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* [PATCH] uml: avoid warnings for diffent names for an unsigned quadwordPaolo 'Blaisorblade' Giarrusso2006-04-112-2/+2
| | | | | | | | | | | | | | Since on some 64-bit systems __u64 is rightfully defined to unsigned long and GCC recognizes anyway unsigned long and unsigned long long as different, fix some types back to being unsigned long long to avoid warnings and errors (for prototype mismatch) on those systems. Thanks to the report by Wesley Emeneker wesleyemeneker (at) google (dot) 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>
* [PATCH] uml: fix parallel make early failure on clean treePaolo 'Blaisorblade' Giarrusso2006-04-111-1/+2
| | | | | | | | | | | Parallel make failed once for me - fix this by adding the appropriate command (mkdir before creating a link in that dir). Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Acked-by: Sam Ravnborg <sam@ravnborg.org> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: local_irq_save, not local_save_flagsPaolo 'Blaisorblade' Giarrusso2006-04-111-1/+1
| | | | | | | | | | | The call to local_save_flags seems bogus since it is followed by local_irq_restore, and it's intended to lock the list from concurrent mconsole_interrupt invocations. 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>
* [PATCH] uml: fix big stack userPaolo 'Blaisorblade' Giarrusso2006-04-111-10/+13
| | | | | | | | | | | | | | | | Switch this proc from storing 4k of data (a whole path) on the stack to keeping it on the heap. Maybe it's not called in process context but only in early boot context (where in UML you have a normal process stack on the host) but just to be safe, fix it. While at it some little readability simplifications. 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>
* [PATCH] uml: fix failure path after conversionPaolo 'Blaisorblade' Giarrusso2006-04-111-5/+10
| | | | | | | | | | | | | | | Little fix for error paths in this code. - Some bug come from conversion to os-Linux (open() doesn't follow the kernel -errno return convention, while the old code called os_open_file() which followed it). This caused the wrong return code to be printed. - Then be more precise about what happened and do some whitespace fixes. 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>
* [PATCH] uml: fix hang on run_helper() failure on uml_netPaolo 'Blaisorblade' Giarrusso2006-04-112-6/+8
| | | | | | | | | | Fix an hang on a pipe when run_helper() fails when called by change_tramp() (i.e. when calling uml_net) - reproduced the bug and verified this fixes it. 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>
* [PATCH] uml: move outside spinlock call not needing itPaolo 'Blaisorblade' Giarrusso2006-04-111-1/+1
| | | | | | | | | | Move a call to kfree on a local variable out of a spinlock - there's no need to have it in. Done on a just merged 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>
* [PATCH] uml: support sparse for userspace filesPaolo 'Blaisorblade' Giarrusso2006-04-111-4/+2
| | | | | | | | | | | | | | Make sparse checker work for userspace files - it normally gets -nostdinc separately, so avoid having it for userspace files. Also, add -D$(SUBARCH) for multiarch hosts (i.e. AMD64 with compatibility headers). It works, the only problem is a bit of bogus warnings for system headers, but they're not too many. 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>
* [PATCH] uml: fix critical typo for TT modePaolo 'Blaisorblade' Giarrusso2006-04-112-2/+2
| | | | | | | | | | | Noticed this for a compilation-time warning, so I'm fixing it even for TT mode - this is not put_user, but copy_to_user, so we need a pointer to sp, not sp itself (we're trying to write the word pointed to by the "sp" var.). 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>
* [PATCH] uml: fix "extern-vs-static" proto conflict in TLS codePaolo 'Blaisorblade' Giarrusso2006-04-111-4/+0
| | | | | | | | | | Move the prototype from arch-generic to arch-specific includes because on x86_64 these functions are two static inlines. 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>
* [PATCH] uml: fix some double export warningsPaolo 'Blaisorblade' Giarrusso2006-04-113-10/+8
| | | | | | | | | Some functions are exported twice in current code - remove the excess export. 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>
* [PATCH] uml: fix format errorsPaolo 'Blaisorblade' Giarrusso2006-04-115-7/+7
| | | | | | | | | | Now that GCC warns about format errors, fix them. Nothing able to cause a crash, 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>
* [PATCH] uml: request format warnings to GCC for appropriate functionsPaolo 'Blaisorblade' Giarrusso2006-04-113-4/+8
| | | | | | | | | Add the format attribute to prototypes so GCC warns about improper usage. 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>
* [PATCH] uml: fix 2 harmless cast warnings for 64-bitPaolo 'Blaisorblade' Giarrusso2006-04-112-2/+3
| | | | | | | | | | | Fix two harmless warnings in 64-bit compilation (the 2nd doesn't trigger for now because of a missing __attribute((format)) for cow_printf, but next patches fix that). 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>
* [PATCH] uml: safe migration path to the correct V3 COW formatPaolo 'Blaisorblade' Giarrusso2006-04-111-15/+76
