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2020-10-21treewide: remove DISABLE_LTOSami Tolvanen
This change removes all instances of DISABLE_LTO from Makefiles, as they are currently unused, and the preferred method of disabling LTO is to filter out the flags instead. Note added by Masahiro Yamada: DISABLE_LTO was added as preparation for GCC LTO, but GCC LTO was not pulled into the mainline. (https://lkml.org/lkml/2014/4/8/272) Suggested-by: Kees Cook <keescook@chromium.org> Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-10-09kbuild: explicitly specify the build id styleBill Wendling
ld's --build-id defaults to "sha1" style, while lld defaults to "fast". The build IDs are very different between the two, which may confuse programs that reference them. Signed-off-by: Bill Wendling <morbo@google.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-07-07kbuild: remove cc-option test of -fno-stack-protectorMasahiro Yamada
Some Makefiles already pass -fno-stack-protector unconditionally. For example, arch/arm64/kernel/vdso/Makefile, arch/x86/xen/Makefile. No problem report so far about hard-coding this option. So, we can assume all supported compilers know -fno-stack-protector. GCC 4.8 and Clang support this option (https://godbolt.org/z/_HDGzN) Get rid of cc-option from -fno-stack-protector. Remove CONFIG_CC_HAS_STACKPROTECTOR_NONE, which is always 'y'. Note: arch/mips/vdso/Makefile adds -fno-stack-protector twice, first unconditionally, and second conditionally. I removed the second one. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2020-06-09mmap locking API: use coccinelle to convert mmap_sem rwsem call sitesMichel Lespinasse
This change converts the existing mmap_sem rwsem calls to use the new mmap locking API instead. The change is generated using coccinelle with the following rule: // spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir . @@ expression mm; @@ ( -init_rwsem +mmap_init_lock | -down_write +mmap_write_lock | -down_write_killable +mmap_write_lock_killable | -down_write_trylock +mmap_write_trylock | -up_write +mmap_write_unlock | -downgrade_write +mmap_write_downgrade | -down_read +mmap_read_lock | -down_read_killable +mmap_read_lock_killable | -down_read_trylock +mmap_read_trylock | -up_read +mmap_read_unlock ) -(&mm->mmap_sem) +(mm) Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-07sparc,x86: vdso: remove meaningless undefining CONFIG_OPTIMIZE_INLININGMasahiro Yamada
The code, #undef CONFIG_OPTIMIZE_INLINING, is not working as expected because <linux/compiler_types.h> is parsed before vclock_gettime.c since 28128c61e08e ("kconfig.h: Include compiler types to avoid missed struct attributes"). Since then, <linux/compiler_types.h> is included really early by using the '-include' option. So, you cannot negate the decision of <linux/compiler_types.h> in this way. You can confirm it by checking the pre-processed code, like this: $ make arch/x86/entry/vdso/vdso32/vclock_gettime.i There is no difference with/without CONFIG_CC_OPTIMIZE_FOR_SIZE. It is about two years since 28128c61e08e. Nobody has reported a problem (or, nobody has even noticed the fact that this code is not working). It is ugly and unreliable to attempt to undefine a CONFIG option from C files, and anyway the inlining heuristic is up to the compiler. Just remove the broken code. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Acked-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: David Miller <davem@davemloft.net> Link: http://lkml.kernel.org/r/20200220110807.32534-1-masahiroy@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-03-25.gitignore: add SPDX License IdentifierMasahiro Yamada
Add SPDX License Identifier to all .gitignore files. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-04kbuild: rename hostprogs-y/always to hostprogs/always-yMasahiro Yamada
In old days, the "host-progs" syntax was used for specifying host programs. It was renamed to the current "hostprogs-y" in 2004. It is typically useful in scripts/Makefile because it allows Kbuild to selectively compile host programs based on the kernel configuration. This commit renames like follows: always -> always-y hostprogs-y -> hostprogs So, scripts/Makefile will look like this: always-$(CONFIG_BUILD_BIN2C) += ... always-$(CONFIG_KALLSYMS) += ... ... hostprogs := $(always-y) $(always-m) I think this makes more sense because a host program is always a host program, irrespective of the kernel configuration. We want to specify which ones to compile by CONFIG options, so always-y will be handier. The "always", "hostprogs-y", "hostprogs-m" will be kept for backward compatibility for a while. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2019-12-01Merge tag 'y2038-cleanups-5.5' of ↵Linus Torvalds
