- 20 4月, 2018 7 次提交
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由 Rich Felker 提交于
commit 618b18c7 removed the previous detection and hardening since it was incorrect. commit 72141795 already handled all that remained for hardening the static-linked case. in the dynamic-linked case, have the dynamic linker check whether malloc was replaced and make that information available. with these changes, the properties documented in commit c9f415d7 are restored: if calloc is not provided, it will behave as malloc+memset, and any of the memalign-family functions not provided will fail with ENOMEM.
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由 Rich Felker 提交于
this change serves multiple purposes: 1. it ensures that static linking of memalign-family functions will pull in the system malloc implementation, thereby causing link errors if an attempt is made to link the system memalign functions with a replacement malloc (incomplete allocator replacement). 2. it eliminates calls to free that are unpaired with allocations, which are confusing when setting breakpoints or tracing execution. as a bonus, making __bin_chunk external may discourage aggressive and unnecessary inlining of it.
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由 Rich Felker 提交于
the generated code should be mostly unchanged, except for explicit use of C_INUSE in place of copying the low bits from existing chunk headers/footers. these changes also remove mild UB due to dubious arithmetic on pointers into imaginary size_t[] arrays.
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由 Rich Felker 提交于
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由 Rich Felker 提交于
commit c9f415d7 included checks to make calloc fallback to memset if used with a replaced malloc that didn't also replace calloc, and the memalign family fail if free has been replaced. however, the checks gave false positives for replacement whenever malloc or free resolved to a PLT entry in the main program. for now, disable the checks so as not to leave libc in a broken state. this means that the properties documented in the above commit are no longer satisfied; failure to replace calloc and the memalign family along with malloc is unsafe if they are ever called. the calloc checks were correct but useless for static linking. in both cases (simple or full malloc), calloc and malloc are in a source file together, so replacement of one but not the other would give linking errors. the memalign-family check was useful for static linking, but broken for dynamic as described above, and can be replaced with a better link-time check.
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由 Will Dietz 提交于
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由 Andre McCurdy 提交于
Update atomic.h to provide a_ctz_l in all cases (atomic_arch.h should now only provide a_ctz_32 and/or a_ctz_64). The generic version of a_ctz_32 now takes advantage of a_clz_32 if available and the generic a_ctz_64 now makes use of a_ctz_32.
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- 19 4月, 2018 8 次提交
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由 Marc André Tanner 提交于
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由 Rich Felker 提交于
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由 Rich Felker 提交于
bring these functions up to date with the current idioms we use/prefer in fmemopen and fopencookie.
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由 Rich Felker 提交于
rather than manually performing pointer arithmetic to carve multiple objects out of one allocation, use a containing struct that encompasses them all.
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由 Rich Felker 提交于
assign entire struct rather than member-at-a-time. don't repeat buffer sizes; always use sizeof to ensure consistency.
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由 Rich Felker 提交于
replacement is subject to conditions on the replacement functions. they may only call functions which are async-signal-safe, as specified either by POSIX or as an implementation-defined extension. if any allocator functions are replaced, at least malloc, realloc, and free must be provided. if calloc is not provided, it will behave as malloc+memset. any of the memalign-family functions not provided will fail with ENOMEM. in order to implement the above properties, calloc and __memalign check that they are using their own malloc or free, respectively. choice to check malloc or free is based on considerations of supporting __simple_malloc. in order to make this work, calloc is split into separate versions for __simple_malloc and full malloc; commit ba819787 already did most of the split anyway, and completing it saves an extra call frame. previously, use of -Bsymbolic-functions made dynamic interposition impossible. now, we are using an explicit dynamic-list, so add allocator functions to the list. most are not referenced anyway, but all are added for completeness.
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由 Rich Felker 提交于
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由 Rich Felker 提交于
instead of using a waiters count, add a bit to the lock field indicating that the lock may have waiters. threads which obtain the lock after contending for it will perform a potentially-spurious wake when they release the lock.
