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2022-04-22objtool: Reorganize cmdline optionsJosh Poimboeuf7-62/+84
Split the existing options into two groups: actions, which actually do something; and options, which modify the actions in some way. Also there's no need to have short flags for all the non-action options. Reserve short flags for the more important actions. While at it: - change a few of the short flags to be more intuitive - make option descriptions more consistently descriptive - sort options in the source like they are when printed - move options to a global struct Signed-off-by: Josh Poimboeuf <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Link: https://lkml.kernel.org/r/9dcaa752f83aca24b1b21f0b0eeb28a0c181c0b0.1650300597.git.jpoimboe@redhat.com
2022-04-22libsubcmd: Fix OPTION_GROUP sortingJosh Poimboeuf1-3/+14
The OPTION_GROUP option type is a way of grouping certain options together in the printed usage text. It happens to be completely broken, thanks to the fact that the subcmd option sorting just sorts everything, without regard for grouping. Luckily, nobody uses this option anyway, though that will change shortly. Fix it by sorting each group individually. Signed-off-by: Josh Poimboeuf <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Link: https://lkml.kernel.org/r/e167ea3a11e2a9800eb062c1fd0f13e9cd05140c.1650300597.git.jpoimboe@redhat.com
2022-04-22Merge branch 'tip/x86/urgent'Peter Zijlstra1-8/+5
Merge the x86/urgent objtool/IBT changes as a base Signed-off-by: Peter Zijlstra <[email protected]>
2022-04-22objtool: Fix code relocs vs weak symbolsPeter Zijlstra1-22/+165
Occasionally objtool driven code patching (think .static_call_sites .retpoline_sites etc..) goes sideways and it tries to patch an instruction that doesn't match. Much head-scatching and cursing later the problem is as outlined below and affects every section that objtool generates for us, very much including the ORC data. The below uses .static_call_sites because it's convenient for demonstration purposes, but as mentioned the ORC sections, .retpoline_sites and __mount_loc are all similarly affected. Consider: foo-weak.c: extern void __SCT__foo(void); __attribute__((weak)) void foo(void) { return __SCT__foo(); } foo.c: extern void __SCT__foo(void); extern void my_foo(void); void foo(void) { my_foo(); return __SCT__foo(); } These generate the obvious code (gcc -O2 -fcf-protection=none -fno-asynchronous-unwind-tables -c foo*.c): foo-weak.o: 0000000000000000 <foo>: 0: e9 00 00 00 00 jmpq 5 <foo+0x5> 1: R_X86_64_PLT32 __SCT__foo-0x4 foo.o: 0000000000000000 <foo>: 0: 48 83 ec 08 sub $0x8,%rsp 4: e8 00 00 00 00 callq 9 <foo+0x9> 5: R_X86_64_PLT32 my_foo-0x4 9: 48 83 c4 08 add $0x8,%rsp d: e9 00 00 00 00 jmpq 12 <foo+0x12> e: R_X86_64_PLT32 __SCT__foo-0x4 Now, when we link these two files together, you get something like (ld -r -o foos.o foo-weak.o foo.o): foos.o: 0000000000000000 <foo-0x10>: 0: e9 00 00 00 00 jmpq 5 <foo-0xb> 1: R_X86_64_PLT32 __SCT__foo-0x4 5: 66 2e 0f 1f 84 00 00 00 00 00 nopw %cs:0x0(%rax,%rax,1) f: 90 nop 0000000000000010 <foo>: 10: 48 83 ec 08 sub $0x8,%rsp 14: e8 00 00 00 00 callq 19 <foo+0x9> 15: R_X86_64_PLT32 my_foo-0x4 19: 48 83 c4 08 add $0x8,%rsp 1d: e9 00 00 00 00 jmpq 22 <foo+0x12> 1e: R_X86_64_PLT32 __SCT__foo-0x4 Noting that ld preserves the weak function text, but strips the symbol off of it (hence objdump doing that funny negative offset thing). This does lead to 'interesting' unused code issues with objtool when ran on linked objects, but that seems to be working (fingers crossed). So far so good.. Now lets consider the objtool static_call output section (readelf output, old binutils): foo-weak.o: Relocation section '.rela.static_call_sites' at offset 0x2c8 contains 1 entry: Offset Info Type Symbol's Value Symbol's Name + Addend 0000000000000000 0000000200000002 R_X86_64_PC32 0000000000000000 .text + 0 0000000000000004 0000000d00000002 R_X86_64_PC32 0000000000000000 __SCT__foo + 1 foo.o: Relocation section '.rela.static_call_sites' at offset 0x310 contains 2 entries: Offset Info Type Symbol's Value Symbol's Name + Addend 0000000000000000 0000000200000002 R_X86_64_PC32 0000000000000000 .text + d 0000000000000004 0000000d00000002 R_X86_64_PC32 0000000000000000 __SCT__foo + 1 foos.o: Relocation section '.rela.static_call_sites' at offset 0x430 contains 4 entries: Offset Info Type Symbol's Value Symbol's Name + Addend 0000000000000000 0000000100000002 R_X86_64_PC32 0000000000000000 .text + 0 0000000000000004 0000000d00000002 R_X86_64_PC32 0000000000000000 __SCT__foo + 1 0000000000000008 0000000100000002 R_X86_64_PC32 0000000000000000 .text + 1d 000000000000000c 0000000d00000002 R_X86_64_PC32 0000000000000000 __SCT__foo + 1 So we have two patch sites, one in the dead code of the weak foo and one in the real foo. All is well. *HOWEVER*, when the toolchain strips unused section symbols it generates things like this (using new enough binutils): foo-weak.o: Relocation section '.rela.static_call_sites' at offset 0x2c8 contains 1 entry: Offset Info Type Symbol's Value Symbol's Name + Addend 0000000000000000 0000000200000002 R_X86_64_PC32 0000000000000000 foo + 0 0000000000000004 0000000d00000002 R_X86_64_PC32 0000000000000000 __SCT__foo + 1 foo.o: Relocation section '.rela.static_call_sites' at offset 0x310 contains 2 entries: Offset Info Type Symbol's Value Symbol's Name + Addend 0000000000000000 0000000200000002 R_X86_64_PC32 0000000000000000 foo + d 0000000000000004 0000000d00000002 R_X86_64_PC32 0000000000000000 __SCT__foo + 1 foos.o: Relocation section '.rela.static_call_sites' at offset 0x430 contains 4 entries: Offset Info Type Symbol's Value Symbol's Name + Addend 0000000000000000 0000000100000002 R_X86_64_PC32 0000000000000000 foo + 0 0000000000000004 0000000d00000002 R_X86_64_PC32 