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2022-04-21selftest/vm: verify mmap addr in mremap_testSidhartha Kumar
Avoid calling mmap with requested addresses that are less than the system's mmap_min_addr. When run as root, mmap returns EACCES when trying to map addresses < mmap_min_addr. This is not one of the error codes for the condition to retry the mmap in the test. Rather than arbitrarily retrying on EACCES, don't attempt an mmap until addr > vm.mmap_min_addr. Add a munmap call after an alignment check as the mappings are retained after the retry and can reach the vm.max_map_count sysctl. Link: https://lkml.kernel.org/r/20220420215721.4868-1-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-04-21kvm: selftests: introduce and use more page size-related constantsPaolo Bonzini
Clean up code that was hardcoding masks for various fields, now that the masks are included in processor.h. For more cleanup, define PAGE_SIZE and PAGE_MASK just like in Linux. PAGE_SIZE in particular was defined by several tests. Suggested-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-21kvm: selftests: do not use bitfields larger than 32-bits for PTEsPaolo Bonzini
Red Hat's QE team reported test failure on access_tracking_perf_test: Testing guest mode: PA-bits:ANY, VA-bits:48, 4K pages guest physical test memory offset: 0x3fffbffff000 Populating memory : 0.684014577s Writing to populated memory : 0.006230175s Reading from populated memory : 0.004557805s ==== Test Assertion Failure ==== lib/kvm_util.c:1411: false pid=125806 tid=125809 errno=4 - Interrupted system call 1 0x0000000000402f7c: addr_gpa2hva at kvm_util.c:1411 2 (inlined by) addr_gpa2hva at kvm_util.c:1405 3 0x0000000000401f52: lookup_pfn at access_tracking_perf_test.c:98 4 (inlined by) mark_vcpu_memory_idle at access_tracking_perf_test.c:152 5 (inlined by) vcpu_thread_main at access_tracking_perf_test.c:232 6 0x00007fefe9ff81ce: ?? ??:0 7 0x00007fefe9c64d82: ?? ??:0 No vm physical memory at 0xffbffff000 I can easily reproduce it with a Intel(R) Xeon(R) CPU E5-2630 with 46 bits PA. It turns out that the address translation for clearing idle page tracking returned a wrong result; addr_gva2gpa()'s last step, which is based on "pte[index[0]].pfn", did the calculation with 40 bits length and the high 12 bits got truncated. In above case the GPA address to be returned should be 0x3fffbffff000 for GVA 0xc0000000, but it got truncated into 0xffbffff000 and the subsequent gpa2hva lookup failed. The width of operations on bit fields greater than 32-bit is implementation defined, and differs between GCC (which uses the bitfield precision) and clang (which uses 64-bit arithmetic), so this is a potential minefield. Remove the bit fields and using manual masking instead. Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2075036 Reported-by: Nana Liu <nanliu@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Tested-by: Peter Xu <peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-21Merge tag 'net-5.18-rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Paolo Abeni: "Including fixes from xfrm and can. Current release - regressions: - rxrpc: restore removed timer deletion Current release - new code bugs: - gre: fix device lookup for l3mdev use-case - xfrm: fix egress device lookup for l3mdev use-case Previous releases - regressions: - sched: cls_u32: fix netns refcount changes in u32_change() - smc: fix sock leak when release after smc_shutdown() - xfrm: limit skb_page_frag_refill use to a single page - eth: atlantic: invert deep par in pm functions, preventing null derefs - eth: stmmac: use readl_poll_timeout_atomic() in atomic state Previous releases - always broken: - gre: fix skb_under_panic on xmit - openvswitch: fix OOB access in reserve_sfa_size() - dsa: hellcreek: calculate checksums in tagger - eth: ice: fix crash in switchdev mode - eth: igc: - fix infinite loop in release_swfw_sync - fix scheduling while atomic" * tag 'net-5.18-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (37 commits) drivers: net: hippi: Fix deadlock in rr_close() selftests: mlxsw: vxlan_flooding_ipv6: Prevent flooding of unwanted packets selftests: mlxsw: vxlan_flooding: Prevent flooding of unwanted packets nfc: MAINTAINERS: add Bug entry net: stmmac: Use readl_poll_timeout_atomic() in atomic state doc/ip-sysctl: add bc_forwarding netlink: reset network and mac headers in netlink_dump() net: mscc: ocelot: fix broken IP multicast flooding net: dsa: hellcreek: Calculate checksums in tagger net: atlantic: invert deep par in pm functions, preventing null derefs can: isotp: stop timeout monitoring when no first frame was sent bonding: do not discard lowest hash bit for non layer3+4 hashing net: lan966x: Make sure to release ptp interrupt ipv6: make ip6_rt_gc_expire an atomic_t net: Handle l3mdev in ip_tunnel_init_flow l3mdev: l3mdev_master_upper_ifindex_by_index_rcu should be using netdev_master_upper_dev_get_rcu net/sched: cls_u32: fix possible leak in u32_init_knode() net/sched: cls_u32: fix netns refcount changes in u32_change() powerpc: Update MAINTAINERS for ibmvnic and VAS net: restore alpha order to Ethernet devices in config ...
