- 14 12月, 2014 1 次提交
-
-
由 David Drysdale 提交于
Hook up x86-64, i386 and x32 ABIs. Signed-off-by: NDavid Drysdale <drysdale@google.com> Cc: Meredydd Luff <meredydd@senatehouse.org> Cc: Shuah Khan <shuah.kh@samsung.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Rich Felker <dalias@aerifal.cx> Cc: Christoph Hellwig <hch@infradead.org> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
- 01 11月, 2014 1 次提交
-
-
由 Andy Lutomirski 提交于
Rusty noticed a Really Bad Bug (tm) in my NT fix. The entry code reads out of bounds, causing the NT fix to be unreliable. But, and this is much, much worse, if your stack is somehow just below the top of the direct map (or a hole), you read out of bounds and crash. Excerpt from the crash: [ 1.129513] RSP: 0018:ffff88001da4bf88 EFLAGS: 00010296 2b:* f7 84 24 90 00 00 00 testl $0x4000,0x90(%rsp) That read is deterministically above the top of the stack. I thought I even single-stepped through this code when I wrote it to check the offset, but I clearly screwed it up. Fixes: 8c7aa698 ("x86_64, entry: Filter RFLAGS.NT on entry from userspace") Reported-by: NRusty Russell <rusty@ozlabs.org> Cc: stable@vger.kernel.org Signed-off-by: NAndy Lutomirski <luto@amacapital.net> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
- 07 10月, 2014 1 次提交
-
-
由 Andy Lutomirski 提交于
The NT flag doesn't do anything in long mode other than causing IRET to #GP. Oddly, CPL3 code can still set NT using popf. Entry via hardware or software interrupt clears NT automatically, so the only relevant entries are fast syscalls. If user code causes kernel code to run with NT set, then there's at least some (small) chance that it could cause trouble. For example, user code could cause a call to EFI code with NT set, and who knows what would happen? Apparently some games on Wine sometimes do this (!), and, if an IRET return happens, they will segfault. That segfault cannot be handled, because signal delivery fails, too. This patch programs the CPU to clear NT on entry via SYSCALL (both 32-bit and 64-bit, by my reading of the AMD APM), and it clears NT in software on entry via SYSENTER. To save a few cycles, this borrows a trick from Jan Beulich in Xen: it checks whether NT is set before trying to clear it. As a result, it seems to have very little effect on SYSENTER performance on my machine. There's another minor bug fix in here: it looks like the CFI annotations were wrong if CONFIG_AUDITSYSCALL=n. Testers beware: on Xen, SYSENTER with NT set turns into a GPF. I haven't touched anything on 32-bit kernels. The syscall mask change comes from a variant of this patch by Anish Bhatt. Note to stable maintainers: there is no known security issue here. A misguided program can set NT and cause the kernel to try and fail to deliver SIGSEGV, crashing the program. This patch fixes Far Cry on Wine: https://bugs.winehq.org/show_bug.cgi?id=33275 Cc: <stable@vger.kernel.org> Reported-by: NAnish Bhatt <anish@chelsio.com> Signed-off-by: NAndy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/395749a5d39a29bd3e4b35899cf3a3c1340e5595.1412189265.git.luto@amacapital.netSigned-off-by: NH. Peter Anvin <hpa@zytor.com>
-
- 24 9月, 2014 1 次提交
-
-
由 Richard Guy Briggs 提交于
Since the arch is found locally in __audit_syscall_entry(), there is no need to pass it in as a parameter. Delete it from the parameter list. x86* was the only arch to call __audit_syscall_entry() directly and did so from assembly code. Signed-off-by: NRichard Guy Briggs <rgb@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: x86@kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-audit@redhat.com Signed-off-by: NEric Paris <eparis@redhat.com> --- As this patch relies on changes in the audit tree, I think it appropriate to send it through my tree rather than the x86 tree.
