Re: [PATCH v3 00/40] Fix build on gcc8 and various bugs

[Luca Boccassi <bluca@debian.org>]

On Thu, 2018-05-10 at 20:23 +0800, Andy Green wrote:
> 
> On 05/10/2018 06:21 PM, Luca Boccassi wrote:
> > On Thu, 2018-05-10 at 10:46 +0800, Andy Green wrote:
> > > The following series gets current master able to build
> > > itself, and allow lagopus to build against it, on Fedora 28 +
> > > x86_64 using gcc 8.0.1.
> > > 
> > > The first 17 patches have already been through two spins and
> > > this time are corrected for all the comment (thanks to
> > > everybody who commented) since v2, and have tested-by /
> > > acked-bys applied.  The first workaround patch for the hash
> > > function cast problem is dropped since something has already
> > > been applied in master since yesterday to address it.
> > > 
> > > The additional 23 patches are fixes for problems found
> > > actually trying to build lagopus using current master.
> > > These are almost entirely related to signed / unsigned
> > > or truncation without explicit casts inside dpdk
> > > headers.
> > > 
> > > ---
> > > 
> > > Andy Green (40):
> > >        drivers/bus/pci: fix strncpy dangerous code
> > >        drivers/bus/dpaa: fix inconsistent struct alignment
> > >        drivers/net/axgbe: fix broken eeprom string comp
> > >        drivers/net/nfp/nfpcore: fix strncpy misuse
> > >        drivers/net/nfp/nfpcore: fix off-by-one and no NUL on
> > > strncpy
> > > use
> > >        drivers/net/nfp: don't memcpy out of source range
> > >        drivers/net/nfp: fix buffer overflow in fw_name
> > >        drivers/net/qede: fix strncpy constant and NUL
> > >        drivers/net/qede: fix broken strncpy
> > >        drivers/net/sfc: fix strncpy length
> > >        drivers/net/sfc: fix strncpy size and NUL
> > >        drivers/net/vdev: readlink inputs cannot be aliased
> > >        drivers/net/vdev: fix 3 x strncpy misuse
> > >        app/test-pmd: can't find include
> > >        app/proc-info: fix sprintf overrun bug
> > >        app/test-bbdev: test-bbdev: strcpy ok for allocated string
> > >        app/test-bbdev: strcpy ok for allocated string
> > >        rte_common.h: cast gcc builtin result to avoid complaints
> > >        rte_memcpy.h: explicit tmp cast
> > >        lib/librte_eal/common/include/rte_lcore.h: explicit cast
> > > for
> > > signed change
> > >        /lib/librte_eal/common/include/rte_random.h: stage cast
> > > from
> > > uint64_t to long
> > >        rte_spinlock.h: stack declarations before code
> > >        rte_ring_generic.h: stack declarations before code
> > >        rte_ring.h: remove signed type flipflopping
> > >        rte_dev.h: stack declaration at top of own basic block
> > >        rte_mbuf.h: avoid truncation warnings from inadvertant
> > > int16_t
> > > to int promotion
> > >        rte_mbuf.h: explicit casts for flipping between int16_t
> > > and
> > > uint16_t
> > >        rte_mbuf.h: make sure RTE_MIN compares same types
> > >        rte_mbuf.h: explicit cast restricting ptrdiff to uint16_t
> > >        rte_mbuf.h: explicit cast for size_t to uint32_t
> > >        rte_mbuf.h: explicit casts to uint16_t to avoid truncation
> > > warnings
> > >        rte_byteorder.h: explicit cast for return promotion
> > >        rte_ether.h: explicit cast avoiding truncation warning
> > >        rte_ether.h: stack vars declared at top of function
> > >        rte_ethdev.h: fix sign and scope of temp var