2022-04-21KVM: selftests: Silence compiler warning in the kvm_page_table_testThomas Huth
When compiling kvm_page_table_test.c, I get this compiler warning with gcc 11.2: kvm_page_table_test.c: In function 'pre_init_before_test': ../../../../tools/include/linux/kernel.h:44:24: warning: comparison of distinct pointer types lacks a cast 44 | (void) (&_max1 == &_max2); \ | ^~ kvm_page_table_test.c:281:21: note: in expansion of macro 'max' 281 | alignment = max(0x100000, alignment); | ^~~ Fix it by adjusting the type of the absolute value. Signed-off-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-Id: <20220414103031.565037-1-thuth@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-21libbpf: Remove redundant non-null checks on obj_elfGaosheng Cui
Obj_elf is already non-null checked at the function entry, so remove redundant non-null checks on obj_elf. Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220421031803.2283974-1-cuigaosheng1@huawei.com
2022-04-21selftests/bpf: Fix map tests errno checksArtem Savkov
Switching to libbpf 1.0 API broke test_lpm_map and test_lru_map as error reporting changed. Instead of setting errno and returning -1 bpf calls now return -Exxx directly. Drop errno checks and look at return code directly. Fixes: b858ba8c52b6 ("selftests/bpf: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK") Signed-off-by: Artem Savkov <asavkov@redhat.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Yafang Shao <laoar.shao@gmail.com> Link: https://lore.kernel.org/bpf/20220421094320.1563570-1-asavkov@redhat.com
2022-04-21selftests/bpf: Fix prog_tests uprobe_autoattach compilation errorArtem Savkov
I am getting the following compilation error for prog_tests/uprobe_autoattach.c: tools/testing/selftests/bpf/prog_tests/uprobe_autoattach.c: In function ‘test_uprobe_autoattach’: ./test_progs.h:209:26: error: pointer ‘mem’ may be used after ‘free’ [-Werror=use-after-free] The value of mem is now used in one of the asserts, which is why it may be confusing compilers. However, it is not dereferenced. Silence this by moving free(mem) after the assert block. Fixes: 1717e248014c ("selftests/bpf: Uprobe tests should verify param/return values") Signed-off-by: Artem Savkov <asavkov@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20220421132317.1583867-1-asavkov@redhat.com
2022-04-21selftests/bpf: Fix attach tests retcode checksArtem Savkov
Switching to libbpf 1.0 API broke test_sock and test_sysctl as they check for return of bpf_prog_attach to be exactly -1. Switch the check to '< 0' instead. Fixes: b858ba8c52b6 ("selftests/bpf: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK") Signed-off-by: Artem Savkov <asavkov@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Yafang Shao <laoar.shao@gmail.com> Link: https://lore.kernel.org/bpf/20220421130104.1582053-1-asavkov@redhat.com
2022-04-21libbpf: Add documentation to API functionsGrant Seltzer
This adds documentation for the following API functions: - bpf_program__set_expected_attach_type() - bpf_program__set_type() - bpf_program__set_attach_target() - bpf_program__attach() - bpf_program__pin() - bpf_program__unpin() Signed-off-by: Grant Seltzer <grantseltzer@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20220420161226.86803-3-grantseltzer@gmail.com
2022-04-21libbpf: Update API functions usage to check errorGrant Seltzer
This updates usage of the following API functions within libbpf so their newly added error return is checked: - bpf_program__set_expected_attach_type() - bpf_program__set_type() Signed-off-by: Grant Seltzer <grantseltzer@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20220420161226.86803-2-grantseltzer@gmail.com
2022-04-21libbpf: Add error returns to two API functionsGrant Seltzer
This adds an error return to the following API functions: - bpf_program__set_expected_attach_type() - bpf_program__set_type() In both cases, the error occurs when the BPF object has already been loaded when the function is called. In this case -EBUSY is returned. Signed-off-by: Grant Seltzer <grantseltzer@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20220420161226.86803-1-grantseltzer@gmail.com
2022-04-20tools/nolibc/string: Implement `strdup()` and `strndup()`Ammar Faizi
These functions are currently only available on architectures that have my_syscall6() macro implemented. Since these functions use malloc(), malloc() uses mmap(), mmap() depends on my_syscall6() macro. On architectures that don't support my_syscall6(), these function will always return NULL with errno set to ENOSYS. Acked-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/string: Implement `strnlen()`Ammar Faizi