git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground Pull y2038 cleanups from Arnd Bergmann: "y2038 syscall implementation cleanups This is a series of cleanups for the y2038 work, mostly intended for namespace cleaning: the kernel defines the traditional time_t, timeval and timespec types that often lead to y2038-unsafe code. Even though the unsafe usage is mostly gone from the kernel, having the types and associated functions around means that we can still grow new users, and that we may be missing conversions to safe types that actually matter. There are still a number of driver specific patches needed to get the last users of these types removed, those have been submitted to the respective maintainers" Link: https://lore.kernel.org/lkml/20191108210236.1296047-1-arnd@arndb.de/ * tag 'y2038-cleanups-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground: (26 commits) y2038: alarm: fix half-second cut-off y2038: ipc: fix x32 ABI breakage y2038: fix typo in powerpc vdso "LOPART" y2038: allow disabling time32 system calls y2038: itimer: change implementation to timespec64 y2038: move itimer reset into itimer.c y2038: use compat_{get,set}_itimer on alpha y2038: itimer: compat handling to itimer.c y2038: time: avoid timespec usage in settimeofday() y2038: timerfd: Use timespec64 internally y2038: elfcore: Use __kernel_old_timeval for process times y2038: make ns_to_compat_timeval use __kernel_old_timeval y2038: socket: use __kernel_old_timespec instead of timespec y2038: socket: remove timespec reference in timestamping y2038: syscalls: change remaining timeval to __kernel_old_timeval y2038: rusage: use __kernel_old_timeval y2038: uapi: change __kernel_time_t to __kernel_old_time_t y2038: stat: avoid 'time_t' in 'struct stat' y2038: ipc: remove __kernel_time_t reference from headers y2038: vdso: powerpc: avoid timespec references ...
2019-11-15y2038: vdso: change timespec to __kernel_old_timespecArnd Bergmann
In order to remove 'timespec' completely from the kernel, all internal uses should be converted to a y2038-safe type, while those that are only for compatibity with existing user space should be marked appropriately. Change vdso to use __kernel_old_timespec in order to avoid the deprecated type and mark these interfaces as outdated. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-11-15y2038: vdso: change timeval to __kernel_old_timevalArnd Bergmann
The gettimeofday() function in vdso uses the traditional 'timeval' structure layout, which will be incompatible with future versions of glibc on 32-bit architectures that use a 64-bit time_t. This interface is problematic for y2038, when time_t overflows on 32-bit architectures, but the plan so far is that a libc with 64-bit time_t will not call into the gettimeofday() vdso helper at all, and only have a method for entering clock_gettime(). This means we don't have to fix it here, though we probably want to add a new clock_gettime() entry point using a 64-bit version of 'struct timespec' at some point. Changing the vdso code to use __kernel_old_timeval helps isolate this usage from the other ones that still need to be fixed properly, and it gets us closer to removing the 'timeval' definition from the kernel sources. Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-11-15sparc: vdso: fix build error of vdso32Masahiro Yamada
Since commit 54b8ae66ae1a ("kbuild: change *FLAGS_<basetarget>.o to take the path relative to $(obj)"), sparc allmodconfig fails to build as follows: CC arch/sparc/vdso/vdso32/vclock_gettime.o unrecognized e_machine 18 arch/sparc/vdso/vdso32/vclock_gettime.o arch/sparc/vdso/vdso32/vclock_gettime.o: failed The cause of the breakage is that -pg flag not being dropped. The vdso32 files are located in the vdso32/ subdirectory, but I missed to update the Makefile. I removed the meaningless CFLAGS_REMOVE_vdso-note.o since it is only effective for C file. vdso-note.o is compiled from assembly file: arch/sparc/vdso/vdso-note.S arch/sparc/vdso/vdso32/vdso-note.S Fixes: 54b8ae66ae1a ("kbuild: change *FLAGS_<basetarget>.o to take the path relative to $(obj)") Reported-by: Anatoly Pugachev <matorola@gmail.com> Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Tested-by: Anatoly Pugachev <matorola@gmail.com> Acked-by: David S. Miller <davem@davemloft.net>
2019-07-17kbuild: add --hash-style= and --build-id unconditionallyMasahiro Yamada