| | | | | | | | | | | | | | | | | - Correct the layout of all header versions - make all them well-specified for any external event. As we don't have 1-byte or 2-byte wide fields, the 32-bit layout (historical one) has no extra padding, so we can safely add __attribute__((packed)). - Add detection and reading of the broken 64-bit COW format which has been around for a while - to allow safe migration to the correct 32-bit format. Safe detection is possible, thanks to some luck with the existing format, and it works in practice. 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>
* [PATCH] uml: make 64-bit COW files compatible with 32-bit onesPaolo 'Blaisorblade' Giarrusso2006-04-111-1/+1
| | | | | | | | | | | | This is the minimal fix to make 64-bit UML binaries create 32-bit compatible COW files and read them. I've indeed tested that current code doesn't do this - the code gets SIGFPE for a division by a value read at the wrong place, where 0 is found. 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>
* [PATCH] uml: memory hotplug cleanupsJeff Dike2006-04-111-3/+1
| | | | | | | | | | | | | Change memory hotplug to use GFP_NOWAIT instead of GFP_ATOMIC, so that it will grab memory without sleeping, but doesn't try to use the emergency pools. A small list initialization suggested by Daniel Phillips - don't initialize lists which are just about to be list_add-ed. Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] UML: TLS fixletsJeff Dike2006-04-112-1/+2
| | | | | | | | | | | | Two small TLS fixes - arch/um/os-Linux/sys-i386/tls.c uses errno and -E* so it should include errno.h __setup_host_supports_tls returns 1, but as an initcall, it should return 0 Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: check for differences in host supportPaolo 'Blaisorblade' Giarrusso2006-03-317-5/+97
| | | | | | | | | | | | | | | | | | If running on a host not supporting TLS (for instance 2.4) we should report that cleanly to the user, instead of printing not comprehensible "error 5" for that. Additionally, i386 and x86_64 support different ranges for user_desc->entry_number, and we must account for that; we couldn't pass ourselves -1 because we need to override previously existing TLS descriptors which glibc has possibly set, so test at startup the range to use. x86 and x86_64 existing ranges are hardcoded. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: add arch_switch_to for newly forked threadPaolo 'Blaisorblade' Giarrusso2006-03-313-4/+25
| | | | | | | | | | | | Newly forked threads have no arch_switch_to_skas() called before their first run, because when schedule() switches to them they're resumed in the body of thread_wait() inside fork_handler() rather than in switch_threads() in switch_to_skas(). Compensate this missing call. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: tls support: hack to make it compile on any hostPaolo 'Blaisorblade' Giarrusso2006-03-314-11/+68
| | | | | | | | | | | Copy the definition of struct user_desc (with another name) for use by userspace sources (where we use the host headers, and we can't be sure about their content) to make sure UML compiles. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: implement {get,set}_thread_area for i386Paolo 'Blaisorblade' Giarrusso2006-03-3114-23/+470
| | | | | | | | | | | | | | | | | | | | | | Implement sys_[gs]et_thread_area and the corresponding ptrace operations for UML. This is the main chunk, additional parts follow. This implementation is now well tested and has run reliably for some time, and we've understood all the previously existing problems. Their implementation saves the new GDT content and then forwards the call to the host when appropriate, i.e. immediately when the target process is running or on context switch otherwise (i.e. on fork and on ptrace() calls). In SKAS mode, we must switch registers on each context switch (because SKAS does not switches tls_array together with current->mm). Also, added get_cpu() locking; this has been done for SKAS mode, since TT does not need it (it does not use smp_processor_id()). Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: clean arch_switch usagePaolo 'Blaisorblade' Giarrusso2006-03-316-6/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Call arch_switch also in switch_to_skas, even if it's, for now, a no-op for that case (and mark this in the comment); this will change soon. Also, arch_switch for TT mode is actually useless when the PT proxy (a complicate debugging instrumentation for TT mode) is not enabled. In fact, it only calls update_debugregs, which checks debugregs_seq against seq (to check if the registers are up-to-date - seq here means a "version number" of the registers). If the ptrace proxy is not enabled, debugregs_seq always stays 0 and update_debugregs will be a no-op. So, optimize this out (the compiler can't do it). Also, I've been disappointed by the fact that it would make a lot of sense if, after calling a successful update_debugregs(current->thread.arch.debugregs_seq), current->thread.arch.debugregs_seq were updated with the new debugregs_seq. But this is not done. Is this a bug or a feature? For all purposes, it seems a bug (otherwise the whole mechanism does not make sense, which is also a possibility to check), which causes some performance only problems (not correctness), since we write_debugregs when not needed. Also, as suggested by Jeff, remove a redundant enabling of SIGVTALRM, comprised in the subsequent local_irq_enable(). I'm just a bit dubious if ordering matters there... Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: split ldt.h in arch-independent and arch-dependant codePaolo 'Blaisorblade' Giarrusso2006-03-311-1/+1