size_t strnlen(const char *str, size_t maxlen); The strnlen() function returns the number of bytes in the string pointed to by sstr, excluding the terminating null byte ('\0'), but at most maxlen. In doing this, strnlen() looks only at the first maxlen characters in the string pointed to by str and never beyond str[maxlen-1]. The first use case of this function is for determining the memory allocation size in the strndup() function. Link: https://lore.kernel.org/lkml/CAOG64qMpEMh+EkOfjNdAoueC+uQyT2Uv3689_sOr37-JxdJf4g@mail.gmail.com Suggested-by: Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org> Acked-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/stdlib: Implement `malloc()`, `calloc()`, `realloc()` and `free()`Ammar Faizi
Implement basic dynamic allocator functions. These functions are currently only available on architectures that have nolibc mmap() syscall implemented. These are not a super-fast memory allocator, but at least they can satisfy basic needs for having heap without libc. Cc: David Laight <David.Laight@ACULAB.COM> Acked-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/types: Implement `offsetof()` and `container_of()` macroAmmar Faizi
Implement `offsetof()` and `container_of()` macro. The first use case of these macros is for `malloc()`, `realloc()` and `free()`. Acked-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/sys: Implement `mmap()` and `munmap()`Ammar Faizi
Implement mmap() and munmap(). Currently, they are only available for architecures that have my_syscall6 macro. For architectures that don't have, this function will return -1 with errno set to ENOSYS (Function not implemented). This has been tested on x86 and i386. Notes for i386: 1) The common mmap() syscall implementation uses __NR_mmap2 instead of __NR_mmap. 2) The offset must be shifted-right by 12-bit. Acked-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc: i386: Implement syscall with 6 argumentsAmmar Faizi
On i386, the 6th argument of syscall goes in %ebp. However, both Clang and GCC cannot use %ebp in the clobber list and in the "r" constraint without using -fomit-frame-pointer. To make it always available for any kind of compilation, the below workaround is implemented. 1) Push the 6-th argument. 2) Push %ebp. 3) Load the 6-th argument from 4(%esp) to %ebp. 4) Do the syscall (int $0x80). 5) Pop %ebp (restore the old value of %ebp). 6) Add %esp by 4 (undo the stack pointer). Cc: x86@kernel.org Cc: llvm@lists.linux.dev Link: https://lore.kernel.org/lkml/2e335ac54db44f1d8496583d97f9dab0@AcuMS.aculab.com Suggested-by: David Laight <David.Laight@ACULAB.COM> Acked-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc: Remove .global _start from the entry point codeAmmar Faizi
Building with clang yields the following error: ``` <inline asm>:3:1: error: _start changed binding to STB_GLOBAL .global _start ^ 1 error generated. ``` Make sure only specify one between `.global _start` and `.weak _start`. Remove `.global _start`. Cc: llvm@lists.linux.dev Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Acked-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc: Replace `asm` with `__asm__`Ammar Faizi
Replace `asm` with `__asm__` to support compilation with -std flag. Using `asm` with -std flag makes GCC think `asm()` is a function call instead of an inline assembly. GCC doc says: For the C language, the `asm` keyword is a GNU extension. When writing C code that can be compiled with `-ansi` and the `-std` options that select C dialects without GNU extensions, use `__asm__` instead of `asm`. Link: https://gcc.gnu.org/onlinedocs/gcc/Basic-Asm.html Reported-by: Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org> Acked-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc: x86-64: Update System V ABI document linkAmmar Faizi
The old link no longer works, update it. Acked-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/stdlib: only reference the external environ when inlinedWilly Tarreau
When building with gcc at -O0 we're seeing link errors due to the "environ" variable being referenced by getenv(). The problem is that at -O0 gcc will not inline getenv() and will not drop the external reference. One solution would be to locally declare the variable as weak, but then it would appear in all programs even those not using it, and would be confusing to users of getenv() who would forget to set environ to envp. An alternate approach used in this patch consists in always inlining the outer part of getenv() that references this extern so that it's always dropped when not used. The biggest part of the function was now moved to a new function called _getenv() that's still not inlined by default. Reported-by: Ammar Faizi <ammarfaizi2@gnuweeb.org> Signed-off-by: Willy Tarreau <w@1wt.eu> Tested-by: Ammar Faizi <ammarfaizi2@gnuweeb.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/string: do not use __builtin_strlen() at -O0Willy Tarreau