As commit 1e0221374e30 ("mips: vdso: drop unnecessary cc-ldoption") explained, these flags are supported by the minimal required version of binutils. They are supported by ld.lld too. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Tested-by: Nathan Chancellor <natechancellor@gmail.com>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 223Thomas Gleixner
Based on 1 normalized pattern(s): subject to the gnu public license v 2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 9 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Steve Winslow <swinslow@gmail.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190528171440.130801526@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 214Thomas Gleixner
Based on 1 normalized pattern(s): subject to the gpl v 2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 2 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Steve Winslow <swinslow@gmail.com> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190528171439.372657724@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21treewide: Add SPDX license identifier - Makefile/KconfigThomas Gleixner
Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-08sparc: vdso: add FORCE to the build rule of %.soMasahiro Yamada
$(call if_changed,...) must have FORCE as a prerequisite. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-21sparc: vdso: Drop implicit common-page-size linker flagndesaulniers@google.com
GNU linker's -z common-page-size's default value is based on the target architecture. arch/sparc/vdso/Makefile sets it to the architecture default, which is implicit and redundant. Drop it. Link: https://lkml.kernel.org/r/20181206191231.192355-1-ndesaulniers@google.com Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-25sparc: Fix VDSO build with older binutils.David S. Miller
Older versions of bintutils do not allow symbol math across different segments on sparc: ==================== Assembler messages: 99: Error: operation combines symbols in different segments ==================== This is controlled by whether or not DIFF_EXPR_OK is defined in gas/config/tc-*.h and for sparc this was not the case until mid-2017. So we have to patch between %stick and %tick another way. Do what powerpc does and emit two versions of the relevant functions, one using %tick and one using %stick, and patch the symbols in the dynamic symbol table. Fixes: 2f6c9bf31a0b ("sparc: Improve VDSO instruction patching.") Reported-by: Meelis Roos <mroos@linux.ee> Tested-by: Meelis Roos <mroos@linux.ee> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-22sparc: Several small VDSO vclock_gettime.c improvements.David S. Miller
Almost entirely borrowed from the x86 code. Main improvement is to avoid having to initialize ts->tv_nsec to zero before the sequence loops, by expanding timespec_add_ns(). Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-22sparc: Validate VDSO for undefined symbols.David S. Miller
There should be no undefined symbols in the resulting VDSO image(s). On sparc, fixed register usage can result in undefined symbols ending up in the image. To combat this, we do two things: 1) Define current_thread_info() specially when BUILD_DSO. 2) Ignore "#scratch" register undefined symbols in the output. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-22sparc: Really use linker with LDFLAGS.David S. Miller
Rather than funneling through CC. Also, use --hash-style=both just like other VDSO architectures and glibc do. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-22sparc: Improve VDSO CFLAGS.David S. Miller
Do not set any special register usage options, use the default which is exactly what we should use for userspace code. Make sure we remove the gcc plugin options from the 64-bit build. The 32-bit cflags got it right already. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-22sparc: Set DISABLE_BRANCH_PROFILING in VDSO CFLAGS.David S. Miller
Not in vclock_gettime.c itself. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-22sparc: Don't bother masking out TICK_PRIV_BIT in VDSO code.David S. Miller
If the TICK_PRIV_BIT was set, we would not be able to read the tick register in user space, which is where this code runs. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-22sparc: Inline VDSO gettime code aggressively.David S. Miller
One interesting thing we need to do is stop using __builtin_return_address() in get_vvar_data(). Simply read the %pc register instead. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-22sparc: Improve VDSO instruction patching.David S. Miller
