restructure results

1 files changed, 26 insertions, 0 deletions

diff --git a/results/classifier/zero-shot-user-mode/syscall/1361 b/results/classifier/zero-shot-user-mode/syscall/1361
new file mode 100644
index 00000000..bbc28d13
--- /dev/null
+++ b/results/classifier/zero-shot-user-mode/syscall/1361
@@ -0,0 +1,26 @@
+syscall: 0.432
+instruction: 0.356
+runtime: 0.212
+
+
+
+ppc64le linux user emulation w/ 64KiB pages seems broken since v5.0.0
+Description of problem:
+[Our (snmalloc's)](https://github.com/microsoft/snmalloc) CI includes running a PowerPC64 little-endian Linux build inside qemu, running with 64KiB pages as, at least, Debian runs them by default.  As reported [over there](https://github.com/microsoft/snmalloc/issues/576), this broke when GitHub's CI runners moved from Ubuntu Focal (20.04) to Jammy (22.04), bringing qemu from v4.2 to v6.2.
+
+The failing test case appears to die of an erroneous `SIGSEGV` `SEGV_MAPERR`:
+```
+--- SIGSEGV {si_signo=SIGSEGV, si_code=1, si_addr=0x0000004001be5000} ---
+```
+despite that address nominally being mapped by the last memory syscall to touch that area
+```
+openat(AT_FDCWD,"/usr/powerpc64le-linux-gnu/lib/libstdc++.so.6",O_RDONLY|O_CLOEXEC) = 4
+[...]
+mmap(0x0000004001bd0000,131072,PROT_READ|PROT_WRITE,MAP_PRIVATE|MAP_DENYWRITE|MAP_FIXED,4,0x2f0000) = 0x4001bd0000
+```
+
+Bisection reveals that the breakage first occurred with 4dcf078f094d436866ef793aa25c96fba85ac8d0, though I suspect this is merely the commit that exposes some underlying bug rather than being the actual root cause.
+Steps to reproduce:
+Run a ppc64el Linux executable under `qemu-user` with `-p 65536`.
+Additional information:
+Please advise what more would be useful.