clang wants to use strlen() for __builtin_strlen() at -O0. We don't really care about -O0 but it at least ought to build, so let's make sure we don't choke on this, by dropping the optimizationn for constant strings in this case. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc: add the nolibc subdir to the common MakefileWilly Tarreau
The Makefile in tools/ is used to forward options to the makefiles in the various subdirs. Let's add nolibc there so that it becomes possible to make tools/nolibc_headers_standalone from the main tree to simply create a completely usable sysroot. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc: add a makefile to install headersWilly Tarreau
This provides a target "headers_standalone" which installs the nolibc's arch-specific headers with "arch.h" taken from the current arch (or a concatenation of both i386 and x86_64 for arch=x86), then installs kernel headers. This creates a convenient sysroot which is directly usable by a bare-metal compiler to create any executable. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/types: add poll() and waitpid() flag definitionsWilly Tarreau
- POLLIN etc were missing, so poll() could only be used with timeouts. - WNOHANG was not defined and is convenient to check if a child is still running Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/sys: add syscall definition for getppid()Willy Tarreau
This is essentially for completeness as it's not the most often used in regtests. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/string: add strcmp() and strncmp()Willy Tarreau
We need these functions all the time, including when checking environment variables and parsing command-line arguments. These implementations were optimized to show optimal code size on a wide range of compilers (22 bytes return included for strcmp(), 33 for strncmp()). Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/stdio: add support for '%p' to vfprintf()Willy Tarreau
%p remains quite useful in test code, and the code path can easily be merged with the existing "%x" thus only adds ~50 bytes, thus let's add it. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/stdlib: add a simple getenv() implementationWilly Tarreau
This implementation relies on an extern definition of the environ variable, that the caller must declare and initialize from envp. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/stdio: make printf(%s) accept NULLWilly Tarreau
It's often convenient to support this, especially in test programs where a NULL may correspond to an allocation error or a non-existing value. Let's make printf("%s") support being passed a NULL. In this case it prints "(null)" like glibc's printf(). Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/stdlib: implement abort()Willy Tarreau
libgcc uses it for certain divide functions, so it must be exported. Like for memset() we do that in its own section so that the linker can strip it when not needed. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc: also mention how to build by just setting the include pathWilly Tarreau
Now that a few basic include files are provided, some simple portable programs may build, which will save them from having to surround their includes with #ifndef NOLIBC. This patch mentions how to proceed, and enumerates the list of files that are covered. A comprehensive list of required include files is available here: https://en.cppreference.com/w/c/header Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/time: create time.h with time()Willy Tarreau
The time() syscall is used by a few simple applications, and is trivial to implement based on gettimeofday() that we already have. Let's create the file to ease porting and provide the function. It never returns any error, though it may segfault in case of invalid pointer, like other implementations relying on gettimeofday(). Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/signal: move raise() to signal.hWilly Tarreau
This function is normally found in signal.h, and providing the file eases porting of existing programs. Let's move it there. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/unistd: add usleep()Willy Tarreau
This call is trivial to implement based on select() to complete sleep() and msleep(), let's add it. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/unistd: extract msleep(), sleep(), tcsetpgrp() to unistd.hWilly Tarreau
These functions are normally provided by unistd.h. For ease of porting, let's create the file and move them there. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/errno: extract errno.h from sys.hWilly Tarreau
This allows us to provide a minimal errno.h to ease porting applications that use it. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/string: export memset() and memmove()Willy Tarreau