-
- 23 7月, 2013 1 次提交
-
-
由 Ramkumar Ramachandra 提交于
Commit 3fe26fa3 ("x86: get rid of pt_regs argument in sigreturn variants", from 2012-11-12) changed the body of PTREGSCALL to drop arg, and updated the callsites; unfortunately, it forgot to update the macro argument list, leaving an unused argument. Fix this. Signed-off-by: NRamkumar Ramachandra <artagnon@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Link: http://lkml.kernel.org/r/1373479468-7175-1-git-send-email-artagnon@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
- 08 2月, 2013 1 次提交
-
-
由 Jan Beulich 提交于
For some reason they didn't get replaced so far by their paravirt equivalents, resulting in code to be run with interrupts disabled that doesn't expect so (causing, in the observed case, a BUG_ON() to trigger) when syscall auditing is enabled. David (Cc-ed) came up with an identical fix, so likely this can be taken to count as an ack from him. Reported-by: NPeter Moody <pmoody@google.com> Signed-off-by: NJan Beulich <jbeulich@suse.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Link: http://lkml.kernel.org/r/5108E01902000078000BA9C5@nat28.tlf.novell.comSigned-off-by: NIngo Molnar <mingo@kernel.org> Cc: stable@vger.kernel.org Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: David Vrabel <david.vrabel@citrix.com> Tested-by: NPeter Moody <pmoody@google.com>
-
- 04 2月, 2013 2 次提交
-
-
由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
-
由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
-
- 31 1月, 2013 1 次提交
-
-
由 Jan Beulich 提交于
For some reason they didn't get replaced so far by their paravirt equivalents, resulting in code to be run with interrupts disabled that doesn't expect so (causing, in the observed case, a BUG_ON() to trigger) when syscall auditing is enabled. David (Cc-ed) came up with an identical fix, so likely this can be taken to count as an ack from him. Reported-by: NPeter Moody <pmoody@google.com> Signed-off-by: NJan Beulich <jbeulich@suse.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Link: http://lkml.kernel.org/r/5108E01902000078000BA9C5@nat28.tlf.novell.comSigned-off-by: NIngo Molnar <mingo@kernel.org> Cc: stable@vger.kernel.org Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: David Vrabel <david.vrabel@citrix.com> Tested-by: NPeter Moody <pmoody@google.com>
-
- 20 12月, 2012 1 次提交
-
-
由 Al Viro 提交于
Again, conditional on CONFIG_GENERIC_SIGALTSTACK Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
-
- 29 11月, 2012 1 次提交
-
-
由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
-
- 01 10月, 2012 1 次提交
-
-
由 Al Viro 提交于
32bit wrapper is lost on that; 64bit one is *not*, since we need to arrange for full pt_regs on stack when we call sys_execve() and we need to load callee-saved ones from there afterwards. Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
-
- 22 9月, 2012 1 次提交
-
-
由 H. Peter Anvin 提交于
When Supervisor Mode Access Prevention (SMAP) is enabled, access to userspace from the kernel is controlled by the AC flag. To make the performance of manipulating that flag acceptable, there are two new instructions, STAC and CLAC, to set and clear it. This patch adds those instructions, via alternative(), when the SMAP feature is enabled. It also adds X86_EFLAGS_AC unconditionally to the SYSCALL entry mask; there is simply no reason to make that one conditional. Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com> Link: http://lkml.kernel.org/r/1348256595-29119-9-git-send-email-hpa@linux.intel.com
-
- 21 4月, 2012 2 次提交
-
-
由 H. Peter Anvin 提交于
Remove open-coded exception table entries in arch/x86/ia32/ia32entry.S, and replace them with _ASM_EXTABLE() macros; this will allow us to change the format and type of the exception table entries. This one was missed from the previous patch to this file. Signed-off-by: NH. Peter Anvin <hpa@zytor.com> Cc: David Daney <david.daney@cavium.com> Link: http://lkml.kernel.org/r/CA%2B55aFyijf43qSu3N9nWHEBwaGbb7T2Oq9A=9EyR=Jtyqfq_cQ@mail.gmail.com
-
由 H. Peter Anvin 提交于
Remove open-coded exception table entries in arch/x86/ia32/ia32entry.S, and replace them with _ASM_EXTABLE() macros; this will allow us to change the format and type of the exception table entries. Signed-off-by: NH. Peter Anvin <hpa@zytor.com> Cc: David Daney <david.daney@cavium.com> Link: http://lkml.kernel.org/r/CA%2B55aFyijf43qSu3N9nWHEBwaGbb7T2Oq9A=9EyR=Jtyqfq_cQ@mail.gmail.com