| | | | | | | | | | | | | | | | | | | | ldt-{i386,x86_64}.h is made of two different parts - some code for parsing of LDT descriptors, which is arch-dependant, and the code to handle uml_ldt_t (an LDT block inside UML), which is mostly arch-independant (among x86 and x86_64, at least). Join the common part in a single file (ldt.h) and split the rest away (host_ldt-{i386,x86_64}.h). This is needed because processor.h, with next patches, will start including the LDT descriptor parsing macros in host_ldt.h, but it can't include ldt.h because it uses semaphores (and to define semaphores one must first include processor.h!). Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: idle thread needn't take access to init_mmPaolo 'Blaisorblade' Giarrusso2006-03-311-4/+0
| | | | | | | | | | | | | | | Comparing this code which is the actual body of the arch-independent cpu_idle(), it is clear that it's unnecessary to set ->mm and ->active_mm; beyond that, a kernel thread is not supposed to have ->mm != NULL, only active_mm. This showed up because I used the assumption (which is IMHO valid) that kernel thread have their ->mm == NULL, and it failed for this thread. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: fix min usageAl Viro2006-03-311-1/+1
| | | | | | | | | | type-safe min() in arch/um/drivers/mconsole_kern.c Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: remove unused make variablesAl Viro2006-03-311-3/+0
| | | | | | | | | | Removed assignments to unused variables in arch/um/os-Linux/Makefile Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: sparse cleanupsAl Viro2006-03-3113-90/+83
| | | | | | | | | | misc sparse annotations Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: kconfigsAl Viro2006-03-311-0/+3
| | | | | | | | | | kconfig sanitized around drivers/net Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: eliminate duplicate mrpropered filesAl Viro2006-03-311-2/+1
| | | | | | | | | | no need to add the same file twice to MRPROPER_FILES Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: clean up remapping code build magicAl Viro2006-03-314-27/+7
| | | | | | | | | | kills unmap magic Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: eliminate symlinks to host archAl Viro2006-03-314-54/+19
| | | | | | | | | | kills symlinks in arch/um/sys-* Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: fix initcall return valuesJeff Dike2006-03-318-85/+8
| | | | | | | | | | A number of UML initcalls were improperly returning 1. Also removed any nearby emacs formatting comments. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: redeclare highmemJeff Dike2006-03-312-2/+2
| | | | | | | | | | The earlier printf patch missed a corresponding change in the printed variable. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] UML: Hotplug memory, take 2Jeff Dike2006-03-316-47/+185
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Changes since first version added check for MADV_REMOVE support on the host fixed error return botch shrunk sprintf array by one character This adds hotplug memory support to UML. The mconsole syntax is config mem=[+-]n[KMG] In other words, add or subtract some number of kilobytes, megabytes, or gigabytes. Unplugged pages are allocated and then madvise(MADV_TRUNCATE), which is a currently experimental madvise extension. These pages are tracked so they can be plugged back in later if the admin decides to give them back. The first page to be unplugged is used to keep track of about 4M of other pages. A list_head is the first thing on this page. The rest is filled with addresses of other unplugged pages. This first page is not madvised, obviously. When this page is filled, the next page is used in a similar way and linked onto a list with the first page. Etc. This whole process reverses when pages are plugged back in. When a tracking page no longer tracks any unplugged pages, then it is next in line for plugging, which is done by freeing pages back to the kernel. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] pidhash: don't count idle threadsOleg Nesterov2006-03-291-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | fork_idle() does unhash_process() just after copy_process(). Contrary, boot_cpu's idle thread explicitely registers itself for each pid_type with nr = 0. copy_process() already checks p->pid != 0 before process_counts++, I think we can just skip attach_pid() calls and job control inits for idle threads and kill unhash_process(). We don't need to cleanup ->proc_dentry in fork_idle() because with this patch idle threads are never hashed in kernel/pid.c:pid_hash[]. We don't need to hash pid == 0 in pidmap_init(). free_pidmap() is never called with pid == 0 arg, so it will never be reused. So it is still possible to use pid == 0 in any PIDTYPE_xxx namespace from kernel/pid.c's POV. However with this patch we don't hash pid == 0 for PIDTYPE_PID case. We still have have PIDTYPE_PGID/PIDTYPE_SID entries with pid == 0: /sbin/init and kernel threads which don't call daemonize(). Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Notifier chain update: API changesAlan Stern2006-03-272-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kernel's implementation of notifier chains is unsafe. There is no protection against entries being added to or removed from a chain while the chain is in use. The issues were discussed in this thread: http://marc.theaimsgroup.com/?l=linux-kernel&m=113018709002036&w=2 We noticed that notifier chains in the kernel fall into two basic usage classes: "Blocking" chains are always called from a process context and the callout routines are allowed to sleep; "Atomic" chains can be called from an atomic context and the callout routines are not allowed to sleep. We decided to codify this distinction and make it part of the API. Therefore this set of patches introduces three new, parallel APIs: one for blocking notifiers, one for atomic notifiers, and one for "raw" notifiers (which is really just the old API under a new name). New kinds of data structures are used for the heads of the chains, and new routines are defined for registration, unregistration, and calling a chain. The three APIs are explained in include/linux/notifier.h and their implementation is in kernel/sys.c. With atomic and blocking chains, the implementation guarantees that the chain links will not be corrupted and that chain callers will not get messed up by entries being added or removed. For raw chains the implementation provides no guarantees at all; users of this API must provide their own protections. (The idea was that situations may come up where the assumptions of the atomic and blocking APIs are not appropriate, so it should be possible for users to handle these things in their own way.) There are some limitations, which should not be too hard to live with. For atomic/blocking chains, registration and unregistration must always be done in a process context since the chain is protected by a mutex/rwsem. Also, a callout routine for a non-raw chain must not try to register or unregister entries on its own chain. (This did happen in a couple of places and the code had to be changed to avoid it.) Since atomic chains may be called from within an NMI handler, they cannot use spinlocks for synchronization. Instead we use RCU. The overhead falls almost entirely in the unregister routine, which is okay since unregistration is much less frequent that calling a chain. Here is the list of chains that we adjusted and their classifications. None of them use the raw API, so for the moment it is only a placeholder. ATOMIC CHAINS ------------- arch/i386/kernel/traps.c: i386die_chain arch/ia64/kernel/traps.c: ia64die_chain arch/powerpc/kernel/traps.c: powerpc_die_chain arch/sparc64/kernel/traps.c: sparc64die_chain arch/x86_64/kernel/traps.c: die_chain drivers/char/ipmi/ipmi_si_intf.c: xaction_notifier_list kernel/panic.c: panic_notifier_list kernel/profile.c: task_free_notifier net/bluetooth/hci_core.c: hci_notifier net/ipv4/netfilter/ip_conntrack_core.c: ip_conntrack_chain net/ipv4/netfilter/ip_conntrack_core.c: ip_conntrack_expect_chain net/ipv6/addrconf.c: inet6addr_chain net/netfilter/nf_conntrack_core.c: nf_conntrack_chain net/netfilter/nf_conntrack_core.c: nf_conntrack_expect_chain net/netlink/af_netlink.c: netlink_chain BLOCKING CHAINS --------------- arch/powerpc/platforms/pseries/reconfig.c: pSeries_reconfig_chain arch/s390/kernel/process.c: idle_chain arch/x86_64/kernel/process.c idle_notifier drivers/base/memory.c: memory_chain drivers/cpufreq/cpufreq.c cpufreq_policy_notifier_list drivers/cpufreq/cpufreq.c cpufreq_transition_notifier_list drivers/macintosh/adb.c: adb_client_list drivers/macintosh/via-pmu.c sleep_notifier_list drivers/macintosh/via-pmu68k.c sleep_notifier_list drivers/macintosh/windfarm_core.c wf_client_list drivers/usb/core/notify.c usb_notifier_list drivers/video/fbmem.c fb_notifier_list kernel/cpu.c cpu_chain kernel/module.c module_notify_list kernel/profile.c munmap_notifier kernel/profile.c task_exit_notifier kernel/sys.c reboot_notifier_list net/core/dev.c netdev_chain net/decnet/dn_dev.c: dnaddr_chain net/ipv4/devinet.c: inetaddr_chain It's possible that some of these classifications are wrong. If they are, please let us know or submit a patch to fix them. Note that any chain that gets called very frequently should be atomic, because the rwsem read-locking used for blocking chains is very likely to incur cache misses on SMP systems. (However, if the chain's callout routines may sleep then the chain cannot be atomic.) The patch set was written by Alan Stern and Chandra Seetharaman, incorporating material written by Keith Owens and suggestions from Paul McKenney and Andrew Morton. [jes@sgi.com: restructure the notifier chain initialization macros] Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Jes Sorensen <jes@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] unify PFN_* macrosDave Hansen2006-03-271-2/+1