"clang -Os" and "gcc -Ofast" without -ffreestanding may ignore memset() and memmove(), hoping to provide their builtin equivalents, and finally not find them. Thus we must export these functions for these rare cases. Note that as they're set in their own sections, they will be eliminated by the linker if not used. In addition, they do not prevent gcc from identifying them and replacing them with the shorter "rep movsb" or "rep stosb" when relevant. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/types: define PATH_MAX and MAXPATHLENWilly Tarreau
These ones are often used and commonly set by applications to fallback values. Let's fix them both to agree on PATH_MAX=4096 by default, as is already present in linux/limits.h. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/arch: mark the _start symbol as weakWilly Tarreau
By doing so we can link together multiple C files that have been compiled with nolibc and which each have a _start symbol. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc: move exported functions to their own sectionWilly Tarreau
Some functions like raise() and memcpy() are permanently exported because they're needed by libgcc on certain platforms. However most of the time they are not needed and needlessly take space. Let's move them to their own sub-section, called .text.nolibc_<function>. This allows ld to get rid of them if unused when passed --gc-sections. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/string: add tiny versions of strncat() and strlcat()Willy Tarreau
While these functions are often dangerous, forcing the user to work around their absence is often much worse. Let's provide small versions of each of them. The respective sizes in bytes on a few architectures are: strncat(): x86:0x33 mips:0x68 arm:0x3c strlcat(): x86:0x25 mips:0x4c arm:0x2c The two are quite different, and strncat() is even different from strncpy() in that it limits the amount of data it copies and will always terminate the output by one zero, while strlcat() will always limit the total output to the specified size and will put a zero if possible. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/string: add strncpy() and strlcpy()Willy Tarreau
These are minimal variants. strncpy() always fills the destination for <size> chars, while strlcpy() copies no more than <size> including the zero and returns the source's length. The respective sizes on various archs are: strncpy(): x86:0x1f mips:0x30 arm:0x20 strlcpy(): x86:0x17 mips:0x34 arm:0x1a Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/string: slightly simplify memmove()Willy Tarreau
The direction test inside the loop was not always completely optimized, resulting in a larger than necessary function. This change adds a direction variable that is set out of the loop. Now the function is down to 48 bytes on x86, 32 on ARM and 68 on mips. It's worth noting that other approaches were attempted (including relying on the up and down functions) but they were only slightly beneficial on x86 and cost more on others. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/string: use unidirectional variants for memcpy()Willy Tarreau
Till now memcpy() relies on memmove(), but it's always included for libgcc, so we have a larger than needed function. Let's implement two unidirectional variants to copy from bottom to top and from top to bottom, and use the former for memcpy(). The variants are optimized to be compact, and at the same time the compiler is sometimes able to detect the loop and to replace it with a "rep movsb". The new function is 24 bytes instead of 52 on x86_64. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/sys: make getpgrp(), getpid(), gettid() not set errnoWilly Tarreau
These syscalls never fail so there is no need to extract and set errno for them. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/stdlib: make raise() use the lower level syscalls onlyWilly Tarreau
raise() doesn't set errno, so there's no point calling kill(), better call sys_kill(), which also reduces the function's size. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/stdlib: avoid a 64-bit shift in u64toh_r()Willy Tarreau
The build of printf() on mips requires libgcc for functions __ashldi3 and __lshrdi3 due to 64-bit shifts when scanning the input number. These are not really needed in fact since we scan the number 4 bits at a time. Let's arrange the loop to perform two 32-bit shifts instead on 32-bit platforms. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/sys: make open() take a vararg on the 3rd argumentWilly Tarreau
Let's pass a vararg to open() so that it remains compatible with existing code. The arg is only dereferenced when flags contain O_CREAT. The function is generally not inlined anymore, causing an extra call (total 16 extra bytes) but it's still optimized for constant propagation, limiting the excess to no more than 16 bytes in practice when open() is called without O_CREAT, and ~40 with O_CREAT, which remains reasonable. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>