0000000000000000 __SCT__foo + 1 0000000000000008 0000000100000002 R_X86_64_PC32 0000000000000000 foo + d 000000000000000c 0000000d00000002 R_X86_64_PC32 0000000000000000 __SCT__foo + 1 And now we can see how that foos.o .static_call_sites goes side-ways, we now have _two_ patch sites in foo. One for the weak symbol at foo+0 (which is no longer a static_call site!) and one at foo+d which is in fact the right location. This seems to happen when objtool cannot find a section symbol, in which case it falls back to any other symbol to key off of, however in this case that goes terribly wrong! As such, teach objtool to create a section symbol when there isn't one. Fixes: 44f6a7c0755d ("objtool: Fix seg fault with Clang non-section symbols") Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Acked-by: Josh Poimboeuf <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2022-04-22objtool: Fix type of reloc::addendPeter Zijlstra3-7/+7
Elf{32,64}_Rela::r_addend is of type: Elf{32,64}_Sword, that means that our reloc::addend needs to be long or face tuncation issues when we do elf_rebuild_reloc_section(): - 107: 48 b8 00 00 00 00 00 00 00 00 movabs $0x0,%rax 109: R_X86_64_64 level4_kernel_pgt+0x80000067 + 107: 48 b8 00 00 00 00 00 00 00 00 movabs $0x0,%rax 109: R_X86_64_64 level4_kernel_pgt-0x7fffff99 Fixes: 627fce14809b ("objtool: Add ORC unwind table generation") Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Acked-by: Josh Poimboeuf <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2022-04-21selftest/vm: add skip support to mremap_testSidhartha Kumar1-3/+8
Allow the mremap test to be skipped due to errors such as failing to parse the mmap_min_addr sysctl. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Sidhartha Kumar <[email protected]> Reviewed-by: Shuah Khan <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2022-04-21selftest/vm: support xfail in mremap_testSidhartha Kumar1-1/+1
Use ksft_test_result_xfail for the tests which are expected to fail. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Sidhartha Kumar <[email protected]> Reviewed-by: Shuah Khan <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2022-04-21selftest/vm: verify remap destination address in mremap_testSidhartha Kumar1-3/+39
Because mremap does not have a MAP_FIXED_NOREPLACE flag, it can destroy existing mappings. This causes a segfault when regions such as text are remapped and the permissions are changed. Verify the requested mremap destination address does not overlap any existing mappings by using mmap's MAP_FIXED_NOREPLACE flag. Keep incrementing the destination address until a valid mapping is found or fail the current test once the max address is reached. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Sidhartha Kumar <[email protected]> Reviewed-by: Shuah Khan <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2022-04-21selftest/vm: verify mmap addr in mremap_testSidhartha Kumar1-1/+40
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/[email protected] Signed-off-by: Sidhartha Kumar <[email protected]> Reviewed-by: Shuah Khan <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2022-04-21kvm: selftests: introduce and use more page size-related constantsPaolo Bonzini8-13/+8
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 <[email protected]> Reviewed-by: Peter Xu <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2022-04-21kvm: selftests: do not use bitfields larger than 32-bits for PTEsPaolo Bonzini2-115/+92
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 <[email protected]> Reviewed-by: Peter Xu <[email protected]> Tested-by: Peter Xu <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2022-04-21Merge tag 'net-5.18-rc4' of ↵Linus Torvalds2-0/+34
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 Huth1-1/+1
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 <[email protected]> Reviewed-by: Claudio Imbrenda <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2022-04-20tools/nolibc/string: Implement `strdup()` and `strndup()`Ammar Faizi1-0/+32
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 <[email protected]> Signed-off-by: Ammar Faizi <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc/string: Implement `strnlen()`Ammar Faizi1-0/+9
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 <[email protected]> Acked-by: Willy Tarreau <[email protected]> Signed-off-by: Ammar Faizi <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc/stdlib: Implement `malloc()`, `calloc()`, `realloc()` and `free()`Ammar Faizi1-0/+81
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 <[email protected]> Acked-by: Willy Tarreau <[email protected]> Signed-off-by: Ammar Faizi <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc/types: Implement `offsetof()` and `container_of()` macroAmmar Faizi1-0/+11
Implement `offsetof()` and `container_of()` macro. The first use case of these macros is for `malloc()`, `realloc()` and `free()`. Acked-by: Willy Tarreau <[email protected]> Signed-off-by: Ammar Faizi <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc/sys: Implement `mmap()` and `munmap()`Ammar Faizi1-0/+62
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 <[email protected]> Signed-off-by: Ammar Faizi <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc: i386: Implement syscall with 6 argumentsAmmar Faizi1-0/+23
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: [email protected] Cc: [email protected] Link: https://lore.kernel.org/lkml/[email protected] Suggested-by: David Laight <[email protected]> Acked-by: Willy Tarreau <[email protected]> Signed-off-by: Ammar Faizi <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc: Remove .global _start from the entry point codeAmmar Faizi6-6/+0
