Build breakage (was: Re: git: 4ba9ad0dc316 - main - iflib: add assert to prevent out-of-bounds array access)

[Robert Watson]

With recent iflib/netmap commits, I'm getting the following on my cross-built 
GENERIC-MMCCAM-NODEBUG kernel, which is essentially the FreeBSD/arm64 
GENERIC-MMCCAM as in the tree, but with GENERIC-NODEBUG as the base.  This 
configuration built fine until this morning, but I've not had a chance to 
bisect to figure out which was the commit that triggered the breakage:

>>> stage 3.1: building everything
/usr/home/robert/cheri/freebsd/sys/net/iflib.c:2384:2: error: implicit 
declaration of function 'netmap_disable_all_rings' is invalid in C99 
[-Werror,-Wimplicit-function-declaration]
         netmap_disable_all_rings(ifp);
         ^
/usr/home/robert/cheri/freebsd/sys/net/iflib.c:2444:2: error: implicit 
declaration of function 'netmap_enable_all_rings' is invalid in C99 
[-Werror,-Wimplicit-function-declaration]
         netmap_enable_all_rings(ifp);
         ^
/usr/home/robert/cheri/freebsd/sys/net/iflib.c:2444:2: note: did you mean 
'netmap_disable_all_rings'?
/usr/home/robert/cheri/freebsd/sys/net/iflib.c:2384:2: note: 
'netmap_disable_all_rings' declared here
         netmap_disable_all_rings(ifp);
         ^
/usr/home/robert/cheri/freebsd/sys/net/iflib.c:2495:2: error: implicit 
declaration of function 'netmap_disable_all_rings' is invalid in C99 
[-Werror,-Wimplicit-function-declaration]
         netmap_disable_all_rings(ctx->ifc_ifp);
         ^
3 errors generated.
--- iflib.o ---
*** [iflib.o] Error code 1
make[2]: stopped in 
/usr/home/robert/cheri/build/freebsd-aarch64-build/usr/home/robert/cheri/freebsd/arm64.aarch64/sys/GENERIC-MMCCAM-NODEBUG
--- all_subdir_bge ---
--- modules-all ---
*** [modules-all] Error code 2
make[2]: stopped in 
/usr/home/robert/cheri/build/freebsd-aarch64-build/usr/home/robert/cheri/freebsd/arm64.aarch64/sys/GENERIC-MMCCAM-NODEBUG
2 errors
make[2]: stopped in 
/usr/home/robert/cheri/build/freebsd-aarch64-build/usr/home/robert/cheri/freebsd/arm64.aarch64/sys/GENERIC-MMCCAM-NODEBUG
--- buildkernel ---
--- buildkernel ---
Fatal error: Command `nice make -DDB_FROM_SRC -DNO_CLEAN 
-DI_REALLY_MEAN_NO_CLEAN -DNO_ROOT -DBUILD_WITH_STRICT_TMPPATH 
TARGET_ARCH=aarch64 TARGET=arm64 DEBUG_FLAGS=-g 
'LOCAL_XTOOL_DIRS=lib/libnetbsd usr.sbin/makefs usr.bin/mkimg' 
LD=/usr/bin/ld.lld XLD=/usr/bin/ld.lld 'HACK_EXTRA_FLAGS=-shared 
-fuse-ld=/usr/bin/ld.lld' TRAMP_LDFLAGS=-fuse-ld=/usr/bin/ld.lld 
KERNCONF=GENERIC-MMCCAM-NODEBUG -DWITHOUT_CLEAN -DWITH_TESTS -DWITHOUT_PROFILE 
-DWITHOUT_DEBUG_FILES -DWITHOUT_OFED -DWITHOUT_MAN -DWITH_GOOGLETEST 
-DWITHOUT_GCC -DWITHOUT_CLANG -DWITHOUT_LLD -DWITHOUT_LLDB 
-DWITHOUT_GCC_BOOTSTRAP -DWITHOUT_CLANG_BOOTSTRAP -DWITHOUT_LLD_BOOTSTRAP 
-DWITHOUT_LIB32 -DWITH_ELFTOOLCHAIN_BOOTSTRAP -DWITH_TOOLCHAIN 
-DWITHOUT_BINUTILS_BOOTSTRAP -s -de buildkernel -j6` failed with non-zero exit 
code 2




On Sun, 10 Jan 2021, Vincenzo Maffione wrote:

> The branch main has been updated by vmaffione:
>
> URL: https://cgit.FreeBSD.org/src/commit/?id=4ba9ad0dc316940f32065b05f24259f942c0692d
>
> commit 4ba9ad0dc316940f32065b05f24259f942c0692d
> Author:     Vincenzo Maffione <vmaffione at FreeBSD.org>
> AuthorDate: 2021-01-10 13:49:51 +0000
> Commit:     Vincenzo Maffione <vmaffione at FreeBSD.org>
> CommitDate: 2021-01-10 13:59:20 +0000
>
>    iflib: add assert to prevent out-of-bounds array access
>
>    The iflib_queues_alloc() allocates isc_nrxqs iflib_dma_info structs
>    for each rxqset, and links each struct to a different free list.
>    As a result, it must be isc_nrxqs >= isc_nfl (plus the completion
>    queue, if present).
>    Add an assertion to make this constraint explicit.
>
>    MFC after:      2 weeks
> ---
> sys/net/iflib.c | 9 ++++-----
> 1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/sys/net/iflib.c b/sys/net/iflib.c
> index 3de80ecaeb0c..e53c5031d3a7 100644
> --- a/sys/net/iflib.c
> +++ b/sys/net/iflib.c
> @@ -5547,11 +5547,14 @@ iflib_queues_alloc(if_ctx_t ctx)
> 	uint8_t nrxqs = sctx->isc_nrxqs;
> 	uint8_t ntxqs = sctx->isc_ntxqs;
> 	int nfree_lists = sctx->isc_nfl ? sctx->isc_nfl : 1;
> +	int fl_offset = (sctx->isc_flags & IFLIB_HAS_RXCQ ? 1 : 0);
> 	caddr_t *vaddrs;
> 	uint64_t *paddrs;
>
> 	KASSERT(ntxqs > 0, ("number of queues per qset must be at least 1"));
> 	KASSERT(nrxqs > 0, ("number of queues per qset must be at least 1"));
> +	KASSERT(nrxqs >= fl_offset + nfree_lists,
> +           ("there must be at least a rxq for each free list"));
>
> 	/* Allocate the TX ring struct memory */
> 	if (!(ctx->ifc_txqs =
> @@ -5659,11 +5662,7 @@ iflib_queues_alloc(if_ctx_t ctx)
> 		}
> 		rxq->ifr_ctx = ctx;
> 		rxq->ifr_id = i;
> -		if (sctx->isc_flags & IFLIB_HAS_RXCQ) {
> -			rxq->ifr_fl_offset = 1;
> -		} else {
> -			rxq->ifr_fl_offset = 0;
> -		}
> +		rxq->ifr_fl_offset = fl_offset;
> 		rxq->ifr_nfl = nfree_lists;
> 		if (!(fl =
> 			  (iflib_fl_t) malloc(sizeof(struct iflib_fl) * nfree_lists, M_IFLIB, M_NOWAIT | M_ZERO))) {
>