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- 18 4月, 2018 5 次提交
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由 Rich Felker 提交于
commit e3bc22f1 removed all references to __brk.
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由 Rich Felker 提交于
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由 Alexander Monakov 提交于
Split 'free' into unmap_chunk and bin_chunk, use the latter to introduce __malloc_donate and use it in reclaim_gaps instead of calling 'free'.
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由 Alexander Monakov 提交于
Fix an instance where realloc code would overallocate by OVERHEAD bytes amount. Manually arrange for reuse of memcpy-free-return exit sequence.
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由 Rich Felker 提交于
the Linux SYS_nice syscall is unusable because it does not return the newly set priority. always use SYS_setpriority. also avoid overflows in addition of inc by handling large inc values directly without examining the old nice value.
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- 12 4月, 2018 2 次提交
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由 Alexander Monakov 提交于
Implementation of __malloc0 in malloc.c takes care to preserve zero pages by overwriting only non-zero data. However, malloc must have already modified auxiliary heap data just before and beyond the allocated region, so we know that edge pages need not be preserved. For allocations smaller than one page, pass them immediately to memset. Otherwise, use memset to handle partial pages at the head and tail of the allocation, and scan complete pages in the interior. Optimize the scanning loop by processing 16 bytes per iteration and handling rest of page via memset as soon as a non-zero byte is found.
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由 Rich Felker 提交于
the catan implementation from OpenBSD includes a FIXME-annotated "overflow" branch that produces a meaningless and incorrect large-magnitude result. it was reachable via three paths, corresponding to gotos removed by this commit, in order: 1. pure imaginary argument with imaginary component greater than 1 in magnitude. this case does not seem at all exceptional and is handled (at least with the quality currently expected from our complex math functions) by the existing non-exceptional code path. 2. arguments on the unit circle, including the pure-real argument 1.0. these are not exceptional except for ±i, which should produce results with infinite imaginary component and which lead to computation of atan2(±0,0) in the existing non-exceptional code path. such calls to atan2() however are well-defined by POSIX. 3. the specific argument +i. this route should be unreachable due to the above (2), but subtle rounding effects might have made it possible in rare cases. continuing on the non-exceptional code path in this case would lead to computing the (real) log of an infinite argument, then producing a NAN when multiplying it by I. for now, remove the exceptional code paths entirely. replace the multiplication by I with construction of a complex number using the CMPLX macro so that the NAN issue (3) prevented cannot arise. with these changes, catan should give reasonably correct results for real arguments, and should no longer give completely-wrong results for pure-imaginary arguments outside the interval (-i,+i).
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- 10 4月, 2018 1 次提交
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由 Rich Felker 提交于
the factor of -i noted in the comment at the top of casin.c was omitted from the actual code, yielding a result rotated 90 degrees and propagating into errors in other functions defined in terms of casin. implement multiplication by -i as a rotation of the real and imaginary parts of the result, rather than by actual multiplication, since the latter cannot be optimized without knowledge that the operand is finite. here, the rotation is the actual intent, anyway.
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- 08 4月, 2018 1 次提交
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由 Samuel Holland 提交于
Commit 8a6bd730 added support for padding specifier extensions to strftime, but did not modify wcsftime. In the process, it added a parameter to __strftime_fmt_1 in strftime.c, but failed to update the prototype in wcsftime.c. This was found by compiling musl with LTO: src/time/wcsftime.c:7:13: warning: type of '__strftime_fmt_1' does \ not match original declaration [-Wlto-type-mismatch] Fix the prototype of __strftime_fmt_1 in wcsftime.c, and generate the 'pad' argument the same way as it is done in strftime.
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- 05 4月, 2018 1 次提交
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由 Rich Felker 提交于
it was reported by Erik Bosman that poll fails without setting revents when the nfds argument exceeds the current value for RLIMIT_NOFILE, causing the subsequent open calls to be bypassed. if the rlimit is either 1 or 2, this leaves fd 0 and 1 potentially closed but openable when the application code is reached. based on a brief reading of the poll syscall documentation and code, it may be possible for poll to fail under other attacker-controlled conditions as well. if it turns out these are reasonable conditions that may happen in the real world, we may have to go back and implement fallbacks to probe each fd individually if poll fails, but for now, keep things simple and treat all poll failures as fatal.
