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* um: unify ptrace_user.hAl Viro2011-11-022-7/+5
| | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
* um: merge os-Linux/tls.c into arch/x86/um/os-Linux/tls.cAl Viro2011-11-022-37/+2
| | | | | | | | | it's i386-specific; moreover, analogs on other targets have incompatible interface - PTRACE_GET_THREAD_AREA does exist elsewhere, but struct user_desc does *not* Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
* um: take chan_*.h and line.h to arch/um/driversAl Viro2011-11-021-1/+1
| | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
* um: take register_winch_irq() into the caller of is_skas_winch()Al Viro2011-11-021-5/+1
| | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
* um: take arch/um/sys-x86 to arch/x86/umAl Viro2011-11-027-353/+1
| | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
* um: sysdep/barrier.h is not used for anythingAl Viro2011-11-021-1/+0
| | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
* um: shared/process.h is empty now; kill itAl Viro2011-11-025-5/+0
| | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
* um: finish conversion to mcontext_tAl Viro2011-11-023-4/+35
| | | | | | | | now we don't mix host and guest signal frame layouts anymore; moreover, we don't need host's struct sigcontext at all. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
* um: start switching the references to host mcontext_t to its userland typeAl Viro2011-11-023-20/+18
| | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
* um: take userland definition of barrier() to user.hAl Viro2011-11-021-3/+0
| | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
* um: fill the handlers array at build timeAl Viro2011-11-023-11/+20
| | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
* um: simplify set_handler()Al Viro2011-11-023-26/+18
| | | | | | | | | | For one thing, we always block the same signals (IRQ ones - IO, WINCH, VTALRM), so there's no need to pass sa_mask elements in arguments. For another, the flags depend only on whether it's an IRQ signal or not (we add SA_RESTART for them). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
* um: don't bother blocking SIGARLM and SIGUSR1Al Viro2011-11-023-9/+8
| | | | | | | | We used to generate those, but we hadn't done that for a long time. No need to bother blocking them for signal handlers. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
* um: switch stub_segv_handler to SA_SIGINFO variant, get rid of magic crap in ↵Al Viro2011-11-021-2/+2
| | | | | | | there Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
* um: merge arch/um/os-Linux/sys-{i386,x86_64}Al Viro2011-11-029-85/+57
| | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
* um: merge hard_handler() instances, switch to use of SA_SIGINFOAl Viro2011-11-025-35/+10
| | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
* um: kill dead code around uaccessAl Viro2011-11-022-34/+2
| | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
* um: -include user.h for USER_OBJ, trim includesAl Viro2011-11-0223-40/+0
| | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
* um: Save FPU registers between task switchesIngo van Lil2011-09-143-3/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Some time ago Jeff prepared 42daba316557 ("uml: stop saving process FP state") for UML to stop saving the process FP state between task switches. The assumption was that since with SKAS0 every guest process runs inside a host process context the host OS will take care of keeping the proper FP state. Unfortunately this is not true for multi-threaded applications, where all guest threads share a single host process context yet all may use the FPU on their own. Although I haven't verified it I suspect things to be even worse in SKAS3 mode where all guest processes run inside a single host process. The patch reintroduces the saving and restoring of the FP context between task switches. [richard@nod.at: Ingo posted this patch in 2009, sadly it was never applied and got lost. Now in 2011 the problem was reported by Gunnar.] Signed-off-by: Ingo van Lil <inguin@gmx.de> Signed-off-by: Richard Weinberger <richard@nod.at> Reported-by: <gunnarlindroth@hotmail.com> Tested-by: <gunnarlindroth@hotmail.com> Cc: Stanislav Meduna <stano@meduna.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* um: disable scan_elf_aux() on x86_64Richard Weinberger2011-07-253-7/+8
| | | | | | | | Reusing the host's vDSO makes only sense on x86_32. Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: free resourcesDavidlohr Bueso2011-07-251-2/+4
| | | | | | | | | | | When creating the temp file there's a memory and file descriptor leak upon error. Signed-off-by: Davidlohr Bueso <dave@gnu.org> Signed-off-by: Richard Weinberger <richard@nod.at> Reviewed-by: Vitaliy Ivanov <vitalivanov@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: helper.c warning correctionsVitaliy Ivanov2011-07-251-2/+2
| | | | | | | | | | | | | Fix this warning: arch/um/os-Linux/helper.c: In function `helper_child': arch/um/os-Linux/helper.c:38:7: warning: ignoring return value of `write', declared with attribute warn_unused_result [richard@nod.at: happens only with -D_FORTIFY_SOURCE=2] Signed-off-by: Vitaliy Ivanov <vitalivanov@gmail.com> Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* um: fix _FORTIFY_SOURCE=2 support for kernel modulesRichard Weinberger2011-07-251-0/+5
