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2010-12-17arch/tile: handle rt_sigreturn() more cleanlyChris Metcalf
The current tile rt_sigreturn() syscall pattern uses the common idiom of loading up pt_regs with all the saved registers from the time of the signal, then anticipating the fact that we will clobber the ABI "return value" register (r0) as we return from the syscall by setting the rt_sigreturn return value to whatever random value was in the pt_regs for r0. However, this breaks in our 64-bit kernel when running "compat" tasks, since we always sign-extend the "return value" register to properly handle returned pointers that are in the upper 2GB of the 32-bit compat address space. Doing this to the sigreturn path then causes occasional random corruption of the 64-bit r0 register. Instead, we stop doing the crazy "load the return-value register" hack in sigreturn. We already have some sigreturn-specific assembly code that we use to pass the pt_regs pointer to C code. We extend that code to also set the link register to point to a spot a few instructions after the usual syscall return address so we don't clobber the saved r0. Now it no longer matters what the rt_sigreturn syscall returns, and the pt_regs structure can be cleanly and completely reloaded. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-12-17arch/tile: handle CLONE_SETTLS in copy_thread(), not user spaceChris Metcalf
Previously we were just setting up the "tp" register in the new task as started by clone() in libc. However, this is not quite right, since in principle a signal might be delivered to the new task before it had its TLS set up. (Of course, this race window still exists for resetting the libc getpid() cached value in the new task, in principle. But in any case, we are now doing this exactly the way all other architectures do it.) This change is important for 2.6.37 since the tile glibc we will be submitting upstream will not set TLS in user space any more, so it will only work on a kernel that has this fix. It should also be taken for 2.6.36.x in the stable tree if possible. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Cc: stable <stable@kernel.org>
2010-11-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tileLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: arch/tile: fix memchr() not to dereference memory for zero length arch/tile: make glibc's sysconf(_SC_NPROCESSORS_CONF) work correctly arch/tile: fix rwlock so would-be write lockers don't block new readers
2010-11-24Merge branch 'drivers' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile * 'drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: pci root complex: support for tile architecture drivers/net/tile/: on-chip network drivers for the tile architecture MAINTAINERS: add drivers/char/hvc_tile.c as maintained by tile
2010-11-24arch/tile: fix memchr() not to dereference memory for zero lengthChris Metcalf
This change fixes a bug that memchr() will read the first word of the source even if the length is zero. Ironically, the code was originally written with a test to avoid exactly this problem, but to make the code conform to Linux coding standards with all declarations preceding all statements, the first load from memory was moved up above that test as the initial value for a variable. The change just moves all the variable declarations to the top of the file, with no initializers, so that the test can also be at the top of the file. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-11-24arch/tile: make glibc's sysconf(_SC_NPROCESSORS_CONF) work correctlyChris Metcalf
glibc assumes that it can count /sys/devices/system/cpu/cpu* to get the number of configured cpus. For this to be valid on tile, we need to generate a "cpu" entry for all cpus, including the ones that are not currently allocated for Linux's use. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-11-24Merge branch 'master' into for-linusChris Metcalf
2010-11-24pci root complex: support for tile architectureChris Metcalf
This change enables PCI root complex support for TILEPro. Unlike TILE-Gx, TILEPro has no support for memory-mapped I/O, so the PCI support consists of hypervisor upcalls for PIO, DMA, etc. However, the performance is fine for the devices we have tested with so far (1Gb Ethernet, SATA, etc.). The <asm/io.h> header was tweaked to be a little bit more aggressive about disabling attempts to map/unmap IO port space. The hacky <asm/pci-bridge.h> header was rolled into the <asm/pci.h> header and the result was simplified. Both of the latter two headers were preliminary versions not meant for release before now - oh well. There is one quirk for our TILEmpower platform, which accidentally negotiates up to 5GT and needs to be kicked down to 2.5GT. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-11-24drivers/net/tile/: on-chip network drivers for the tile architectureChris Metcalf
