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(perl #131844) fix various space calculation issues in pp_pack.c - for the originally reported case, if the start/cur pointer is in the top 75% of the address space the add (cur) + glen addition would overflow, resulting in the condition failing incorrectly. - the addition of the existing space used to the space needed could overflow, resulting in too small an allocation and a buffer overflow. - the scaling for UTF8 could overflow. - the multiply to calculate the space needed for many items could overflow. For the first case, do a space calculation without making new pointers. For the other cases, detect the overflow and croak if there's an overflow. Originally this used Size_t_MAX as the maximum size of a memory allocation, but for -DDEBUGGING builds realloc() throws a panic for allocations over half the address space in size, changing the error reported for the allocation. For non-DEBUGGING builds the Size_t_MAX limit has the small chance of finding a system that has 3GB of contiguous space available, and allocating that space, which could be a denial of servce in some cases. Unfortunately changing the limit to half the address space means that the exact case with the original issue can no longer occur, so the test is no longer testing against the address + length issue that caused the original problem, since the allocation is failing earlier. One option would be to change the test so the size request by pack is just under 2GB, but this has a higher (but still low) probability that the system has the address space available, and will actually try to allocate the memory, so let's not do that. Note: changed plan tests => 14713; to plan tests => 14712; in a/t/op/pack.t to apply this patch on perl 5.24.1. Affects perl < 5.26.2 (From OE-Core rev: 0542779d2f1a8977a732800a8998fd88971c0c1d) Signed-off-by: Jagadeesh Krishnanjanappa <jkrishnanjanappa@mvista.com> Signed-off-by: Armin Kuster <akuster808@gmail.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
QEMU Emulation Targets ====================== To simplify development, the build system supports building images to work with the QEMU emulator in system emulation mode. Several architectures are currently supported in 32 and 64 bit variants: * ARM (qemuarm + qemuarm64) * x86 (qemux86 + qemux86-64) * PowerPC (qemuppc only) * MIPS (qemumips + qemumips64) Use of the QEMU images is covered in the Yocto Project Reference Manual. The appropriate MACHINE variable value corresponding to the target is given in brackets.