-
- 18 1月, 2012 3 次提交
-
-
由 Eric Paris 提交于
Every arch calls: if (unlikely(current->audit_context)) audit_syscall_entry() which requires knowledge about audit (the existance of audit_context) in the arch code. Just do it all in static inline in audit.h so that arch's can remain blissfully ignorant. Signed-off-by: NEric Paris <eparis@redhat.com>
-
由 Eric Paris 提交于
In the ia32entry syscall exit audit fastpath we have assembly code which calls __audit_syscall_exit directly. This code was, however, zeroes the upper 32 bits of the return code. It then proceeded to call code which expects longs to be 64bits long. In order to handle code which expects longs to be 64bit we sign extend the return code if that code is an error. Thus the __audit_syscall_exit function can correctly handle using the values in snprintf("%ld"). This fixes the regression introduced in 5cbf1565. Old record: type=SYSCALL msg=audit(1306197182.256:281): arch=40000003 syscall=192 success=no exit=4294967283 New record: type=SYSCALL msg=audit(1306197182.256:281): arch=40000003 syscall=192 success=no exit=-13 Signed-off-by: NEric Paris <eparis@redhat.com> Acked-by: NH. Peter Anvin <hpa@zytor.com>
-
由 Eric Paris 提交于
The audit system previously expected arches calling to audit_syscall_exit to supply as arguments if the syscall was a success and what the return code was. Audit also provides a helper AUDITSC_RESULT which was supposed to simplify things by converting from negative retcodes to an audit internal magic value stating success or failure. This helper was wrong and could indicate that a valid pointer returned to userspace was a failed syscall. The fix is to fix the layering foolishness. We now pass audit_syscall_exit a struct pt_reg and it in turns calls back into arch code to collect the return value and to determine if the syscall was a success or failure. We also define a generic is_syscall_success() macro which determines success/failure based on if the value is < -MAX_ERRNO. This works for arches like x86 which do not use a separate mechanism to indicate syscall failure. We make both the is_syscall_success() and regs_return_value() static inlines instead of macros. The reason is because the audit function must take a void* for the regs. (uml calls theirs struct uml_pt_regs instead of just struct pt_regs so audit_syscall_exit can't take a struct pt_regs). Since the audit function takes a void* we need to use static inlines to cast it back to the arch correct structure to dereference it. The other major change is that on some arches, like ia64, MIPS and ppc, we change regs_return_value() to give us the negative value on syscall failure. THE only other user of this macro, kretprobe_example.c, won't notice and it makes the value signed consistently for the audit functions across all archs. In arch/sh/kernel/ptrace_64.c I see that we were using regs[9] in the old audit code as the return value. But the ptrace_64.h code defined the macro regs_return_value() as regs[3]. I have no idea which one is correct, but this patch now uses the regs_return_value() function, so it now uses regs[3]. For powerpc we previously used regs->result but now use the regs_return_value() function which uses regs->gprs[3]. regs->gprs[3] is always positive so the regs_return_value(), much like ia64 makes it negative before calling the audit code when appropriate. Signed-off-by: NEric Paris <eparis@redhat.com> Acked-by: H. Peter Anvin <hpa@zytor.com> [for x86 portion] Acked-by: Tony Luck <tony.luck@intel.com> [for ia64] Acked-by: Richard Weinberger <richard@nod.at> [for uml] Acked-by: David S. Miller <davem@davemloft.net> [for sparc] Acked-by: Ralf Baechle <ralf@linux-mips.org> [for mips] Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [for ppc]
-
- 06 12月, 2011 2 次提交
-
-
由 Jan Beulich 提交于
system_call_after_swapgs doesn't really benefit from forcing alignment from it - quite the opposite, native code needlessly so far got a big NOP instruction inserted in front of it. Xen being the only user of the separate entry point can well live with the branch going to three bytes into a cache line. The compatibility mode ptregs entry points for one can make use of the GLOBAL() macro, and should be suitably aligned. Their shared continuation point (ia32_ptregs_common) otoh doesn't need to be global at all, but should continue to be properly aligned. Signed-off-by: NJan Beulich <jbeulich@suse.com> Reviewed-by: NAndi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/4ED4CEEA020000780006407D@nat28.tlf.novell.comSigned-off-by: NIngo Molnar <mingo@elte.hu>
