On 2024-06-13 09:34:14 [+0200], Gianfranco Costamagna wrote: > Hello, in Ubuntu, where the kernel is configured to forbid unaligned accesses > on armhf, the package FTBFS > (this should be reproducible also on some Debian buildd machines, this is why > I'm reporting as serious severity)
Isn't ARMv6+ double of unaligned access? armhf requires VFP so that should be something later. Or am I wrong here? > example of failure: > https://launchpadlibrarian.net/734963041/buildlog_ubuntu-oracular-armhf.clamav_1.3.1+dfsg-3ubuntu1_BUILDING.txt.gz … > The following patch makes sure the unaligned access is fixed: > > Description: resolve armhf failure to build from source. Instead of arguing with me, you could forward it directly to upstream and give a pointer to apply whatever upsteams did. > Author: Vladimir Petko <vladimir.pe...@canonical.com> > --- a/libclamav/special.c > +++ b/libclamav/special.c > @@ -48,7 +48,8 @@ > > int cli_check_mydoom_log(cli_ctx *ctx) > { > - const uint32_t *record; > + const uint32_t record[16]; > + const uint32_t mask = 0xffffffff; please get rid of mask and add your data pointer here. > uint32_t check, key; > fmap_t *map = ctx->fmap; > unsigned int blocks = map->len / (8 * 4); > @@ -59,14 +60,20 @@ > if (blocks > 5) > blocks = 5; > > - record = fmap_need_off_once(map, 0, 8 * 4 * blocks); > - if (!record) > + // returns unaligned memory block > + const char* data = fmap_need_off_once(map, 0, 8 * 4 * blocks); > + if (!data) > return CL_CLEAN; > + > while (blocks) { /* This wasn't probably intended but that's what the > current code does anyway */ > - if (record[--blocks] == 0xffffffff) > + unsigned int offset = --blocks; > + offset *=sizeof(uint32_t); > + // safe (but slow) on unaligned memory > + if (!memcmp(&data[offset], &mask, sizeof(uint32_t))) > return CL_CLEAN; something like | while (blocks) { /* This wasn't probably intended but that's what the current code does anyway */ | uint32_t local; | | memcpy(&local, &data[--blocks * sizeof(uint32_t)], sizeof(uint32_t)); | if (local == 0xffffffff) | return CL_CLEAN; I am halfway tempted to suggest a packed-wrapper but this would be best to consult upstream first. > } > - > + // copy into aligned array to perform bit operations > + memcpy(record, data, sizeof(record)); > key = ~be32_to_host(record[0]); > check = (be32_to_host(record[1]) ^ key) + > (be32_to_host(record[2]) ^ key) + Sebastian
