[Qemu-devel] [Bug 883133] Re: qemu on ARM hosts asserts due to code buffer/libc heap conflict
** Changed in: qemu Status: Fix Committed => Fix Released -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/883133 Title: qemu on ARM hosts asserts due to code buffer/libc heap conflict Status in QEMU: Fix Released Status in Linaro QEMU: Fix Released Bug description: On ARM hosts qemu (about half the time) asserts on startup: qemu-system-i386: malloc.c:3096: sYSMALLOc: Assertion `(old_top == (((mbinptr) (((char *) &((av)->bins[((1) - 1) * 2])) - __builtin_offsetof (struct malloc_chunk, fd && old_size == 0) || ((unsigned long) (old_size) >= (unsigned long)__builtin_offsetof (struct malloc_chunk, fd_nextsize))+((2 * (sizeof(size_t))) - 1)) & ~((2 * (sizeof(size_t))) - 1))) && ((old_top)->size & 0x1) && ((unsigned long)old_end & pagemask) == 0)' failed. This turns out to be because code_gen_alloc() is using mmap(MAP_FIXED) to map the code buffer at address 0x0100UL, which is in the area glibc happens to be using for its heap. This tends to make the next malloc() abort, although occasionally the stars align and we pass that and fail weirdly later on. I suspect we need to drop the MAP_FIXED requirement and fix the TCG code to cope with emitting code for longer-range branches for calls to host fns etc (calls/branches within the generated code should be ok to keep using the short-range branch insn I think). There is already no guarantee that the generated code and the host C code are within short branch range of each other... To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/883133/+subscriptions
[Qemu-devel] [Bug 883133] Re: qemu on ARM hosts asserts due to code buffer/libc heap conflict
** Changed in: qemu-linaro Status: Fix Committed => Triaged ** Changed in: qemu-linaro Status: Triaged => Fix Released -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/883133 Title: qemu on ARM hosts asserts due to code buffer/libc heap conflict Status in QEMU: Fix Committed Status in Linaro QEMU: Fix Released Bug description: On ARM hosts qemu (about half the time) asserts on startup: qemu-system-i386: malloc.c:3096: sYSMALLOc: Assertion `(old_top == (((mbinptr) (((char *) &((av)->bins[((1) - 1) * 2])) - __builtin_offsetof (struct malloc_chunk, fd && old_size == 0) || ((unsigned long) (old_size) >= (unsigned long)__builtin_offsetof (struct malloc_chunk, fd_nextsize))+((2 * (sizeof(size_t))) - 1)) & ~((2 * (sizeof(size_t))) - 1))) && ((old_top)->size & 0x1) && ((unsigned long)old_end & pagemask) == 0)' failed. This turns out to be because code_gen_alloc() is using mmap(MAP_FIXED) to map the code buffer at address 0x0100UL, which is in the area glibc happens to be using for its heap. This tends to make the next malloc() abort, although occasionally the stars align and we pass that and fail weirdly later on. I suspect we need to drop the MAP_FIXED requirement and fix the TCG code to cope with emitting code for longer-range branches for calls to host fns etc (calls/branches within the generated code should be ok to keep using the short-range branch insn I think). There is already no guarantee that the generated code and the host C code are within short branch range of each other... To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/883133/+subscriptions
[Qemu-devel] [Bug 883133] Re: qemu on ARM hosts asserts due to code buffer/libc heap conflict
NB: this would typically only happen when the ARM host had address space randomization including brk randomization enabled (ie /proc/sys/kernel/randomize_va_space is 2). -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/883133 Title: qemu on ARM hosts asserts due to code buffer/libc heap conflict Status in QEMU: Fix Committed Status in Linaro QEMU: Fix Committed Bug description: On ARM hosts qemu (about half the time) asserts on startup: qemu-system-i386: malloc.c:3096: sYSMALLOc: Assertion `(old_top == (((mbinptr) (((char *) &((av)->bins[((1) - 1) * 2])) - __builtin_offsetof (struct malloc_chunk, fd && old_size == 0) || ((unsigned long) (old_size) >= (unsigned long)__builtin_offsetof (struct malloc_chunk, fd_nextsize))+((2 * (sizeof(size_t))) - 1)) & ~((2 * (sizeof(size_t))) - 1))) && ((old_top)->size & 0x1) && ((unsigned long)old_end & pagemask) == 0)' failed. This turns out to be because code_gen_alloc() is using mmap(MAP_FIXED) to map the code buffer at address 0x0100UL, which is in the area glibc happens to be using for its heap. This tends to make the next malloc() abort, although occasionally the stars align and we pass that and fail weirdly later on. I suspect we need to drop the MAP_FIXED requirement and fix the TCG code to cope with emitting code for longer-range branches for calls to host fns etc (calls/branches within the generated code should be ok to keep using the short-range branch insn I think). There is already no guarantee that the generated code and the host C code are within short branch range of each other... To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/883133/+subscriptions