-
由 Jan Beulich 提交于
GET_THREAD_INFO() involves a memory read immediately followed by an "sub" on the value read, in turn (in several cases) immediately followed by a use of the calculated value as the base address of a memory access. This combination of instructions has a non-negligible potential for stalls. In the system call entry point code, however, the (fixed) offset of the stack pointer from the end of the stack is generally known, and hence we can instead avoid the memory load and subtract, and instead do the memory reference using %rsp as the base register. To do so in a legible fashion, introduce a THREAD_INFO() macro which, provided a register (generally %rsp) and the known offset from the end of the stack, produces a suitable memory access operand. The patch attempts to only touch the fast paths (no auditing and alike), but manages to do so only in the 64-bit entry point case; the compatibility mode entry points have so many interdependencies between their various branch targets that it was necessary to also adjust the slow paths to eliminate the risk of having missed some register dependency during code analysis. Signed-off-by: NJan Beulich <jbeulich@suse.com> Reviewed-by: NAndi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/4ED4CD690200007800064075@nat28.tlf.novell.comSigned-off-by: NIngo Molnar <mingo@elte.hu>
-
- 18 11月, 2011 2 次提交
-
-
由 H. Peter Anvin 提交于
Generate system call tables and unistd_*.h automatically from the tables in arch/x86/syscalls. All other information, like NR_syscalls, is auto-generated, some of which is in asm-offsets_*.c. This allows us to keep all the system call information in one place, and allows for kernel space and user space to see different information; this is currently used for the ia32 system call numbers when building the 64-bit kernel, but will be used by the x32 ABI in the near future. This also removes some gratuitious differences between i386, x86-64 and ia32; in particular, now all system call tables are generated with the same mechanism. Cc: H. J. Lu <hjl.tools@gmail.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
-
由 H. Peter Anvin 提交于
Move compat_ni_syscall out of ia32entry.S and into its own .c file. Although this is a trivial function, it is not performance-critical, and this will simplify further cleanups. Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
-
- 01 11月, 2011 1 次提交
-
-
由 Christopher Yeoh 提交于
The basic idea behind cross memory attach is to allow MPI programs doing intra-node communication to do a single copy of the message rather than a double copy of the message via shared memory. The following patch attempts to achieve this by allowing a destination process, given an address and size from a source process, to copy memory directly from the source process into its own address space via a system call. There is also a symmetrical ability to copy from the current process's address space into a destination process's address space. - Use of /proc/pid/mem has been considered, but there are issues with using it: - Does not allow for specifying iovecs for both src and dest, assuming preadv or pwritev was implemented either the area read from or written to would need to be contiguous. - Currently mem_read allows only processes who are currently ptrace'ing the target and are still able to ptrace the target to read from the target. This check could possibly be moved to the open call, but its not clear exactly what race this restriction is stopping (reason appears to have been lost) - Having to send the fd of /proc/self/mem via SCM_RIGHTS on unix domain socket is a bit ugly from a userspace point of view, especially when you may have hundreds if not (eventually) thousands of processes that all need to do this with each other - Doesn't allow for some future use of the interface we would like to consider adding in the future (see below) - Interestingly reading from /proc/pid/mem currently actually involves two copies! (But this could be fixed pretty easily) As mentioned previously use of vmsplice instead was considered, but has problems. Since you need the reader and writer