> > >        rte_ethdev.h: explicit cast for return type
> > >        rte_ethdev.h: explicit cast for truncation
> > >        rte_hash_crc.h: stack vars declared at top of function
> > >        rte_hash_crc.h: explicit casts for truncation
> > >        rte_string_fns.h: explicit cast for int return to size_t
> > 
> > Hi,
> > 
> > I've built-tested this series on Debian Stretch (gcc 6.3) and
> > Debian
> > Sid (gcc 8.1).
> > 
> > The series builds fine with the default config, but the bnx2x and
> > mlx5
> > PMDs still have errors with gcc-8:
> 
> Yes I just built it with defconfig for x86_64 on Fedora 28 with
> default 
> tools and cleared out everything that came up.
> 
> > /tmp/dpdk/drivers/net/bnx2x/bnx2x.c: In function
> > 'bnx2x_alloc_hsi_mem':
> > /tmp/dpdk/drivers/net/bnx2x/bnx2x.c:176:29: error: '%s' directive
> > writing up to 31 bytes into a region of size between 15 and 25 [-
> > Werror=format-overflow=]
> >     sprintf(mz_name, "bnx2x%d_%s_%" PRIx64, sc->pcie_device, msg,
> >                               ^~
> > /tmp/dpdk/drivers/net/bnx2x/bnx2x.c:8874:7:
> >     if (bnx2x_dma_alloc(sc, sizeof(union
> > bnx2x_host_hc_status_block),
> >         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > ~~
> >         &fp->sb_dma, buf, RTE_CACHE_LINE_SIZE) != 0) {
> >         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > /tmp/dpdk/drivers/net/bnx2x/bnx2x.c:176:3: note: 'sprintf' output
> > between 10 and 66 bytes into a destination of size 32
> >     sprintf(mz_name, "bnx2x%d_%s_%" PRIx64, sc->pcie_device, msg,
> >     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >      rte_get_timer_cycles());
> >      ~~~~~~~~~~~~~~~~~~~~~~~
> > /tmp/dpdk/drivers/net/bnx2x/bnx2x.c:173:29: error: '%s' directive
> > writing up to 31 bytes into a region of size between 23 and 25 [-
> > Werror=format-overflow=]
> >     sprintf(mz_name, "bnx2x%d_%s_%" PRIx64, SC_ABS_FUNC(sc), msg,
> >                               ^~
> > /tmp/dpdk/drivers/net/bnx2x/bnx2x.c:8874:7:
> >     if (bnx2x_dma_alloc(sc, sizeof(union
> > bnx2x_host_hc_status_block),
> >         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > ~~
> >         &fp->sb_dma, buf, RTE_CACHE_LINE_SIZE) != 0) {
> >         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > /tmp/dpdk/drivers/net/bnx2x/bnx2x.c:173:3: note: 'sprintf' output
> > between 10 and 58 bytes into a destination of size 32
> >     sprintf(mz_name, "bnx2x%d_%s_%" PRIx64, SC_ABS_FUNC(sc), msg,
> >     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >      rte_get_timer_cycles());
> > 
> > 
> > /tmp/dpdk/drivers/net/mlx5/mlx5.c: In function 'mlx5_pci_probe':
> > /tmp/dpdk/drivers/net/mlx5/mlx5.c:920:13: error: 'vf' may be used
> > uninitialized in this function [-Werror=maybe-uninitialized]
> >     config.vf = vf;
> > 
> > Hope this can be useful.
> 
> I think gcc 8.0.1 is capable to show that and I am willing to look
> at 
> them.  But can you help me with exactly what changes you made so
> these 
> things built and made trouble, compared to the defconfig I have used 
> until now?

If you already have a build directory you are using, the simplest way
is to edit the .config file in there and change the following from =n
to =y:

CONFIG_RTE_LIBRTE_MLX4_PMD
CONFIG_RTE_LIBRTE_MLX5_PMD
CONFIG_RTE_LIBRTE_BNX2X_PMD

Then rebuild and you should see the errors.

-- 
Kind regards,
Luca Boccassi