This change adds the first network driver for the tile architecture, supporting the on-chip XGBE and GBE shims. The infrastructure is present for the TILE-Gx networking drivers (another three source files in the new directory) but for now the the actual tilegx sources are waiting on releasing hardware to initial customers. Note that arch/tile/include/hv/* are "upstream" headers from the Tilera hypervisor and will probably benefit less from LKML review. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-11-17BKL: remove extraneous #include <smp_lock.h>Arnd Bergmann
The big kernel lock has been removed from all these files at some point, leaving only the #include. Remove this too as a cleanup. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-15arch/tile: fix rwlock so would-be write lockers don't block new readersChris Metcalf
This avoids a deadlock in the IGMP code where one core gets a read lock, another core starts trying to get a write lock (thus blocking new readers), and then the first core tries to recursively re-acquire the read lock. We still try to preserve some degree of balance by giving priority to additional write lockers that come along while the lock is held for write, so they can all complete quickly and return the lock to the readers. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-11-01arch/tile: mark "hardwall" device as non-seekableChris Metcalf
Arnd's recent patch series tagged this device with noop_llseek, conservatively. In fact, it should be no_llseek, which we arrange for by opening the device with nonseekable_open(). Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-11-01asm-generic/stat.h: support 64-bit file time_t for stat()Chris Metcalf
The existing asm-generic/stat.h specifies st_mtime, etc., as a 32-value, and works well for 32-bit architectures (currently microblaze, score, and 32-bit tile). However, for 64-bit architectures it isn't sufficient to return 32 bits of time_t; this isn't good insurance against the 2037 rollover. (It also makes glibc support less convenient, since we can't use glibc's handy STAT_IS_KERNEL_STAT mode.) This change extends the two "timespec" fields for each of the three atime, mtime, and ctime fields from "int" to "long". As a result, on 32-bit platforms nothing changes, and 64-bit platforms will now work as expected. The only wrinkle is 32-bit userspace under 64-bit kernels taking advantage of COMPAT mode. For these, we leave the "struct stat64" definitions with the "int" versions of the time_t and nsec fields, so that architectures can implement compat_sys_stat64() and friends with sys_stat64(), etc., and get the expected 32-bit structure layout. This requires a field-by-field copy in the kernel, implemented by the code guarded under __ARCH_WANT_STAT64. This does mean that the shape of the "struct stat" and "struct stat64" structures is different on a 64-bit kernel, but only one of the two structures should ever be used by any given process: "struct stat" is meant for 64-bit userspace only, and "struct stat64" for 32-bit userspace only. (On a 32-bit kernel the two structures continue to have the same shape, since "long" is 32 bits.) The alternative is keeping the two structures the same shape on 64-bit kernels, which means a 64-bit time_t in "struct stat64" for 32-bit processes. This is a little unnatural since 32-bit userspace can't do anything with 64 bits of time_t information, since time_t is just "long", not "int64_t"; and in any case 32-bit userspace might expect to be running under a 32-bit kernel, which can't provide the high 32 bits anyway. In the case of a 32-bit kernel we'd then be extending the kernel's 32-bit time_t to 64 bits, then truncating it back to 32 bits again in userspace, for no particular reason. And, as mentioned above, if we have 64-bit time_t for 32-bit processes we can't easily use glibc's STAT_IS_KERNEL_STAT, since glibc's stat structure requires an embedded "struct timespec", which is a pair of "long" (32-bit) values in a 32-bit userspace. "Inventive" solutions are possible, but are pretty hacky. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2010-11-01arch/tile: don't allow user code to set the PL via ptrace or signal returnChris Metcalf
The kernel was allowing any component of the pt_regs to be updated either by signal handlers writing to the stack, or by processes writing via PTRACE_POKEUSR or PTRACE_SETREGS, which meant they could set their PL up from 0 to 1 and get access to kernel code and data (or, in practice, cause a kernel panic). We now always reset the ex1 field, allowing the user to set their ICS bit only. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-11-01arch/tile: correct double syscall restart for nested signalsChris Metcalf