working co-operatively if the pipe is not drained then you block. Which requires some wrapping to do non blocking on the send side or polling on the receive. In all to all communication it requires ordering otherwise you can deadlock. And in the example of many MPI tasks writing to one MPI task vmsplice serialises the copying. There are some cases of MPI collectives where even a single copy interface does not get us the performance gain we could. For example in an MPI_Reduce rather than copy the data from the source we would like to instead use it directly in a mathops (say the reduce is doing a sum) as this would save us doing a copy. We don't need to keep a copy of the data from the source. I haven't implemented this, but I think this interface could in the future do all this through the use of the flags - eg could specify the math operation and type and the kernel rather than just copying the data would apply the specified operation between the source and destination and store it in the destination. Although we don't have a "second user" of the interface (though I've had some nibbles from people who may be interested in using it for intra process messaging which is not MPI). This interface is something which hardware vendors are already doing for their custom drivers to implement fast local communication. And so in addition to this being useful for OpenMPI it would mean the driver maintainers don't have to fix things up when the mm changes. There was some discussion about how much faster a true zero copy would go. Here's a link back to the email with some testing I did on that: http://marc.info/?l=linux-mm&m=130105930902915&w=2 There is a basic man page for the proposed interface here: http://ozlabs.org/~cyeoh/cma/process_vm_readv.txt This has been implemented for x86 and powerpc, other architecture should mainly (I think) just need to add syscall numbers for the process_vm_readv and process_vm_writev. There are 32 bit compatibility versions for 64-bit kernels. For arch maintainers there are some simple tests to be able to quickly verify that the syscalls are working correctly here: http://ozlabs.org/~cyeoh/cma/cma-test-20110718.tgzSigned-off-by: NChris Yeoh <yeohc@au1.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Howells <dhowells@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: <linux-man@vger.kernel.org> Cc: <linux-arch@vger.kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
- 27 8月, 2011 1 次提交
-
-
由 NeilBrown 提交于
The nfsservctl system call is now gone, so we should remove all linkage for it. Signed-off-by: NNeilBrown <neilb@suse.de> Signed-off-by: NJ. Bruce Fields <bfields@redhat.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
- 04 6月, 2011 2 次提交
-
-
由 Borislav Petkov 提交于
... thus getting rid of the "else" part of the conditional statement in the macro. No functionality change. Signed-off-by: NBorislav Petkov <bp@alien8.de> Link: http://lkml.kernel.org/r/1306873314-32523-4-git-send-email-bp@alien8.deSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>
-
由 Borislav Petkov 提交于
This saves us the else part of the conditional statement in the macro. No functionality change. Signed-off-by: NBorislav Petkov <bp@alien8.de> Link: http://lkml.kernel.org/r/1306873314-32523-3-git-send-email-bp@alien8.deSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>
-
- 29 5月, 2011 1 次提交
-
-
由 Eric W. Biederman 提交于
32bit and 64bit on x86 are tested and working. The rest I have looked at closely and I can't find any problems. setns is an easy system call to wire up. It just takes two ints so I don't expect any weird architecture porting problems. While doing this I have noticed that we have some architectures that are very slow to get new system calls. cris seems to be the slowest where the last system calls wired up were preadv and pwritev. avr32 is weird in that recvmmsg was wired up but never declared in unistd.h. frv is behind with perf_event_open being the last syscall wired up. On h8300 the last system call wired up was epoll_wait. On m32r the last system call wired up was fallocate. mn10300 has recvmmsg as the last system call wired up. The rest seem to at least have syncfs wired up which was new in the 2.6.39. v2: Most of the architecture support added by Daniel Lezcano <dlezcano@fr.ibm.com> v3: ported to v2.6.36-rc4 by: Eric W. Biederman <ebiederm@xmission.com> v4: Moved wiring up of the system call to another patch v5: ported to v2.6.39-rc6 v6: rebased onto parisc-next and net-next to avoid syscall conflicts. v7: ported to Linus's latest post 2.6.39 tree. > arch/blackfin/include/asm/unistd.h | 3 ++- > arch/blackfin/mach-common/entry.S | 1 + Acked-by: NMike Frysinger <vapier@gentoo.org> Oh - ia64 wiring looks good. Acked-by: NTony Luck <tony.luck@intel.com> Signed-off-by: NEric W. Biederman <ebiederm@xmission.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
