kernel/linux.git/include/linux/overflow.h, branch v5.16.12

compiler.h: drop fallback overflow checkers

2021-09-13T17:18:28+00:00

Once upgrading the minimum supported version of GCC to 5.1, we can drop the fallback code for !COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW. This is effectively a revert of commit f0907827a8a9 ("compiler.h: enable builtin overflow checkers and add fallback code") Link: https://github.com/ClangBuiltLinux/linux/issues/1438#issuecomment-916745801 Suggested-by: Rasmus Villemoes Signed-off-by: Nick Desaulniers Acked-by: Kees Cook Reviewed-by: Nathan Chancellor Signed-off-by: Linus Torvalds

overflow: Correct check_shl_overflow() comment

2021-04-01T21:07:41+00:00

A 'false' return means the value was safely set, so the comment should say 'true' for when it is not considered safe. Cc: Jason Gunthorpe Signed-off-by: Keith Busch Signed-off-by: Kees Cook Fixes: 0c66847793d1 ("overflow.h: Add arithmetic shift helper") Link: https://lore.kernel.org/r/20210401160629.1941787-1-kbusch@kernel.org

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma

2020-10-17T18:18:18+00:00

Pull rdma updates from Jason Gunthorpe: "A usual cycle for RDMA with a typical mix of driver and core subsystem updates: - Driver minor changes and bug fixes for mlx5, efa, rxe, vmw_pvrdma, hns, usnic, qib, qedr, cxgb4, hns, bnxt_re - Various rtrs fixes and updates - Bug fix for mlx4 CM emulation for virtualization scenarios where MRA wasn't working right - Use tracepoints instead of pr_debug in the CM code - Scrub the locking in ucma and cma to close more syzkaller bugs - Use tasklet_setup in the subsystem - Revert the idea that 'destroy' operations are not allowed to fail at the driver level. This proved unworkable from a HW perspective. - Revise how the umem API works so drivers make fewer mistakes using it - XRC support for qedr - Convert uverbs objects RWQ and MW to new the allocation scheme - Large queue entry sizes for hns - Use hmm_range_fault() for mlx5 On Demand Paging - uverbs APIs to inspect the GID table instead of sysfs - Move some of the RDMA code for building large page SGLs into lib/scatterlist" * tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (191 commits) RDMA/ucma: Fix use after free in destroy id flow RDMA/rxe: Handle skb_clone() failure in rxe_recv.c RDMA/rxe: Move the definitions for rxe_av.network_type to uAPI RDMA: Explicitly pass in the dma_device to ib_register_device lib/scatterlist: Do not limit max_segment to PAGE_ALIGNED values IB/mlx4: Convert rej_tmout radix-tree to XArray RDMA/rxe: Fix bug rejecting all multicast packets RDMA/rxe: Fix skb lifetime in rxe_rcv_mcast_pkt() RDMA/rxe: Remove duplicate entries in struct rxe_mr IB/hfi,rdmavt,qib,opa_vnic: Update MAINTAINERS IB/rdmavt: Fix sizeof mismatch MAINTAINERS: CISCO VIC LOW LATENCY NIC DRIVER RDMA/bnxt_re: Fix sizeof mismatch for allocation of pbl_tbl. RDMA/bnxt_re: Use rdma_umem_for_each_dma_block() RDMA/umem: Move to allocate SG table from pages lib/scatterlist: Add support in dynamic allocation of SG table from pages tools/testing/scatterlist: Show errors in human readable form tools/testing/scatterlist: Rejuvenate bit-rotten test RDMA/ipoib: Set rtnl_link_ops for ipoib interfaces RDMA/uverbs: Expose the new GID query API to user space ...

overflow: Add __must_check attribute to check_*() helpers

2020-10-12T22:19:07+00:00

Since the destination variable of the check_*_overflow() helpers will contain a wrapped value on failure, it would be best to make sure callers really did check the return result of the helper. Adjust the macros to use a bool-wrapping static inline that is marked with __must_check. This means the macros can continue to have their type-agnostic behavior while gaining the function attribute (that cannot be applied directly to macros). Suggested-by: Rasmus Villemoes Link: https://lore.kernel.org/lkml/202008151007.EF679DF@keescook/ Signed-off-by: Kees Cook