| | | | | | | | | | | | | | When UML is compiled with _FORTIFY_SOURCE we have to export all _chk() functions which are used in modules. For now it's only the case for __sprintf_chk(). Tested-by: Florian Fainelli <florian@openwrt.org> Reported-by: Florian Fainelli <florian@openwrt.org> Signed-off-by: Richard Weinberger <richard@nod.at> Acked-by: Vitaliy Ivanov <vitalivanov@gmail.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* um: fix crash while os_dump_core()Richard Weinberger2011-05-251-0/+1
| | | | | | | | | | os_dump_core() emits SIGTERM to terminate all UML processes. Kernel threads have to exit on SIGTERM instead of calling last_ditch_exit(). Multiple calls to last_ditch_exit() can cause a crash. Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* um: add earlyprintk supportRichard Weinberger2011-05-251-0/+5
| | | | | | | | | User Mode Linux can also benefit from earlyprintk. UML's earlyprintk writes kernel messages directly to stdout. Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* um: remove SIGHUP handlerRichard Weinberger2011-05-251-1/+0
| | | | | | | | The UML kernel ignores SIGHUP anyway. This handler is in vain. Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* um: fix UML_LIB_PATHRichard Weinberger2011-05-251-1/+1
| | | | | | | | | UML_LIB_PATH is hardcoded to /usr/lib/uml/, on 64bit systems UML_LIB_PATH needs to be /usr/lib64/uml/. Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* um: fix abortRichard Weinberger2011-05-181-1/+22
| | | | | | | | | | | | | | | | os_dump_core() uses abort() to terminate UML in case of an fatal error. glibc's abort() calls raise(SIGABRT) which makes use of tgkill(). tgkill() has no effect within UML's kernel threads because they are not pthreads. As fallback abort() executes an invalid instruction to terminate the process. Therefore UML gets killed by SIGSEGV and leaves a ugly log entry in the host's kernel ring buffer. To get rid of this we use our own abort routine. Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* um: fix global timer issue when using CONFIG_NO_HZRichard Weinberger2010-10-261-1/+1
| | | | | | | | | | | | | | | This fixes a issue which was introduced by fe2cc53e ("uml: track and make up lost ticks"). timeval_to_ns() returns long long and not int. Due to that UML's timer did not work properlt and caused timer freezes. Signed-off-by: Richard Weinberger <richard@nod.at> Acked-by: Pekka Enberg <penberg@kernel.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Deal with missing exports for hostfsAl Viro2010-08-092-0/+19
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* um: os-linux/mem.c needs sys/stat.hLiu Aleaxander2010-06-291-0/+1
| | | | | | | | | | | | The os-linux/mem.c file calls fchmod function, which is declared in sys/stat.h header file, so include it. Fixes build breakage under FC13. Signed-off-by: Liu Aleaxander <Aleaxander@gmail.com> Acked-by: Boaz Harrosh <bharrosh@panasas.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: Fix build breakage after slab.h changesJan Kiszka2010-04-191-1/+0
| | | | | | | | | We now have to to include linux/slab.h explicitly for kmalloc & friends. Files that build against host headers already get their prototypes via um_malloc.h, linux/slab.h may even be unavailable. Signed-off-by: Jan Kiszka <jan.kiszka@web.de> Signed-off-by: Tejun Heo <tj@kernel.org>
* include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-301-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
* includecheck fix: um, helper.cJaswinder Singh Rajput2009-09-201-1/+0
| | | | | | | | | | | | fix the following 'make includecheck' warning: arch/um/os-Linux/helper.c: linux/limits.h is included more than once. Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com> Cc: jdike@addtoit.com Cc: Sam Ravnborg <sam@ravnborg.org> LKML-Reference: <1247064950.4382.45.camel@ht.satnam> Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
* uml: improve error messagesWANG Cong2009-04-011-4/+4
| | | | | | | | | These error messages are from check_sysemu(), not check_ptrace(). Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: fix WARNING: vmlinux: 'memcpy' exported twiceakpm@linux-foundation.org2009-03-121-1/+4
| | | | | | | | | | | | | | | | | Fix the following warning on x86_64: LD vmlinux.o MODPOST vmlinux.o WARNING: vmlinux: 'memcpy' exported twice. Previous export was in vmlinux For x86_64, this symbol is already exported from arch/um/sys-x86_64/ksyms.c. Reported-by: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com> Tested-by: Boaz Harrosh <bharrosh@panasas.com> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* um: Kill directly reference of netdev->privWang Chen2008-12-042-2/+2
| | | | | | | Simply replace netdev->priv with netdev_priv(). Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* x86, um: get rid of arch/um/os symlinkAl Viro2008-10-221-11/+0
| | | | | | | | we can get DEV_NULL defined for arch/um/drivers/null.c in less convoluted ways, TYVM... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* x86, um: get rid of excessive includes of uml-config.hAl Viro2008-10-221-1/+0
| | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* uml: remove the dead TTY_LOG codeAdrian Bunk2008-10-162-220/+0