- 06 5月, 2011 1 次提交
-
-
由 Anton Blanchard 提交于
This patch adds a multiple message send syscall and is the send version of the existing recvmmsg syscall. This is heavily based on the patch by Arnaldo that added recvmmsg. I wrote a microbenchmark to test the performance gains of using this new syscall: http://ozlabs.org/~anton/junkcode/sendmmsg_test.c The test was run on a ppc64 box with a 10 Gbit network card. The benchmark can send both UDP and RAW ethernet packets. 64B UDP batch pkts/sec 1 804570 2 872800 (+ 8 %) 4 916556 (+14 %) 8 939712 (+17 %) 16 952688 (+18 %) 32 956448 (+19 %) 64 964800 (+20 %) 64B raw socket batch pkts/sec 1 1201449 2 1350028 (+12 %) 4 1461416 (+22 %) 8 1513080 (+26 %) 16 1541216 (+28 %) 32 1553440 (+29 %) 64 1557888 (+30 %) We see a 20% improvement in throughput on UDP send and 30% on raw socket send. [ Add sparc syscall entries. -DaveM ] Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
-
- 21 3月, 2011 1 次提交
-
-
由 Sage Weil 提交于
It is frequently useful to sync a single file system, instead of all mounted file systems via sync(2): - On machines with many mounts, it is not at all uncommon for some of them to hang (e.g. unresponsive NFS server). sync(2) will get stuck on those and may never get to the one you do care about (e.g., /). - Some applications write lots of data to the file system and then want to make sure it is flushed to disk. Calling fsync(2) on each file introduces unnecessary ordering constraints that result in a large amount of sub-optimal writeback/flush/commit behavior by the file system. There are currently two ways (that I know of) to sync a single super_block: - BLKFLSBUF ioctl on the block device: That also invalidates the bdev mapping, which isn't usually desirable, and doesn't work for non-block file systems. - 'mount -o remount,rw' will call sync_filesystem as an artifact of the current implemention. Relying on this little-known side effect for something like data safety sounds foolish. Both of these approaches require root privileges, which some applications do not have (nor should they need?) given that sync(2) is an unprivileged operation. This patch introduces a new system call syncfs(2) that takes an fd and syncs only the file system it references. Maybe someday we can $ sync /some/path and not get sync: ignoring all arguments The syscall is motivated by comments by Al and Christoph at the last LSF. syncfs(2) seems like an appropriate name given statfs(2). A similar ioctl was also proposed a while back, see http://marc.info/?l=linux-fsdevel&m=127970513829285&w=2Signed-off-by: NSage Weil <sage@newdream.net> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
-
- 15 3月, 2011 1 次提交
-
-
由 Aneesh Kumar K.V 提交于
This patch add new syscalls to x86_64 Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
-
- 09 3月, 2011 1 次提交
-
-
由 Jiri Olsa 提交于
Put x86 entry code into a separate link section: .entry.text. Separating the entry text section seems to have performance benefits - caused by more efficient instruction cache usage. Running hackbench with perf stat --repeat showed that the change compresses the icache footprint. The icache load miss rate went down by about 15%: before patch: 19417627 L1-icache-load-misses ( +- 0.147% ) after patch: 16490788 L1-icache-load-misses ( +- 0.180% ) The motivation of the patch was to fix a particular kprobes bug that relates to the entry text section, the performance advantage was discovered accidentally. Whole perf output follows: - results for current tip tree: Performance counter stats for './hackbench/hackbench 10' (500 runs): 19417627 L1-icache-load-misses ( +- 0.147% ) 2676914223 instructions # 0.497 IPC ( +- 0.079% ) 5389516026 cycles ( +- 0.144% ) 0.206267711 seconds time elapsed ( +- 0.138% ) - results for current tip tree with the patch applied: Performance counter stats for './hackbench/hackbench 10' (500 runs): 16490788 L1-icache-load-misses ( +- 0.180% ) 2717734941 instructions # 0.502 IPC ( +- 0.079% ) 5414756975 cycles ( +- 0.148% ) 0.206747566 seconds time elapsed ( +- 0.137% ) Signed-off-by: NJiri Olsa <jolsa@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: masami.hiramatsu.pt@hitachi.com Cc: ananth@in.ibm.com Cc: davem@davemloft.net Cc: 2nddept-manager@sdl.hitachi.co.jp LKML-Reference: <20110307181039.GB15197@jolsa.redhat.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