[Qemu-devel] [Bug 883133] Re: qemu on ARM hosts asserts due to code buffer/libc heap conflict
** Changed in: qemu-linaro Importance: Undecided => Medium -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/883133 Title: qemu on ARM hosts asserts due to code buffer/libc heap conflict Status in QEMU: Fix Committed Status in Linaro QEMU: Fix Committed Bug description: On ARM hosts qemu (about half the time) asserts on startup: qemu-system-i386: malloc.c:3096: sYSMALLOc: Assertion `(old_top == (((mbinptr) (((char *) &((av)->bins[((1) - 1) * 2])) - __builtin_offsetof (struct malloc_chunk, fd && old_size == 0) || ((unsigned long) (old_size) >= (unsigned long)__builtin_offsetof (struct malloc_chunk, fd_nextsize))+((2 * (sizeof(size_t))) - 1)) & ~((2 * (sizeof(size_t))) - 1))) && ((old_top)->size & 0x1) && ((unsigned long)old_end & pagemask) == 0)' failed. This turns out to be because code_gen_alloc() is using mmap(MAP_FIXED) to map the code buffer at address 0x0100UL, which is in the area glibc happens to be using for its heap. This tends to make the next malloc() abort, although occasionally the stars align and we pass that and fail weirdly later on. I suspect we need to drop the MAP_FIXED requirement and fix the TCG code to cope with emitting code for longer-range branches for calls to host fns etc (calls/branches within the generated code should be ok to keep using the short-range branch insn I think). There is already no guarantee that the generated code and the host C code are within short branch range of each other... To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/883133/+subscriptions
[Qemu-devel] [Bug 883133] Re: qemu on ARM hosts asserts due to code buffer/libc heap conflict
** Changed in: qemu-linaro Status: In Progress => Fix Committed -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/883133 Title: qemu on ARM hosts asserts due to code buffer/libc heap conflict Status in QEMU: Fix Committed Status in Linaro QEMU: Fix Committed Bug description: On ARM hosts qemu (about half the time) asserts on startup: qemu-system-i386: malloc.c:3096: sYSMALLOc: Assertion `(old_top == (((mbinptr) (((char *) &((av)->bins[((1) - 1) * 2])) - __builtin_offsetof (struct malloc_chunk, fd && old_size == 0) || ((unsigned long) (old_size) >= (unsigned long)__builtin_offsetof (struct malloc_chunk, fd_nextsize))+((2 * (sizeof(size_t))) - 1)) & ~((2 * (sizeof(size_t))) - 1))) && ((old_top)->size & 0x1) && ((unsigned long)old_end & pagemask) == 0)' failed. This turns out to be because code_gen_alloc() is using mmap(MAP_FIXED) to map the code buffer at address 0x0100UL, which is in the area glibc happens to be using for its heap. This tends to make the next malloc() abort, although occasionally the stars align and we pass that and fail weirdly later on. I suspect we need to drop the MAP_FIXED requirement and fix the TCG code to cope with emitting code for longer-range branches for calls to host fns etc (calls/branches within the generated code should be ok to keep using the short-range branch insn I think). There is already no guarantee that the generated code and the host C code are within short branch range of each other... To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/883133/+subscriptions
[Qemu-devel] [Bug 883133] Re: qemu on ARM hosts asserts due to code buffer/libc heap conflict
** Changed in: qemu Status: New => Fix Committed -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/883133 Title: qemu on ARM hosts asserts due to code buffer/libc heap conflict Status in QEMU: Fix Committed Status in Linaro QEMU: In Progress Bug description: On ARM hosts qemu (about half the time) asserts on startup: qemu-system-i386: malloc.c:3096: sYSMALLOc: Assertion `(old_top == (((mbinptr) (((char *) &((av)->bins[((1) - 1) * 2])) - __builtin_offsetof (struct malloc_chunk, fd && old_size == 0) || ((unsigned long) (old_size) >= (unsigned long)__builtin_offsetof (struct malloc_chunk, fd_nextsize))+((2 * (sizeof(size_t))) - 1)) & ~((2 * (sizeof(size_t))) - 1))) && ((old_top)->size & 0x1) && ((unsigned long)old_end & pagemask) == 0)' failed. This turns out to be because code_gen_alloc() is using mmap(MAP_FIXED) to map the code buffer at address 0x0100UL, which is in the area glibc happens to be using for its heap. This tends to make the next malloc() abort, although occasionally the stars align and we pass that and fail weirdly later on. I suspect we need to drop the MAP_FIXED requirement and fix the TCG code to cope with emitting code for longer-range branches for calls to host fns etc (calls/branches within the generated code should be ok to keep using the short-range branch insn I think). There is already no guarantee that the generated code and the host C code are within short branch range of each other... To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/883133/+subscriptions
[Qemu-devel] [Bug 883133] Re: qemu on ARM hosts asserts due to code buffer/libc heap conflict