| | | | | | | | | | Remove the dead CONFIG_TTY_LOG (no kconfig option). Reported-by: Robert P. J. Day <rpjday@crashcourse.ca> Signed-off-by: Adrian Bunk <bunk@kernel.org> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* UML: make several more things staticWANG Cong2008-07-244-4/+4
| | | | | | | | | | | | | | - Make some variables and functions static, since they don't need to be global. - Remove an unused function - arch/um/kernel/time.c::sched_clock(). - Clean the style a bit as complained by checkpatch.pl. Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: WANG Cong <wangcong@zeuux.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: work around broken host PTRACE_SYSEMUJeff Dike2008-06-121-9/+16
| | | | | | | | | | Fedora broke PTRACE_SYSEMU again, and UML crashes as a result when it doesn't need to. This patch makes the PTRACE_SYSEMU check fail gracefully and makes UML fall back to PTRACE_SYSCALL. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: remove include of asm/user.hJeff Dike2008-06-121-2/+2
| | | | | | | | | I allowed an include of asm/user.h to sneak back in. This patch replaces it with sys/user.h. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: PATH_MAX needs limits.hIngo Molnar2008-06-061-0/+1
| | | | | | | | | Include limits.h to get a definition of PATH_MAX. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: stub needs to tolerate SIGWINCHJeff Dike2008-06-061-1/+1
| | | | | | | | | | We lost the marking of SIGWINCH as being OK to receive during stub execution, causing a panic should that happen. Cc: Benedict Verheyen <benedict.verheyen@gmail.com> Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: deal with inaccessible address space startTom Spink2008-06-062-9/+24
| | | | | | | | | | | | | | | | | | | | | This patch makes os_get_task_size locate the bottom of the address space, as well as the top. This is for systems which put a lower limit on mmap addresses. It works by manually scanning pages from zero onwards until a valid page is found. Because the bottom of the address space may not be zero, it's not sufficient to assume the top of the address space is the size of the address space. The size is the difference between the top address and bottom address. [jdike@addtoit.com: changed the name to reflect that this function is supposed to return the top of the process address space, not its size and changed the return value to reflect that. Also some minor formatting changes] Signed-off-by: Tom Spink <tspink@gmail.com> Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: deal with host time going backwardsJeff Dike2008-06-061-0/+7
| | | | | | | | | | | | Protection against the host's time going backwards (eg, ntp activity on the host) by keeping track of the time at the last tick and if it's greater than the current time, keep time stopped until the host catches up. Cc: Nix <nix@esperi.org.uk> Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fix include order in sys-i386/registers.cAl Viro2008-05-211-0/+1
| | | | | | | | | We want sys/ptrace.h before any includes of linux/ptrace.h and asm/user.h pulls the latter. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: track and make up lost ticksJeff Dike2008-05-132-4/+51
| | | | | | | | | | | | Alarm delivery could be noticably late in the !CONFIG_NOHZ case because lost ticks weren't being taken into account. This is now treated more carefully, with the time between ticks being calculated and the appropriate number of ticks delivered to the timekeeping system. Cc: Nix <nix@esperi.org.uk> Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: random driver fixesJeff Dike2008-05-131-14/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The random driver would essentially hang if the host's /dev/random returned -EAGAIN. There was a test of need_resched followed by a schedule inside the loop, but that didn't help and it's the wrong way to work anyway. The right way is to ask for an interrupt when there is input available from the host and handle it then rather than polling. Now, when the host's /dev/random returns -EAGAIN, the driver asks for a wakeup when there's randomness available again and sleeps. The interrupt routine just wakes up whatever processes are sleeping on host_read_wait. There is an atomic_t, host_sleep_count, which counts the number of processes waiting for randomness. When this reaches zero, the interrupt is disabled. An added complication is that async I/O notification was only recently added to /dev/random (by me), so essentially all hosts will lack it. So, we use the sigio workaround here, which is to have a separate thread poll on the descriptor and send an interrupt when there is input on it. This mechanism is activated when a process gets -EAGAIN (activating this multiple times is harmless, if a bit wasteful) and deactivated by the last process still waiting. The module name was changed from "random" to "hw_random" in order for udev to recognize it. The sigio workaround needed some changes. sigio_broken was added for cases when we know that async notification doesn't work. This is now called from maybe_sigio_broken, which deals with pts devices. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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