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: [email protected] Reviewed-by: Nick Desaulniers <[email protected]> Acked-by: Willy Tarreau <[email protected]> Signed-off-by: Ammar Faizi <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc: Replace `asm` with `__asm__`Ammar Faizi6-198/+198
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 <[email protected]> Acked-by: Willy Tarreau <[email protected]> Signed-off-by: Ammar Faizi <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc: x86-64: Update System V ABI document linkAmmar Faizi1-1/+1
The old link no longer works, update it. Acked-by: Willy Tarreau <[email protected]> Signed-off-by: Ammar Faizi <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc/stdlib: only reference the external environ when inlinedWilly Tarreau1-7/+15
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 <[email protected]> Signed-off-by: Willy Tarreau <[email protected]> Tested-by: Ammar Faizi <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc/string: do not use __builtin_strlen() at -O0Willy Tarreau1-1/+10
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 <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc: add the nolibc subdir to the common MakefileWilly Tarreau1-0/+4
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 <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc: add a makefile to install headersWilly Tarreau1-0/+42
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 <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc/types: add poll() and waitpid() flag definitionsWilly Tarreau1-0/+10
- 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 <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc/sys: add syscall definition for getppid()Willy Tarreau1-0/+17
This is essentially for completeness as it's not the most often used in regtests. Signed-off-by: Willy Tarreau <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc/string: add strcmp() and strncmp()Willy Tarreau1-0/+23
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 <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc/stdio: add support for '%p' to vfprintf()Willy Tarreau1-11/+19
%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 <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc/stdlib: add a simple getenv() implementationWilly Tarreau1-0/+23
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 <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc/stdio: make printf(%s) accept NULLWilly Tarreau1-0/+2
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 <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc/stdlib: implement abort()Willy Tarreau1-0/+8
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 <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc: also mention how to build by just setting the include pathWilly Tarreau1-10/+20
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 <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc/time: create time.h with time()Willy Tarreau2-0/+29
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 <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc/signal: move raise() to signal.hWilly Tarreau3-7/+23
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 <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc/unistd: add usleep()Willy Tarreau1-0/+8
This call is trivial to implement based on select() to complete sleep() and msleep(), let's add it. Signed-off-by: Willy Tarreau <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc/unistd: extract msleep(), sleep(), tcsetpgrp() to unistd.hWilly Tarreau3-30/+47
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 <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc/errno: extract errno.h from sys.hWilly Tarreau3-16/+29
This allows us to provide a minimal errno.h to ease porting applications that use it. Signed-off-by: Willy Tarreau <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc/string: export memset() and memmove()Willy Tarreau1-2/+8
"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 <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc/types: define PATH_MAX and MAXPATHLENWilly Tarreau1-0/+11
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 <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc/arch: mark the _start symbol as weakWilly Tarreau6-0/+6
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 <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc: move exported functions to their own sectionWilly Tarreau2-2/+2
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 <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc/string: add tiny versions of strncat() and strlcat()Willy Tarreau1-0/+41
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 <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc/string: add strncpy() and strlcpy()Willy Tarreau1-0/+28
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 <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc/string: slightly simplify memmove()Willy Tarreau1-6/+14
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 <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc/string: use unidirectional variants for memcpy()Willy Tarreau1-1/+23
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 <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc/sys: make getpgrp(), getpid(), gettid() not set errnoWilly Tarreau1-21/+3
These syscalls never fail so there is no need to extract and set errno for them. Signed-off-by: Willy Tarreau <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc/stdlib: make raise() use the lower level syscalls onlyWilly Tarreau1-1/+1
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 <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-04-20tools/nolibc/stdlib: avoid a 64-bit shift in u64toh_r()Willy Tarreau1-6/+10
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 <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>