Fix pushed into QEMU upstream today. -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/883133 Title: qemu on ARM hosts asserts due to code buffer/libc heap conflict Status in QEMU: New Status in Linaro QEMU: In Progress Bug description: On ARM hosts qemu (about half the time) asserts on startup: qemu-system-i386: malloc.c:3096: sYSMALLOc: Assertion `(old_top == (((mbinptr) (((char *) &((av)->bins[((1) - 1) * 2])) - __builtin_offsetof (struct malloc_chunk, fd && old_size == 0) || ((unsigned long) (old_size) >= (unsigned long)__builtin_offsetof (struct malloc_chunk, fd_nextsize))+((2 * (sizeof(size_t))) - 1)) & ~((2 * (sizeof(size_t))) - 1))) && ((old_top)->size & 0x1) && ((unsigned long)old_end & pagemask) == 0)' failed. This turns out to be because code_gen_alloc() is using mmap(MAP_FIXED) to map the code buffer at address 0x0100UL, which is in the area glibc happens to be using for its heap. This tends to make the next malloc() abort, although occasionally the stars align and we pass that and fail weirdly later on. I suspect we need to drop the MAP_FIXED requirement and fix the TCG code to cope with emitting code for longer-range branches for calls to host fns etc (calls/branches within the generated code should be ok to keep using the short-range branch insn I think). There is already no guarantee that the generated code and the host C code are within short branch range of each other... To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/883133/+subscriptions
[Qemu-devel] [Bug 883133] Re: qemu on ARM hosts asserts due to code buffer/libc heap conflict
** Changed in: qemu-linaro Assignee: (unassigned) => Dr. David Alan Gilbert (davidgil-uk) ** Changed in: qemu-linaro Status: New => In Progress -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/883133 Title: qemu on ARM hosts asserts due to code buffer/libc heap conflict Status in QEMU: New Status in Linaro QEMU: In Progress Bug description: On ARM hosts qemu (about half the time) asserts on startup: qemu-system-i386: malloc.c:3096: sYSMALLOc: Assertion `(old_top == (((mbinptr) (((char *) &((av)->bins[((1) - 1) * 2])) - __builtin_offsetof (struct malloc_chunk, fd && old_size == 0) || ((unsigned long) (old_size) >= (unsigned long)__builtin_offsetof (struct malloc_chunk, fd_nextsize))+((2 * (sizeof(size_t))) - 1)) & ~((2 * (sizeof(size_t))) - 1))) && ((old_top)->size & 0x1) && ((unsigned long)old_end & pagemask) == 0)' failed. This turns out to be because code_gen_alloc() is using mmap(MAP_FIXED) to map the code buffer at address 0x0100UL, which is in the area glibc happens to be using for its heap. This tends to make the next malloc() abort, although occasionally the stars align and we pass that and fail weirdly later on. I suspect we need to drop the MAP_FIXED requirement and fix the TCG code to cope with emitting code for longer-range branches for calls to host fns etc (calls/branches within the generated code should be ok to keep using the short-range branch insn I think). There is already no guarantee that the generated code and the host C code are within short branch range of each other... To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/883133/+subscriptions
[Qemu-devel] [Bug 883133] Re: qemu on ARM hosts asserts due to code buffer/libc heap conflict
** Also affects: qemu Importance: Undecided Status: New -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/883133 Title: qemu on ARM hosts asserts due to code buffer/libc heap conflict Status in QEMU: New Status in Linaro QEMU: New Bug description: On ARM hosts qemu (about half the time) asserts on startup: qemu-system-i386: malloc.c:3096: sYSMALLOc: Assertion `(old_top == (((mbinptr) (((char *) &((av)->bins[((1) - 1) * 2])) - __builtin_offsetof (struct malloc_chunk, fd && old_size == 0) || ((unsigned long) (old_size) >= (unsigned long)__builtin_offsetof (struct malloc_chunk, fd_nextsize))+((2 * (sizeof(size_t))) - 1)) & ~((2 * (sizeof(size_t))) - 1))) && ((old_top)->size & 0x1) && ((unsigned long)old_end & pagemask) == 0)' failed. This turns out to be because code_gen_alloc() is using mmap(MAP_FIXED) to map the code buffer at address 0x0100UL, which is in the area glibc happens to be using for its heap. This tends to make the next malloc() abort, although occasionally the stars align and we pass that and fail weirdly later on. I suspect we need to drop the MAP_FIXED requirement and fix the TCG code to cope with emitting code for longer-range branches for calls to host fns etc (calls/branches within the generated code should be ok to keep using the short-range branch insn I think). There is already no guarantee that the generated code and the host C code are within short branch range of each other... To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/883133/+subscriptions