[Bug 1178241] New: Building cilium on x86_64 fails after LLVM 11 update
http://bugzilla.opensuse.org/show_bug.cgi?id=1178241 Bug ID: 1178241 Summary: Building cilium on x86_64 fails after LLVM 11 update Classification: openSUSE Product: openSUSE Tumbleweed Version: Current Hardware: Other OS: Other Status: NEW Severity: Normal Priority: P5 - None Component: Kubic Assignee: kubic-bugs@opensuse.org Reporter: aaronpuchert@alice-dsl.net QA Contact: qa-bugs@suse.de Found By: --- Blocker: --- There is a new default warning, and cilium builds with -Werror: /home/abuild/rpmbuild/BUILD/go/src/github.com/cilium/cilium/bpf/lib/dbg.h:168:13: error: cast to smaller integer type '__u32' (aka 'unsigned int') from '__u32 *' (aka 'unsigned int *') [-Werror,-Wpointer-to-int-cast] .source = EVENT_SOURCE, ^~~~~~~~~~~~ bpf_lxc.c:21:22: note: expanded from macro 'EVENT_SOURCE' #define EVENT_SOURCE LXC_ID ^~~~~~ /home/abuild/rpmbuild/BUILD/go/src/github.com/cilium/cilium/bpf/lxc_config.h:28:16: note: expanded from macro 'LXC_ID' #define LXC_ID fetch_u32(LXC_ID) ^~~~~~~~~~~~~~~~~ /home/abuild/rpmbuild/BUILD/go/src/github.com/cilium/cilium/bpf/lib/utils.h:130:22: note: expanded from macro 'fetch_u32' #define fetch_u32(x) __fetch(x) ^~~~~~~~~~ /home/abuild/rpmbuild/BUILD/go/src/github.com/cilium/cilium/bpf/lib/utils.h:122:21: note: expanded from macro '__fetch' # define __fetch(x) (__u32)(&(x)) ^~~~~~~~~~~~~ There are more occurrences. The warning seems valid to me: pointers on x86_64 are 64-bit wide, so the conversion to a 32-bit integer is lossy. If this is intended, convert to uintptr_t first, then to __u32: # define __fetch(x) (__u32)(uintptr_t)(&(x)) That might require #include <stdint.h>. Generally only conversions to uintptr_t are guaranteed to have no information loss, i.e. you can convert them back to a pointer and get the original pointer back. LLVM 11 is currently staged in K, so you can see the full log here: https://build.opensuse.org/package/live_build_log/openSUSE:Factory:Staging:K... -- You are receiving this mail because: You are on the CC list for the bug.
http://bugzilla.opensuse.org/show_bug.cgi?id=1178241 http://bugzilla.opensuse.org/show_bug.cgi?id=1178241#c1 --- Comment #1 from Aaron Puchert <aaronpuchert@alice-dsl.net> --- To quote C11 [1], 6.3.2.3.6:
Any pointer type may be converted to an integer type. Except as previously specified, the result is implementation-defined. If the result cannot be represented in the integer type, the behavior is undefined. The result need not be in the range of values of any integer type.
So this is warning about undefined behavior. However, 7.20.1.4 comes to the rescue:
The following type designates a signed integer type with the property that any valid pointer to void can be converted to this type, then converted back to pointer to void, and the result will compare equal to the original pointer: intptr_t The following type designates an unsigned integer type with the property that any valid pointer to void can be converted to this type, then converted back to pointer to void, and the result will compare equal to the original pointer: uintptr_t These types are optional.
[1] http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1570.pdf -- You are receiving this mail because: You are on the CC list for the bug.
http://bugzilla.opensuse.org/show_bug.cgi?id=1178241 Aaron Puchert <aaronpuchert@alice-dsl.net> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |dmueller@suse.com, | |mrostecki@suse.com -- You are receiving this mail because: You are on the CC list for the bug.
http://bugzilla.opensuse.org/show_bug.cgi?id=1178241 Michał Rostecki <mrostecki@suse.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Assignee|kubic-bugs@opensuse.org |mrostecki@suse.com -- You are receiving this mail because: You are on the CC list for the bug.
http://bugzilla.opensuse.org/show_bug.cgi?id=1178241 http://bugzilla.opensuse.org/show_bug.cgi?id=1178241#c2 Michał Rostecki <mrostecki@suse.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |IN_PROGRESS --- Comment #2 from Michał Rostecki <mrostecki@suse.com> --- Cilium doesn't use stdint.h on purpose - we don't want to have a dependency on glibc. But there is already a fix which does: # define __fetch(X) (__u32)(__u64)(&(X)) https://github.com/cilium/cilium/commit/e43c2fff3749614a0d5908df6f15db6ea96a... Let me push an update. -- You are receiving this mail because: You are on the CC list for the bug.
http://bugzilla.opensuse.org/show_bug.cgi?id=1178241 http://bugzilla.opensuse.org/show_bug.cgi?id=1178241#c3 --- Comment #3 from Michał Rostecki <mrostecki@suse.com> --- Fix here: https://build.opensuse.org/request/show/845100 -- You are receiving this mail because: You are on the CC list for the bug.
http://bugzilla.opensuse.org/show_bug.cgi?id=1178241 http://bugzilla.opensuse.org/show_bug.cgi?id=1178241#c5 Aaron Puchert <aaronpuchert@alice-dsl.net> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|RESOLVED |REOPENED Resolution|FIXED |--- --- Comment #5 from Aaron Puchert <aaronpuchert@alice-dsl.net> --- Could you bring this fix to openSUSE:Backports:SLE-15-SP3/cilium as well? It's currently broken because we updated to LLVM 11 by default (bug 1184920). -- You are receiving this mail because: You are on the CC list for the bug.
http://bugzilla.opensuse.org/show_bug.cgi?id=1178241 Aaron Puchert <aaronpuchert@alice-dsl.net> changed: What |Removed |Added ---------------------------------------------------------------------------- Blocks| |1184920 -- You are receiving this mail because: You are on the CC list for the bug.
http://bugzilla.opensuse.org/show_bug.cgi?id=1178241 http://bugzilla.opensuse.org/show_bug.cgi?id=1178241#c6 Aaron Puchert <aaronpuchert@alice-dsl.net> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|REOPENED |RESOLVED Resolution|--- |FIXED --- Comment #6 from Aaron Puchert <aaronpuchert@alice-dsl.net> --- (In reply to Aaron Puchert from comment #5)
Could you bring this fix to openSUSE:Backports:SLE-15-SP3/cilium as well?
It's currently broken because we updated to LLVM 11 by default (bug 1184920). Fixed by Max Lin via https://build.opensuse.org/request/show/887868.
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