overflow: Include header file with SIZE_MAX declaration

2020-10-02T00:20:11+00:00

The various array_size functions use SIZE_MAX define, but missed limits.h causes to failure to compile code that needs overflow.h. In file included from drivers/infiniband/core/uverbs_std_types_device.c:6: ./include/linux/overflow.h: In function 'array_size': ./include/linux/overflow.h:258:10: error: 'SIZE_MAX' undeclared (first use in this function) 258 | return SIZE_MAX; | ^~~~~~~~ Fixes: 610b15c50e86 ("overflow.h: Add allocation size calculation helpers") Link: https://lore.kernel.org/r/20200913102928.134985-1-leon@kernel.org Signed-off-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe

overflow.h: Add flex_array_size() helper

2020-06-17T03:45:08+00:00

Add flex_array_size() helper for the calculation of the size, in bytes, of a flexible array member contained within an enclosing structure. Example of usage: struct something { size_t count; struct foo items[]; }; struct something *instance; instance = kmalloc(struct_size(instance, items, count), GFP_KERNEL); instance->count = count; memcpy(instance->items, src, flex_array_size(instance, items, instance->count)); The helper returns SIZE_MAX on overflow instead of wrapping around. Additionally replaces parameter "n" with "count" in struct_size() helper for greater clarity and unification. Signed-off-by: Gustavo A. R. Silva Link: https://lore.kernel.org/r/20200609012233.GA3371@embeddedor Signed-off-by: Kees Cook

Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2019-05-16T17:29:00+00:00

Pull core fixes from Ingo Molnar: "A handful of objtool updates, plus a documentation addition for __ab_c_size()" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: objtool: Fix whitelist documentation typo objtool: Fix function fallthrough detection objtool: Don't use ignore flag for fake jumps overflow.h: Add comment documenting __ab_c_size()

overflow.h: Add comment documenting __ab_c_size()

2019-04-12T11:44:24+00:00

__ab_c_size() is a somewhat opaque name. Document its purpose, and while at it, rename the parameters to actually match the abc naming. [ bp: glued a complete patch from chunks on LKML. ] Reported-by: Borislav Petkov Signed-off-by: Rasmus Villemoes Signed-off-by: Borislav Petkov Acked-by: Kees Cook Cc: Matthew Wilcox Link: https://lkml.kernel.org/r/20190405045711.30339-1-bp@alien8.de

overflow: Fix -Wtype-limits compilation warnings

2019-03-27T13:23:03+00:00

Attempt to use check_shl_overflow() with inputs of unsigned type produces the following compilation warnings. drivers/infiniband/hw/mlx5/qp.c: In function _set_user_rq_size_: ./include/linux/overflow.h:230:6: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits] _s >= 0 && _s < 8 * sizeof(*d) ? _s : 0; \ ^~ drivers/infiniband/hw/mlx5/qp.c:5820:6: note: in expansion of macro _check_shl_overflow_ if (check_shl_overflow(rwq->wqe_count, rwq->wqe_shift, &rwq->buf_size)) ^~~~~~~~~~~~~~~~~~ ./include/linux/overflow.h:232:26: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] (_to_shift != _s || *_d < 0 || _a < 0 || \ ^ drivers/infiniband/hw/mlx5/qp.c:5820:6: note: in expansion of macro _check_shl_overflow_ if (check_shl_overflow(rwq->wqe_count, rwq->wqe_shift, &rwq->buf_size)) ^~~~~~~~~~~~~~~~~~ ./include/linux/overflow.h:232:36: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] (_to_shift != _s || *_d < 0 || _a < 0 || \ ^ drivers/infiniband/hw/mlx5/qp.c:5820:6: note: in expansion of macro _check_shl_overflow_ if (check_shl_overflow(rwq->wqe_count, rwq->wqe_shift,&rwq->buf_size)) ^~~~~~~~~~~~~~~~~~ Fixes: 0c66847793d1 ("overflow.h: Add arithmetic shift helper") Reviewed-by: Bart Van Assche Acked-by: Kees Cook Signed-off-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe

overflow.h: Add arithmetic shift helper

2018-08-08T15:47:26+00:00

Add shift_overflow() helper to assist driver authors in ensuring that shift operations don't cause overflows or other odd conditions. Signed-off-by: Jason Gunthorpe Signed-off-by: Leon Romanovsky [kees: tweaked comments and commit log, dropped unneeded assignment] Signed-off-by: Kees Cook