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* manual/setjmp.texi: Document MTASC-safety properties.

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Alexandre Oliva 2014-01-31 23:49:07 -02:00
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@ -1,3 +1,7 @@
2014-01-31 Alexandre Oliva <aoliva@redhat.com>
* manual/setjmp.texi: Document MTASC-safety properties.
2014-01-31 Alexandre Oliva <aoliva@redhat.com>
* manual/search.texi: Document MTASC-safety properties.

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manual/setjmp.texi
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@ -107,6 +107,10 @@ identify a specific place to return to.
@comment setjmp.h
@comment ISO
@deftypefn Macro int setjmp (jmp_buf @var{state})
@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
@c _setjmp ok
@c __sigsetjmp(!savemask) ok
@c __sigjmp_save(!savemask) ok, does not call sigprocmask
When called normally, @code{setjmp} stores information about the
execution state of the program in @var{state} and returns zero. If
@code{longjmp} is later used to perform a non-local exit to this
@ -116,6 +120,20 @@ execution state of the program in @var{state} and returns zero. If
@comment setjmp.h
@comment ISO
@deftypefun void longjmp (jmp_buf @var{state}, int @var{value})
@safety{@prelim{}@mtsafe{}@asunsafe{@ascuplugin{} @asucorrupt{} @asulock{/hurd}}@acunsafe{@acucorrupt{} @aculock{/hurd}}}
@c __libc_siglongjmp @ascuplugin @asucorrupt @asulock/hurd @acucorrupt @aculock/hurd
@c _longjmp_unwind @ascuplugin @asucorrupt @acucorrupt
@c __pthread_cleanup_upto @ascuplugin @asucorrupt @acucorrupt
@c plugins may be unsafe themselves, but even if they weren't, this
@c function isn't robust WRT async signals and cancellation:
@c cleanups aren't taken off the stack right away, only after all
@c cleanups have been run. This means that async-cancelling
@c longjmp, or interrupting longjmp with an async signal handler
@c that calls longjmp may run the same cleanups multiple times.
@c _JMPBUF_UNWINDS_ADJ ok
@c *cleanup_buf->__routine @ascuplugin
@c sigprocmask(SIG_SETMASK) dup @asulock/hurd @aculock/hurd
@c __longjmp ok
This function restores current execution to the state saved in
@var{state}, and continues execution from the call to @code{setjmp} that
established that return point. Returning from @code{setjmp} by means of
@ -199,6 +217,11 @@ information about the set of blocked signals.
@comment setjmp.h
@comment POSIX.1
@deftypefun int sigsetjmp (sigjmp_buf @var{state}, int @var{savesigs})
@safety{@prelim{}@mtsafe{}@asunsafe{@asulock{/hurd}}@acunsafe{@aculock{/hurd}}}
@c sigsetjmp @asulock/hurd @aculock/hurd
@c __sigsetjmp(savemask) @asulock/hurd @aculock/hurd
@c __sigjmp_save(savemask) @asulock/hurd @aculock/hurd
@c sigprocmask(SIG_BLOCK probe) dup @asulock/hurd @aculock/hurd
This is similar to @code{setjmp}. If @var{savesigs} is nonzero, the set
of blocked signals is saved in @var{state} and will be restored if a
@code{siglongjmp} is later performed with this @var{state}.
@ -207,6 +230,8 @@ of blocked signals is saved in @var{state} and will be restored if a
@comment setjmp.h
@comment POSIX.1
@deftypefun void siglongjmp (sigjmp_buf @var{state}, int @var{value})
@safety{@prelim{}@mtsafe{}@asunsafe{@ascuplugin{} @asucorrupt{} @asulock{/hurd}}@acunsafe{@acucorrupt{} @aculock{/hurd}}}
@c Alias to longjmp.
This is similar to @code{longjmp} except for the type of its @var{state}
argument. If the @code{sigsetjmp} call that set this @var{state} used a
nonzero @var{savesigs} flag, @code{siglongjmp} also restores the set of
@ -267,6 +292,10 @@ and modification happens through one of the following functions:
@comment ucontext.h
@comment SVID
@deftypefun int getcontext (ucontext_t *@var{ucp})
@safety{@prelim{}@mtsafe{@mtsrace{:ucp}}@assafe{}@acsafe{}}
@c Linux-only implementations in assembly, including sigprocmask
@c syscall. A few cases call the sigprocmask function, but that's safe
@c too. The ppc case is implemented in terms of a swapcontext syscall.
The @code{getcontext} function initializes the variable pointed to by
@var{ucp} with the context of the calling thread. The context contains
the content of the registers, the signal mask, and the current stack.
@ -293,6 +322,8 @@ used to do that.
@comment ucontext.h
@comment SVID
@deftypefun void makecontext (ucontext_t *@var{ucp}, void (*@var{func}) (void), int @var{argc}, @dots{})
@safety{@prelim{}@mtsafe{@mtsrace{:ucp}}@assafe{}@acsafe{}}
@c Linux-only implementations mostly in assembly, nothing unsafe.
The @var{ucp} parameter passed to the @code{makecontext} shall be
initialized by a call to @code{getcontext}. The context will be
@ -339,6 +370,15 @@ requires detection of the platform at compile time.
@comment ucontext.h
@comment SVID
@deftypefun int setcontext (const ucontext_t *@var{ucp})
@safety{@prelim{}@mtsafe{@mtsrace{:ucp}}@asunsafe{@asucorrupt{}}@acunsafe{@acucorrupt{}}}
@c Linux-only implementations mostly in assembly. Some ports use
@c sigreturn or swapcontext syscalls; others restore the signal mask
@c first and then proceed restore other registers in userland, which
@c leaves a window for cancellation or async signals with misaligned or
@c otherwise corrupt stack. ??? Switching to a different stack, or even
@c to an earlier state on the same stack, may conflict with pthread
@c cleanups. This is not quite MT-Unsafe, it's a different kind of
@c safety issue.
The @code{setcontext} function restores the context described by
@var{ucp}. The context is not modified and can be reused as often as
@ -372,6 +412,10 @@ there are situations where the current context has to be preserved.
@comment ucontext.h
@comment SVID
@deftypefun int swapcontext (ucontext_t *restrict @var{oucp}, const ucontext_t *restrict @var{ucp})
@safety{@prelim{}@mtsafe{@mtsrace{:oucp} @mtsrace{:ucp}}@asunsafe{@asucorrupt{}}@acunsafe{@acucorrupt{}}}
@c Linux-only implementations mostly in assembly. Some ports call or
@c inline getcontext and/or setcontext, adjusting the saved context in
@c between, so we inherit the potential issues of both.
The @code{swapcontext} function is similar to @code{setcontext} but
instead of just replacing the current context the latter is first saved