The current VDSO patch mechanism has several problems: 1) It assumes how gcc will emit a function, with a register window, an initial save instruction and then immediately the %tick read when compiling vread_tick(). There is no such guarantees, code generation could change at any time, gcc could put a nop between the save and the %tick read, etc. So this is extremely fragile and would fail some day. 2) It disallows us to properly inline vread_tick() into the callers and thus get the best possible code sequences. So fix this to patch properly, with location based annotations. We have to be careful because we cannot do it the way we do patches elsewhere in the kernel. Those use a sequence like: 1: insn .section .whatever_patch, "ax" .word 1b replacement_insn .previous This is a dynamic shared object, so that .word cannot be resolved at build time, and thus cannot be used to execute the patches when the kernel initializes the images. Even trying to use label difference equations doesn't work in the above kind of scheme: 1: insn .section .whatever_patch, "ax" .word . - 1b replacement_insn .previous The assembler complains that it cannot resolve that computation. The issue is that this is contained in an executable section. Borrow the sequence used by x86 alternatives, which is: 1: insn .pushsection .whatever_patch, "a" .word . - 1b, . - 1f .popsection .pushsection .whatever_patch_replacements, "ax" 1: replacement_insn .previous This works, allows us to inline vread_tick() as much as we like, and can be used for arbitrary kinds of VDSO patching in the future. Also, reverse the condition for patching. Most systems are %stick based, so if we only patch on %tick systems the patching code will get little or no testing. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-17sparc: vDSO: Silence an uninitialized variable warningDan Carpenter
Smatch complains that "val" would be uninitialized if kstrtoul() fails. Fixes: 9a08862a5d2e ("vDSO for sparc") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-17sparc: Fix syscall fallback bugs in VDSO.David S. Miller
First, the trap number for 32-bit syscalls is 0x10. Also, only negate the return value when syscall error is indicated by the carry bit being set. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-07sparc: vdso: clean-up vdso MakefileMasahiro Yamada
arch/sparc/vdso/Makefile is a replica of arch/x86/entry/vdso/Makefile. Clean-up the Makefile in the same way as I did for x86: - Remove unnecessary export - Put the generated linker script to $(obj)/ instead of $(src)/ - Simplify cmd_vdso2c The corresponding x86 commits are: - 61615faf0a89 ("x86/build/vdso: Remove unnecessary export in Makefile") - 1742ed2088cc ("x86/build/vdso: Put generated linker scripts to $(obj)/") - c5fcdbf15523 ("x86/build/vdso: Simplify 'cmd_vdso2c'") Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-07kbuild: mark $(targets) as .SECONDARY and remove .PRECIOUS markersMasahiro Yamada
GNU Make automatically deletes intermediate files that are updated in a chain of pattern rules. Example 1) %.dtb.o <- %.dtb.S <- %.dtb <- %.dts Example 2) %.o <- %.c <- %.c_shipped A couple of makefiles mark such targets as .PRECIOUS to prevent Make from deleting them, but the correct way is to use .SECONDARY. .SECONDARY Prerequisites of this special target are treated as intermediate files but are never automatically deleted. .PRECIOUS When make is interrupted during execution, it may delete the target file it is updating if the file was modified since make started. If you mark the file as precious, make will never delete the file if interrupted. Both can avoid deletion of intermediate files, but the difference is the behavior when Make is interrupted; .SECONDARY deletes the target, but .PRECIOUS does not. The use of .PRECIOUS is relatively rare since we do not want to keep partially constructed (possibly corrupted) targets. Another difference is that .PRECIOUS works with pattern rules whereas .SECONDARY does not. .PRECIOUS: $(obj)/%.lex.c works, but .SECONDARY: $(obj)/%.lex.c has no effect. However, for the reason above, I do not want to use .PRECIOUS which could cause obscure build breakage. The targets specified as .SECONDARY must be explicit. $(targets) contains all targets that need to include .*.cmd files. So, the intermediates you want to keep are mostly in there. Therefore, mark $(targets) as .SECONDARY. It means primary targets are also marked as .SECONDARY, but I do not see any drawback for this. I replaced some .SECONDARY / .PRECIOUS markers with 'targets'. This will make Kbuild search for non-existing .*.cmd files, but this is not a noticeable performance issue. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Frank Rowand <frowand.list@gmail.com> Acked-by: Ingo Molnar <mingo@kernel.org>