| | | | | | | | | | | | | | | | | | | | Just about every architecture defines some macros to do operations on pfns. They're all virtually identical. This patch consolidates all of them. One minor glitch is that at least i386 uses them in a very skeletal header file. To keep away from #include dependency hell, I stuck the new definitions in a new, isolated header. Of all of the implementations, sh64 is the only one that varied by a bit. It used some masks to ensure that any sign-extension got ripped away before the arithmetic is done. This has been posted to that sh64 maintainers and the development list. Compiles on x86, x86_64, ia64 and ppc64. Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: fix thread startup raceJeff Dike2006-03-271-28/+27
| | | | | | | | | | | | | | | This fixes a race in the starting of write_sigio_thread. Previously, some of the data needed by the thread was initialized after the clone. If the thread ran immediately, it would see the uninitialized data, including an empty pollfds, which would cause it to hang. We move the data initialization to before the clone, and adjust the error paths and cleanup accordingly. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: prevent umid theftJeff Dike2006-03-271-10/+23
| | | | | | | | | | | Behavior when booting two UMLs with the same umid was broken. The second one would steal the umid. This fixes that, making the second UML take a random umid instead. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: fix segfault on signal deliveryJeff Dike2006-03-272-30/+85
| | | | | | | | | | | | | | | | | | | This fixes a process segfault where a signal was being delivered such that a new stack page needed to be allocated to hold the signal frame. This was tripping some logic in the page fault handler which wouldn't allocate the page if the faulting address was more that 32 bytes lower than the current stack pointer. Since a signal frame is greater than 32 bytes, this exercised that case. It's fixed by updating the SP in the pt_regs before starting to copy the signal frame. Since those are the registers that will be copied on to the stack, we have to be careful to put the original SP, not the new one which points to the signal frame, on the stack. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: allow ubd devices to be shared in a clusterJeff Dike2006-03-271-33/+43
| | | | | | | | | | | This adds a 'c' option to the ubd switch which turns off host file locking so that the device can be shared, as with a cluster. There's also some whitespace cleanup while I was in this file. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: oS header cleanupsJeff Dike2006-03-273-2/+14
| | | | | | | | | This rearranges the OS declarations by moving some declarations into os.h. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: move tty logging to os-LinuxJeff Dike2006-03-274-24/+9
| | | | | | | | | | | The serial UML OS-abstraction layer patch (um/kernel dir). This moves all systemcalls from tty_log.c file under os-Linux dir Signed-off-by: Gennady Sharapov <Gennady.V.Sharapov@intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: more carefully test whether we are in a system callBodo Stroesser2006-03-272-4/+33
| | | | | | | | | | | | | | | | | | | | For security reasons, UML in is_syscall() needs to have access to code in vsyscall-page. The current implementation grants this access by explicitly allowing access to vsyscall in access_ok_skas(). With this change, copy_from_user() may be used to read the code. Ptrace access to vsyscall-page for debugging already was implemented in get_user_pages() by mainline. In i386, copy_from_user can't access vsyscall-page, but returns EFAULT. To make UML behave as i386 does, I changed is_syscall to use access_process_vm(current) to read the code from vsyscall-page. This doesn't hurt security, but simplifies the code and prepares implementation of stub-vmas. Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: move sigio_user.c to os-Linux/sigio.cJeff Dike2006-03-276-16/+19
| | | | | | | | | | | | The serial UML OS-abstraction layer patch (um/kernel dir). This moves sigio_user.c to os-Linux dir Signed-off-by: Gennady Sharapov <Gennady.V.Sharapov@intel.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: move SIGIO startup code to os-Linux/start_up.cJeff Dike2006-03-276-157/+148
| | | | | | | | | | | | The serial UML OS-abstraction layer patch (um/kernel dir). This moves all startup code from sigio_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 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: merge irq_user.c and irq.cJeff Dike2006-03-273-325/+295
| | | | | | | | | | | | The serial UML OS-abstraction layer patch (um/kernel dir). This joins irq_user.c and irq.c files. Signed-off-by: Gennady Sharapov <Gennady.V.Sharapov@intel.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: move libc-dependent irq code to os-LinuxJeff Dike2006-03-2710-161/+288
| | | | | | | | | | | | The serial UML OS-abstraction layer patch (um/kernel dir). This moves all systemcalls from irq_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 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: fix some printf formatsJeff Dike2006-03-271-3/+3
| | | | | | | | | Some printf formats are incorrect for large memory sizes. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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