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- 03 4月, 2018 1 次提交
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由 Szabolcs Nagy 提交于
if double precision r=x*y+z is not a half way case between two single precision floats or it is an exact result then fmaf returns (float)r. however the exactness check was wrong when |x*y| < |z| and could cause incorrectly rounded result in nearest rounding mode when r is a half way case. fmaf(-0x1.26524ep-54, -0x1.cb7868p+11, 0x1.d10f5ep-29) was incorrectly rounded up to 0x1.d117ap-29 instead of 0x1.d1179ep-29. (exact result is 0x1.d1179efffffffecp-29, r is 0x1.d1179fp-29)
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- 08 3月, 2018 1 次提交
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由 Rich Felker 提交于
use of MB_CUR_MAX encoded a hidden dependency on the currently active locale for the calling thread, whereas nl_langinfo_l is supposed to report for the locale passed as an argument.
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- 26 2月, 2018 1 次提交
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由 Rich Felker 提交于
general policy is that all source files defining a public API or an ABI mechanism referenced by a public header should include the public header that declares the interface, so that the compiler or analysis tools can check the consistency of the declarations. Alexander Monakov pointed out a number of violations of this principle a few years back. fix them now.
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- 25 2月, 2018 7 次提交
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由 Rich Felker 提交于
add a member of appropriate type to the fpos_t union so that accesses are well-defined. use long long instead of off_t since off_t is not always exposed in stdio.h and there's no namespace-clean alias for it. access is still performed using pointer casts rather than by naming the union member as a matter of style; to the extent possible, the naming of fields in opaque types defined in the public headers is not treated as an API contract with the implementation. access via the pointer cast is valid as long as the union has a member of matching type.
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由 Rich Felker 提交于
previously this macro used an odd if/else form instead of the more idiomatic do/while(0), making it unsafe against omission of trailing semicolon. the omission would make the following statement conditional instead of producing an error.
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由 Rich Felker 提交于
this is the idiom that's used elsewhere and should be more efficient or at least no worse.
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由 Rich Felker 提交于
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由 Rich Felker 提交于
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由 Rich Felker 提交于
they seem to be relics of e3cd6c5c where this code was refactored from a check that previously masked against (F_ERR|F_NOWR) instead of just F_NOWR.
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由 Rich Felker 提交于
formally, calling readv with a zero-length first iov component should behave identically to calling read on just the second component, but presence of a zero-length iov component has triggered bugs in some kernels and performs significantly worse than a simple read on some file types.
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- 24 2月, 2018 3 次提交
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由 Rich Felker 提交于
the stdio FILE read backend's return type is size_t, not ssize_t, and all of the special (non-fd-backed) FILE types already return the number of bytes read (zero) on error or eof. only __stdio_read leaked a syscall error return into its return value. fread had a workaround for this behavior going all the way back to the original check-in. remove the workaround since it's no longer needed.
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由 Rich Felker 提交于
replace with simple conditional that doesn't rely on assumption that cnt is either 0 or -1.
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由 Rich Felker 提交于
the ':' in optstring has special meaning as a flag applying to the previous option character, or to getopt's error handling behavior when it appears at the beginning. don't also accept a "-:" option based on its presence.
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- 23 2月, 2018 2 次提交
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由 Rich Felker 提交于
based loosely on patch by Hauke Mehrtens; converted to wrap the public API of the underlying getrandom function rather than direct syscalls, so that if/when a fallback implementation of getrandom is added it will automatically get picked up by getentropy too.
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由 Hauke Mehrtens 提交于
This syscall is available since Linux 3.17 and was also implemented in glibc in version 2.25 using the same interfaces.
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