This change is modelled on similar fixes for other architectures. The pt_regs "faultnum" member is set to the trap (fault) number that caused us to enter the kernel, and is INT_SWINT_1 for the syscall software interrupt. We already supported a pseudo value, INT_SWINT_1_SIGRETURN, that we used for the rt_sigreturn syscall; it avoided the case where one signal was handled, then we "tail-called" to another handler. This change avoids the similar case where we start to call one handler, then are preempted into another handler when we start trying to run the first handler. We clear ->faultnum after calling handle_signal(), and to be paranoid also in the case where there was no signal to deliver. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-11-01arch/tile: avoid __must_check warning on one strict_strtol checkChris Metcalf
For the "initfree" boot argument it's not that big a deal, but to avoid warnings in the code, we check for a valid value before allowing the specified argument to override the kernel default. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-11-01arch/tile: bomb raw_local_irq_ to arch_local_irq_Chris Metcalf
This completes the tile migration to the new naming scheme for the architecture-specific irq management code. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-11-01arch/tile: complete migration to new kmap_atomic schemeChris Metcalf
This change makes KM_TYPE_NR independent of the actual deprecated list of km_type values, which are no longer used in tile code anywhere. For now we leave it set to 8, allowing that many nested mappings, and thus reserving 32MB of address space. A few remaining places using KM_* values were cleaned up as well. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-28Merge branch 'kconfig' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6 * 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6: (38 commits) kbuild: convert `arch/tile' to the kconfig mainmenu upgrade README: cite nconfig Revert "kconfig: Temporarily disable dependency warnings" kconfig: Use PATH_MAX instead of 128 for path buffer sizes. kconfig: Fix realloc usage() kconfig: Propagate const kconfig: Don't go out from read config loop when you read new symbol kconfig: fix menuconfig on debian lenny kbuild: migrate all arch to the kconfig mainmenu upgrade kconfig: expand file names kconfig: use the file's name of sourced file kconfig: constify file name kconfig: don't emit warning upon rootmenu's prompt redefinition kconfig: replace KERNELVERSION usage by the mainmenu's prompt kconfig: delay gconf window initialization kconfig: expand by default the rootmenu's prompt kconfig: add a symbol string expansion helper kconfig: regen parser kconfig: implement the `mainmenu' directive kconfig: allow PACKAGE to be defined on the compiler's command-line ... Fix up trivial conflict in arch/mn10300/Kconfig
2010-10-28kbuild: convert `arch/tile' to the kconfig mainmenu upgradeArnaud Lacombe
Signed-off-by: Arnaud Lacombe <lacombar@gmail.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-10-28Remove duplicate includes from many filesZimny Lech
Signed-off-by: Zimny Lech <napohybelskurwysynom2010@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-28ptrace: cleanup arch_ptrace() on tileNamhyung Kim
Remove checking @addr less than 0 because @addr is now unsigned. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Acked-by: Chris Metcalf <cmetcalf@tilera.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-28ptrace: change signature of arch_ptrace()Namhyung Kim
Fix up the arguments to arch_ptrace() to take account of the fact that @addr and @data are now unsigned long rather than long as of a preceding patch in this series. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Cc: <linux-arch@vger.kernel.org> Acked-by: Roland McGrath <roland@redhat.com> Acked-by: David Howells <dhowells@redhat.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-28tile: enable ARCH_DMA_ADDR_T_64BITFUJITA Tomonori
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Acked-by: Chris Metcalf <cmetcalf@tilera.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-28mm: fix race in kunmap_atomic()Peter Zijlstra
Christoph reported a nice splat which illustrated a race in the new stack based kmap_atomic implementation. The problem is that we pop our stack slot before we're completely done resetting its state -- in particular clearing the PTE (sometimes that's CONFIG_DEBUG_HIGHMEM). If an interrupt happens before we actually clear the PTE used for the last slot, that interrupt can reuse the slot in a dirty state, which triggers a BUG in kmap_atomic(). Fix this by introducing kmap_atomic_idx() which reports the current slot index without actually releasing it and use that to find the PTE and delay the _pop() until after we're completely done. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reported-by: Christoph Hellwig <hch@infradead.org> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tileLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: arch/tile: convert a BUG_ON to BUILD_BUG_ON arch/tile: make ptrace() work properly for TILE-Gx COMPAT mode arch/tile: support new info op generated by compiler arch/tile: minor whitespace/naming changes for string support files arch/tile: enable single-step support for TILE-Gx arch/tile: parameterize system PLs to support KVM port arch/tile: add Tilera's <arch/sim.h> header as an open-source header arch/tile: Bomb C99 comments to C89 comments in tile's <arch/sim_def.h> arch/tile: prevent corrupt top frame from causing backtracer runaway arch/tile: various top-level Makefile cleanups arch/tile: change lower bound on syscall error return to -4095 arch/tile: properly export __mb_incoherent for modules arch/tile: provide a definition of MAP_STACK kmemleak: add TILE to the list of supported architectures. char: hvc: check for error case arch/tile: Add a warning if we try to allocate too much vmalloc memory. arch/tile: update some comments to clarify register usage. arch/tile: use better "punctuation" for VMSPLIT_3_5G and friends arch/tile: Use <asm-generic/syscalls.h> tile: replace some BUG_ON checks with BUILD_BUG_ON checks
2010-10-26mm: remove pte_*map_nested()Peter Zijlstra
Since we no longer need to provide KM_type, the whole pte_*map_nested() API is now redundant, remove it. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Chris Metcalf <cmetcalf@tilera.com> Cc: David Howells <dhowells@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Miller <davem@davemloft.net> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26mm: stack based kmap_atomic()Peter Zijlstra
Keep the current interface but ignore the KM_type and use a stack based approach. The advantage is that we get rid of crappy code like: #define __KM_PTE \ (in_nmi() ? KM_NMI_PTE : \ in_irq() ? KM_IRQ_PTE : \ KM_PTE0) and in general can stop worrying about what context we're in and what kmap slots might be appropriate for that. The downside is that FRV kmap_atomic() gets more expensive. For now we use a CPP trick suggested by Andrew: #define kmap_atomic(page, args...) __kmap_atomic(page) to avoid having to touch all kmap_atomic() users in a single patch. [ not compiled on: - mn10300: the arch doesn't actually build with highmem to begin with ] [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: fix up drivers/gpu/drm/i915/intel_overlay.c] Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Chris Metcalf <cmetcalf@tilera.com> Cc: David Howells <dhowells@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Miller <davem@davemloft.net> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dave Airlie <airlied@linux.ie> Cc: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-genericLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: asm-generic/io.h: allow people to override individual funcs bitops: remove duplicated extern declarations bitops: make asm-generic/bitops/find.h more generic asm-generic: kdebug.h: Checkpatch cleanup asm-generic: fcntl: make exported headers use strict posix types asm-generic: cmpxchg does not handle non-long arguments asm-generic: make atomic_add_unless a function
2010-10-22Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bklLinus Torvalds
* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl: vfs: make no_llseek the default vfs: don't use BKL in default_llseek llseek: automatically add .llseek fop libfs: use generic_file_llseek for simple_attr mac80211: disallow seeks in minstrel debug code lirc: make chardev nonseekable viotape: use noop_llseek raw: use explicit llseek file operations ibmasmfs: use generic_file_llseek spufs: use llseek in all file operations arm/omap: use generic_file_llseek in iommu_debug lkdtm: use generic_file_llseek in debugfs net/wireless: use generic_file_llseek in debugfs drm: use noop_llseek
2010-10-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-irqflagsLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-irqflags: Fix IRQ flag handling naming MIPS: Add missing #inclusions of <linux/irq.h> smc91x: Add missing #inclusion of <linux/irq.h> Drop a couple of unnecessary asm/system.h inclusions SH: Add missing consts to sys_execve() declaration Blackfin: Rename IRQ flags handling functions Blackfin: Add missing dep to asm/irqflags.h Blackfin: Rename DES PC2() symbol to avoid collision Blackfin: Split the BF532 BFIN_*_FIO_FLAG() functions to their own header Blackfin: Split PLL code from mach-specific cdef headers
2010-10-15arch/tile: convert a BUG_ON to BUILD_BUG_ONChris Metcalf
Inspired by Akinobu Mita's cleanup work. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-15arch/tile: make ptrace() work properly for TILE-Gx COMPAT modeChris Metcalf
Previously, we tried to pass 64-bit arguments through the "COMPAT" mode 32-bit syscall API, which turned out not to work well. Now we just use straight 32-bit arguments in COMPAT mode, thus requiring individual registers to be read/written with two syscalls. Of course this is uncommon, since usually all the registers are read or written at once. The restructuring applies to all the tile platforms, but is plausibly better than the original code in any case. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-15arch/tile: support new info op generated by compilerChris Metcalf