-
- 01 3月, 2011 1 次提交
-
-
由 Jan Beulich 提交于
Cleaning up and shortening code... Signed-off-by: NJan Beulich <jbeulich@novell.com> Cc: Alexander van Heukelum <heukelum@fastmail.fm> LKML-Reference: <4D6BD35002000078000341DA@vpn.id2.novell.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
-
- 02 2月, 2011 1 次提交
-
-
由 Richard Cochran 提交于
This patch adds the clock_adjtime system call to the x86 architecture. Signed-off-by: NRichard Cochran <richard.cochran@omicron.at> Acked-by: NJohn Stultz <johnstul@us.ibm.com> LKML-Reference: <20110201134419.968905083@linutronix.de> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
-
- 15 9月, 2010 2 次提交
-
-
由 Roland McGrath 提交于
In commit d4d67150, we reopened an old hole for a 64-bit ptracer touching a 32-bit tracee in system call entry. A %rax value set via ptrace at the entry tracing stop gets used whole as a 32-bit syscall number, while we only check the low 32 bits for validity. Fix it by truncating %rax back to 32 bits after syscall_trace_enter, in addition to testing the full 64 bits as has already been added. Reported-by: NBen Hawkes <hawkes@sota.gen.nz> Signed-off-by: NRoland McGrath <roland@redhat.com> Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
-
由 H. Peter Anvin 提交于
On 64 bits, we always, by necessity, jump through the system call table via %rax. For 32-bit system calls, in theory the system call number is stored in %eax, and the code was testing %eax for a valid system call number. At one point we loaded the stored value back from the stack to enforce zero-extension, but that was removed in checkin d4d67150. An actual 32-bit process will not be able to introduce a non-zero-extended number, but it can happen via ptrace. Instead of re-introducing the zero-extension, test what we are actually going to use, i.e. %rax. This only adds a handful of REX prefixes to the code. Reported-by: NBen Hawkes <hawkes@sota.gen.nz> Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com> Cc: <stable@kernel.org> Cc: Roland McGrath <roland@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org>
-
- 11 8月, 2010 1 次提交
-
-
由 Linus Torvalds 提交于
As pointed out by Jiri Slaby: when I resolved the the 32-bit x85 system call entry tables for prlimit (due to the conflict with fanotify), I forgot to add the numbering in comments that we do for every fifth entry. Reported-by: NJiri Slaby <jslaby@suse.cz> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
- 28 7月, 2010 2 次提交
-
-
由 Eric Paris 提交于
This patch simply declares the new sys_fanotify_mark syscall int fanotify_mark(int fanotify_fd, unsigned int flags, u64_mask, int dfd const char *pathname) Signed-off-by: NEric Paris <eparis@redhat.com>
-
由 Eric Paris 提交于
This patch defines a new syscall fanotify_init() of the form: int sys_fanotify_init(unsigned int flags, unsigned int event_f_flags, unsigned int priority) This syscall is used to create and fanotify group. This is very similar to the inotify_init() syscall. Signed-off-by: NEric Paris <eparis@redhat.com>
-
- 16 7月, 2010 1 次提交
-
-
由 Jiri Slaby 提交于
Add __NR_prlimit64 syscall numbers to asm-generic. Add them also to asm-x86, both 32 and 64-bit. Signed-off-by: NJiri Slaby <jslaby@suse.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com>
-
- 21 4月, 2010 1 次提交
-
-
由 Christoph Hellwig 提交于
Before commit e28cbf22 ("improve sys_newuname() for compat architectures") 64-bit x86 had a private implementation of sys_uname which was just called sys_uname, which other architectures used for the old uname. Due to some merge issues with the uname refactoring patches we ended up calling the old uname version for both the old and new system call slots, which lead to the domainname filed never be set which caused failures with libnss_nis. Reported-and-tested-by: NAndy Isaacson <adi@hexapodia.org> Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-