PATCH] uml: move libc code out of mem_user.c and tempfile.cJeff Dike
The serial UML OS-abstraction layer patch (um/kernel dir). This moves all system calls from mem_user.c and tempfile.c files under os-Linux dir. Signed-off-by: Gennady Sharapov <Gennady.V.Sharapov@intel.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-17[PATCH] uml: preserve errno in error pathsJeff Dike
The poster child for this patch is the third tuntap_user hunk. When an ioctl fails, it properly closes the opened file descriptor and returns. However, the close resets errno to 0, and the 'return errno' that follows returns 0 rather than the value that ioctl set. This caused the caller to believe that the device open succeeded and had opened file descriptor 0, which caused no end of interesting behavior. The rest of this patch is a pass through the UML sources looking for places where errno could be reset before being passed back out. A common culprit is printk, which could call write, being called before errno is returned. In some cases, where the code ends up being much smaller, I just deleted the printk. There was another case where a caller of run_helper looked at errno after a failure, rather than the return value of run_helper, which was the errno value that it wanted. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-17[PATCH] uml: breakpoint an arbitrary threadJeff Dike
This patch implements a stack trace for a thread, not unlike sysrq-t does. The advantage to this is that a break point can be placed on showreqs, so that upon showing the stack, you jump immediately into the debugger. While sysrq-t does the same thing, sysrq-t shows *all* threads stacks. It also doesn't work right now. In the future, I thought it might be acceptable to make this show all pids stacks, but perhaps leaving well enough alone and just using sysrq-t would be okay. For now, upon receiving the stack command, UML switches context to that thread, dumps its registers, and then switches context back to the original thread. Since UML compacts all threads into one of 4 host threads, this sort of mechanism could be expanded in the future to include other debugging helpers that sysrq does not cover. Note by jdike - The main benefit to this is that it brings an arbitrary thread back into context, where it can be examined by gdb. The fact that it dumps it stack is secondary. This provides the capability to examine a sleeping thread, which has existed in tt mode, but not in skas mode until now. Also, the other threads, that sysrq doesn't cover, can be gdb-ed directly anyway. Signed-off-by: Allan Graves<allan.graves@gmail.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-17[PATCH] uml: _switch_to code consolidationJeff Dike
This patch moves code that is in both switch_to_tt and switch_to_skas to the top level _switch_to function, keeping us from duplicating code. It is required for the stack trace patch to work properly. Signed-off-by: Allan Graves <allan.graves@gmail.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-10[PATCH] uml: avoid already done dirtyingPaolo 'Blaisorblade' Giarrusso
The PTE returned from handle_mm_fault is already marked as dirty and accessed if needed. Also, since this is not set with set_pte() (which sets NEWPAGE and NEWPROT as needed), this wouldn't work anyway. This version has been updated and fixed, thanks to some feedback from Jeff Dike. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-10[PATCH] uml: fix fault handler on writePaolo 'Blaisorblade' Giarrusso
The UML fault handler was recently changed to enforce PROT_NONE protections, by requiring VM_READ or VM_EXEC on VMA's. However, by mistake, things were changed such that VM_READ is always checked, also on write faults; so a VMA mapped with only PROT_WRITE is not readable (unless it's prefaulted with MAP_POPULATE or with a write), which is different from i386. Discovered while testing remap_file_pages protection support. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-10[PATCH] uml: inline mk_pte and various friendsPaolo 'Blaisorblade' Giarrusso
Turns out that, for UML, a *lot* of VM-related trivial functions are not inlined but rather normal functions. In other sections of UML code, this is justified by having files which interact with the host and cannot therefore include kernel headers, but in this case there's no such justification. I've had to turn many of them to macros because of missing declarations. While doing this, I've decided to reuse some already existing macros. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-10[PATCH] i386 / uml: add dwarf sections to static link scriptPaolo 'Blaisorblade' Giarrusso
Inside the linker script, insert the code for DWARF debug info sections. This may help GDB'ing a Uml binary. Actually, it seems that ld is able to guess what I added correctly, but normal linker scripts include this section so it should be correct anyway adding it. On request by Sam Ravnborg <sam@ravnborg.org>, I've added it to asm-generic/vmlinux.lds.s. I've also moved there the stabs debug section, used the new macro in i386 linker script and added DWARF debug section to that. In the truth, I've not been able to verify the difference in GDB behaviour after this change (I've seen large improvements with another patch). This may depend on my binutils version, older one may have worse defaults. However, this section is present in normal linker script, so add it at least for the sake of cleanness. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Acked-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-09Merge master.kernel.org:/pub/scm/linux/kernel/git/sam/kbuild Linus Torvalds
2005-09-09kbuild: um fix so it compile with generic asm-offsets.h supportSam Ravnborg
um has it own set of files for asm-offsets. So for now the gen-asm-offset macro is just duplicated in the um Makefile. This may well be the final solution since um is a bit special compared to other architectures - time will tell. Also added a dummy arch/um/kernel/asm-offsets.h file to keep kbuild happy. Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2005-09-09[PATCH] uaccess.h annotations (uml)viro@ZenIV.linux.org.uk
