From 6ab7e5465a4d6188e29398fb43a30dbab1015b75 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Wed, 20 Feb 2013 15:21:09 +0000 Subject: Replace all setjmp()/longjmp() with sigsetjmp()/siglongjmp() The setjmp() function doesn't specify whether signal masks are saved and restored; on Linux they are not, but on BSD (including MacOSX) they are. We want to have consistent behaviour across platforms, so we should always use "don't save/restore signal mask" (this is also generally going to be faster). This also works around a bug in MacOSX where the signal-restoration on longjmp() affects the signal mask for a completely different thread, not just the mask for the thread which did the longjmp. The most visible effect of this was that ctrl-C was ignored on MacOSX because the CPU thread did a longjmp which resulted in its signal mask being applied to every thread, so that all threads had SIGINT and SIGTERM blocked. The POSIX-sanctioned portable way to do a jump without affecting signal masks is to siglongjmp() to a sigjmp_buf which was created by calling sigsetjmp() with a zero savemask parameter, so change all uses of setjmp()/longjmp() accordingly. [Technically POSIX allows sigsetjmp(buf, 0) to save the signal mask; however the following siglongjmp() must not restore the signal mask, so the pair can be effectively considered as "sigjmp/longjmp which don't touch the mask".] For Windows we provide a trivial sigsetjmp/siglongjmp in terms of setjmp/longjmp -- this is OK because no user will ever pass a non-zero savemask. The setjmp() uses in tests/tcg/test-i386.c and tests/tcg/linux-test.c are left untouched because these are self-contained singlethreaded test programs intended to be run under QEMU's Linux emulation, so they have neither the portability nor the multithreading issues to deal with. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Tested-by: Stefan Weil Reviewed-by: Laszlo Ersek Signed-off-by: Blue Swirl --- disas/i386.c | 6 +++--- disas/m68k.c | 11 ++++++----- 2 files changed, 9 insertions(+), 8 deletions(-) (limited to 'disas') diff --git a/disas/i386.c b/disas/i386.c index dbecf1ffb5..73cc06f1c3 100644 --- a/disas/i386.c +++ b/disas/i386.c @@ -226,7 +226,7 @@ struct dis_private { bfd_byte the_buffer[MAX_MNEM_SIZE]; bfd_vma insn_start; int orig_sizeflag; - jmp_buf bailout; + sigjmp_buf bailout; }; enum address_mode @@ -303,7 +303,7 @@ fetch_data2(struct disassemble_info *info, bfd_byte *addr) STATUS. */ if (priv->max_fetched == priv->the_buffer) (*info->memory_error_func) (status, start, info); - longjmp (priv->bailout, 1); + siglongjmp(priv->bailout, 1); } else priv->max_fetched = addr; @@ -3661,7 +3661,7 @@ print_insn (bfd_vma pc, disassemble_info *info) start_codep = priv.the_buffer; codep = priv.the_buffer; - if (setjmp (priv.bailout) != 0) + if (sigsetjmp(priv.bailout, 0) != 0) { const char *name; diff --git a/disas/m68k.c b/disas/m68k.c index c950241f79..cc0db96cae 100644 --- a/disas/m68k.c +++ b/disas/m68k.c @@ -624,7 +624,7 @@ struct private bfd_byte *max_fetched; bfd_byte the_buffer[MAXLEN]; bfd_vma insn_start; - jmp_buf bailout; + sigjmp_buf bailout; }; /* Make sure that bytes from INFO->PRIVATE_DATA->BUFFER (inclusive) @@ -644,7 +644,7 @@ fetch_data2(struct disassemble_info *info, bfd_byte *addr) if (status != 0) { (*info->memory_error_func) (status, start, info); - longjmp (priv->bailout, 1); + siglongjmp(priv->bailout, 1); } else priv->max_fetched = addr; @@ -1912,9 +1912,10 @@ print_insn_m68k (bfd_vma memaddr, disassemble_info *info) priv.max_fetched = priv.the_buffer; priv.insn_start = memaddr; - if (setjmp (priv.bailout) != 0) - /* Error return. */ - return -1; + if (sigsetjmp(priv.bailout, 0) != 0) { + /* Error return. */ + return -1; + } switch (info->mach) { -- cgit v1.2.1