2018-01-22sparc: vDSO: remove an extra tabDan Carpenter
This statement is indented one tab too far which is confusing and leads to a Smatch warning: arch/sparc/vdso/vma.c:254 arch_setup_additional_pages() warn: curly braces intended? Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Nagarathnam Muthusamy <nagarathnam.muthusamy@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-15vDSO for sparcNagarathnam Muthusamy
Following patch is based on work done by Nick Alcock on 64-bit vDSO for sparc in Oracle linux. I have extended it to include support for 32-bit vDSO for sparc on 64-bit kernel. vDSO for sparc is based on the X86 implementation. This patch provides vDSO support for both 64-bit and 32-bit programs on 64-bit kernel. vDSO will be disabled on 32-bit linux kernel on sparc. *) vclock_gettime.c contains all the vdso functions. Since data page is mapped before the vdso code page, the pointer to data page is got by subracting offset from an address in the vdso code page. The return address stored in %i7 is used for this purpose. *) During compilation, both 32-bit and 64-bit vdso images are compiled and are converted into raw bytes by vdso2c program to be ready for mapping into the process. 32-bit images are compiled only if CONFIG_COMPAT is enabled. vdso2c generates two files vdso-image-64.c and vdso-image-32.c which contains the respective vDSO image in C structure. *) During vdso initialization, required number of vdso pages are allocated and raw bytes are copied into the pages. *) During every exec, these pages are mapped into the process through arch_setup_additional_pages and the location of mapping is passed on to the process through aux vector AT_SYSINFO_EHDR which is used by glibc. *) A new update_vsyscall routine for sparc is added to keep the data page in vdso updated. *) As vDSO cannot contain dynamically relocatable references, a new version of cpu_relax is added for the use of vDSO. This change also requires a putback to glibc to use vDSO. For testing, programs planning to try vDSO can be compiled against the generated vdso(64/32).so in the source. Testing: ======== [root@localhost ~]# cat vdso_test.c int main() { struct timespec tv_start, tv_end; struct timeval tv_tmp; int i; int count = 1 * 1000 * 10000; long long diff; clock_gettime(0, &tv_start); for (i = 0; i < count; i++) gettimeofday(&tv_tmp, NULL); clock_gettime(0, &tv_end); diff = (long long)(tv_end.tv_sec - tv_start.tv_sec)*(1*1000*1000*1000); diff += (tv_end.tv_nsec - tv_start.tv_nsec); printf("Start sec: %d\n", tv_start.tv_sec); printf("End sec : %d\n", tv_end.tv_sec); printf("%d cycles in %lld ns = %f ns/cycle\n", count, diff, (double)diff / (double)count); return 0; } [root@localhost ~]# cc vdso_test.c -o t32_without_fix -m32 -lrt [root@localhost ~]# ./t32_without_fix Start sec: 1502396130 End sec : 1502396140 10000000 cycles in 9565148528 ns = 956.514853 ns/cycle [root@localhost ~]# cc vdso_test.c -o t32_with_fix -m32 ./vdso32.so.dbg [root@localhost ~]# ./t32_with_fix Start sec: 1502396168 End sec : 1502396169 10000000 cycles in 798141262 ns = 79.814126 ns/cycle [root@localhost ~]# cc vdso_test.c -o t64_without_fix -m64 -lrt [root@localhost ~]# ./t64_without_fix Start sec: 1502396208 End sec : 1502396218 10000000 cycles in 9846091800 ns = 984.609180 ns/cycle [root@localhost ~]# cc vdso_test.c -o t64_with_fix -m64 ./vdso64.so.dbg [root@localhost ~]# ./t64_with_fix Start sec: 1502396257 End sec : 1502396257 10000000 cycles in 380984048 ns = 38.098405 ns/cycle V1 to V2 Changes: ================= Added hot patching code to switch the read stick instruction to read tick instruction based on the hardware. V2 to V3 Changes: ================= Merged latest changes from sparc-next and moved the initialization of clocksource_tick.archdata.vclock_mode to time_init_early. Disabled queued spinlock and rwlock configuration when simulating 32-bit config to compile 32-bit VDSO. V3 to V4 Changes: ================= Hardcoded the page size as 8192 in linker script for both 64-bit and 32-bit binaries. Removed unused variables in vdso2c.h. Added -mv8plus flag to Makefile to prevent the generation of relocation entries for __lshrdi3 in 32-bit vdso binary. Signed-off-by: Nick Alcock <nick.alcock@oracle.com> Signed-off-by: Nagarathnam Muthusamy <nagarathnam.muthusamy@oracle.com> Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>