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-07[PATCH] bogus #if (arch/um/kernel/mem.c)viro@ZenIV.linux.org.uk
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] uml: fix x86_64 page leakJeff Dike
We were leaking pmd pages when 3_LEVEL_PGTABLES was enabled. This fixes that. Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] uml: skas0 stubs now check system call return valuesBodo Stroesser
Change syscall-stub's data to include a "expected retval". Stub now checks syscalls retval and aborts execution of syscall list, if retval != expected retval. run_syscall_stub prints the data of the failed syscall, using the data pointer and retval written by the stub to the beginning of the stack. one_syscall_stub is removed, to simplify code, because only some instructions are saved by one_syscall_stub, no host-syscall. Using the stub with additional data (modify_ldt via stub) is prepared also. Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] uml: increase granularity of host capability checkingBodo Stroesser
This change enables SKAS0/SKAS3 to work with all combinations of /proc/mm and PTRACE_FAULTINFO being available or not. Also it changes the initialization of proc_mm and ptrace_faultinfo slightly, to ease forcing SKAS0 on a patched host. Forcing UML to run without /proc/mm or PTRACE_FAULTINFO by cmdline parameter can be implemented with a setup resetting the related variable. Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] uml: move libc-dependent startup and signal codeGennady Sharapov
The serial UML OS-abstraction layer patch (um/kernel dir). This moves all systemcalls from process.c file under os-Linux dir and join process.c and process_kern.c files. Signed-off-by: Gennady Sharapov <gennady.v.sharapov@intel.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] uml: use host AIO supportJeff Dike
This patch makes UML use host AIO support when it (and /usr/include/linux/aio_abi.h) are present. This is only the support, with no consumers - a consumer is coming in the next patch. Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] uml: system call path cleanupJeff Dike
This merges two sets of files which had no business being split apart in the first place. Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] uml: TLB operation batchingJeff Dike
This adds VM op batching to skas0. Rather than having a context switch to and from the userspace stub for each address space change, we write a number of operations to the stub data page and invoke a different stub which loops over them and executes them all in one go. The operations are stored as [ system call number, arg1, arg2, ... ] tuples. The set is terminated by a system call number of 0. Single operations, i.e. page faults, are handled in the old way, since that is slightly more efficient. For a kernel build, a minority (~1/4) of the operations are part of a set. These sets averaged ~100 in length, so for this quarter, the context switching overhead is greatly reduced. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] uml: remove duplicated exportsJeff Dike
Al Viro <viro@parcelfarce.linux.theplanet.co.uk> spotted a bunch of duplicated exports - this removes them. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] uml: fault handler micro-cleanupsPaolo 'Blaisorblade' Giarrusso
Avoid chomping low bits of address for functions doing it by themselves, fix whitespace, add a correctness checking. I did this for remap-file-pages protection support, it was useful on its own too. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] uml: workaround GDB problems on debuggingPaolo 'Blaisorblade' Giarrusso
Apparently, GDB gets confused when we do an execvp() on ourselves. Since it's simply done to allocate further space for command line arguments (which we'll use to allow gathering the startup command line for guest processes through the host), allow the user to disable that to get a debuggable UML binary. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] uml: remove debugging code from page fault pathJeff Dike
This eliminates the segfault info ring buffer, which added a system call to each page fault, and which hadn't been useful for debugging in ages. Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-29[PATCH] convert signal handling of NODEFER to act like other Unix boxes.Steven Rostedt
It has been reported that the way Linux handles NODEFER for signals is not consistent with the way other Unix boxes handle it. I've written a program to test the behavior of how this flag affects signals and had several reports from people who ran this on various Unix boxes, confirming that Linux seems to be unique on the way this is handled. The way NODEFER affects signals on other Unix boxes is as follows: 1) If NODEFER is set, other signals in sa_mask are still blocked. 2) If NODEFER is set and the signal is in sa_mask, then the signal is still blocked. (Note: this is the behavior of all tested but Linux _and_ NetBSD 2.0 *). The way NODEFER affects signals on Linux: 1) If NODEFER is set, other signals are _not_ blocked regardless of sa_mask (Even NetBSD doesn't do this). 2) If NODEFER is set and the signal is in sa_mask, then the signal being handled is not blocked. The patch converts signal handling in all current Linux architectures to the way most Unix boxes work. Unix boxes that were tested: DU4, AIX 5.2, Irix 6.5, NetBSD 2.0, SFU 3.5 on WinXP, AIX 5.3, Mac OSX, and of course Linux 2.6.13-rcX. * NetBSD was the only other Unix to behave like Linux on point #2. The main concern was brought up by point #1 which even NetBSD isn't like Linux. So with this patch, we leave NetBSD as the lonely one that behaves differently here with #2. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-18[PATCH] uml: fix a crash under screenJeff Dike
Running UML inside a detached screen delivers SIGWINCH when UML is not expecting it. This patch ignores them. Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>