This just syncs the backtracing support in the kernel to the upstream backtrace library. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-15arch/tile: minor whitespace/naming changes for string support filesChris Metcalf
Our internal process shares memcpy, memset, etc., with libc, and we did some minor tweaking as part of moving from uclibc to glibc, which is now reflected in the kernel versions of these files. There are no semantic changes in this commit, just whitespace (memcpy_32.S now properly uses tabs), naming (memmove.c instead of memmove_32.c, since TILE-Gx shares the file with TILEPro), and a couple of other minor tweaks. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-15arch/tile: enable single-step support for TILE-GxChris Metcalf
This is not quite the complete support, since we're not yet shipping intvec_64.S, but it is the support relevant to the set of files we are currently shipping, and makes it easier to track changes between our internal sources and our public GIT repository. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-15arch/tile: parameterize system PLs to support KVM portChris Metcalf
While not a port to KVM (yet), this change modifies the kernel to be able to build either at PL1 or at PL2 with a suitable config switch. Pushing up this change avoids handling branch merge issues going forward with the KVM work. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-15arch/tile: add Tilera's <arch/sim.h> header as an open-source headerChris Metcalf
This change adds one of the Tilera standard <arch> headers to the set of headers shipped with Linux. The <arch/sim.h> header provides methods for programmatically interacting with the Tilera simulator. The current <arch/sim.h> provides inline assembly for the _sim_syscall function, so the declaration and definition previously provided manually in Linux are no longer needed. We now use the standard sim_validate_lines_evicted() method from <arch/sim.h> rather than rolling our own direct call to sim_syscall(). Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-15arch/tile: Bomb C99 comments to C89 comments in tile's <arch/sim_def.h>Chris Metcalf
Also, sync the file up the upstream version (an additional #define). Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-15llseek: automatically add .llseek fopArnd Bergmann
All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
2010-10-14arch/tile: prevent corrupt top frame from causing backtracer runawayChris Metcalf
The backtracer will normally cut itself off after 100 frames anyway, but it's messy. With this change we notice that the frame being reported is the same as the last one, and cut off the dump with a message similar to what gdb displays in the same circumstance. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-14arch/tile: various top-level Makefile cleanupsChris Metcalf
Avoid a compile failure if CONFIG_DEBUG_EXTRA_FLAGS is empty (""); provide an "install" hook as well as a matching archhelp target; and some minor whitespace cleanup. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-14arch/tile: change lower bound on syscall error return to -4095Chris Metcalf
Previously we were using -1023, which is fine for normal syscall error returns, but the common value in use for other platforms is -4095, and one Tilera-specific driver does use values in the -1100 range, so tickled this bug. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-14arch/tile: properly export __mb_incoherent for modulesChris Metcalf
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-14arch/tile: provide a definition of MAP_STACKChris Metcalf
It's convenient for userspace (in particular, glibc) to find a definition of MAP_STACK. We use MAP_GROWSDOWN as an alias since that's appropriate for the main stack, and since our current allocation of mmap flags bits is running a bit short otherwise. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-14arch/tile: Add a warning if we try to allocate too much vmalloc memory.Chris Metcalf
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-14arch/tile: update some comments to clarify register usage.Chris Metcalf
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-14arch/tile: use better "punctuation" for VMSPLIT_3_5G and friendsChris Metcalf
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-14arch/tile: Use <asm-generic/syscalls.h>Chris Metcalf
With this change we now include <asm-generic/syscalls.h> into the "tile" version of the header. To take full advantage of the prototypes there, we also change our naming convention for "struct pt_regs *" syscalls so that, e.g., _sys_execve() is the "true" syscall entry, which sets the appropriate register to point to the pt_regs before calling sys_execve(). While doing this I realized I no longer needed the fork and vfork entry point stubs, since those functions aren't in the generic syscall ABI, so I removed them as well. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-14Merge branch 'master' into for-linusChris Metcalf