https://bugs.kde.org/show_bug.cgi?id=514297
--- Comment #28 from Mark Wielaard <[email protected]> --- (In reply to mcermak from comment #23) > > I think the safe_to_deref before the PRE_MEM_RASCIIZ might be a > > separate/generic issue > > Right. I've kept it a part of the patch for now to simplify testing. > Moreover my patch has one more unrelated bit (initialization of vki_sigset_t > saved in m_syswrap/syswrap-main.c) silencing my compiler complaints: > https://sourceware.org/git/?p=valgrind.git;a=blob;f=coregrind/m_syswrap/ > syswrap-main.c;h=7a1bbb40fa22ac33f4d12ac577ab75fd7979f4dc;hb=refs/heads/ > users/mcermak/try-bug514297#l354 What compiler complaint exactly? If at all possible we should just commit such fixups separately. > > Could you show how these programs use the guard pages ? > > Here is how a guard page is created for each new thread: > > f44 x86_64 # valgrind -d python3 -c 'import time, threading; > [threading.Thread(None, lambda: time.sleep(1)).start() for x in range(4)]' > 2> >(grep guard) > --98531:1: aspacem installing guard pages (addr=0x5a8a000, len=0x1000) > --98531:1: aspacem installing guard pages (addr=0x628f000, len=0x1000) > --98531:1: aspacem installing guard pages (addr=0x6a94000, len=0x1000) > --98531:1: aspacem installing guard pages (addr=0x7299000, len=0x1000) > f44 x86_64 # > > > Could you investigate how things work with > > memcheck/tests/descr_belowsp.vgtest ? > > Seems like the testcase is missing "In stack guard protected page" in the > output. This is supposed to come from coregrind/m_addrinfo.c:242: > > 236 if (seg != NULL && seg->kind == SkAnonC > 237 && !seg->hasR && !seg->hasW && !seg->hasX) { > 238 /* This looks a plausible guard page. Check if a is close to > 239 the start of stack (lowest byte). */ > 240 tid = find_tid_with_stack_containing (VG_PGROUNDUP(a+1)); > 241 if (tid != VG_INVALID_THREADID) > 242 stackPos = StackPos_guard_page; > > ... this apparently is a place where the new madvise guard page support > should be taken into account as well. > > May I get this new update reviewed / commented pretty please? -- You are receiving this mail because: You are watching all bug changes.
