From 513c1cdfaaa3432dc4674a2d3be3dcaec2b4343e Mon Sep 17 00:00:00 2001
From: Jacob Lalonde <jalalonde@fb.com>
Date: Fri, 30 May 2025 14:21:33 -0700
Subject: [PATCH] [LLDB][Platform Linux] Flip uid and pid in get signal
 description (#142200)

Despite a great review from @labath, I accidentally landed the signal
with the UID and PID properties flipped. I was actually trying to write
tests for this feature when I discovered it.

This fixes that bug, and add a shell test that runs only on Nix systems.
---
 .../Plugins/Platform/Linux/PlatformLinux.cpp     |   2 +-
 lldb/test/Shell/Register/Core/Inputs/tkill.cpp   |  10 ++++++++++
 .../Register/Core/Inputs/x86-64-linux-tkill.core | Bin 0 -> 8048 bytes
 .../Shell/Register/Core/x86-64-linux-tkill.test  |   5 +++++
 4 files changed, 16 insertions(+), 1 deletion(-)
 create mode 100644 lldb/test/Shell/Register/Core/Inputs/tkill.cpp
 create mode 100644 lldb/test/Shell/Register/Core/Inputs/x86-64-linux-tkill.core
 create mode 100644 lldb/test/Shell/Register/Core/x86-64-linux-tkill.test

diff --git a/lldb/source/Plugins/Platform/Linux/PlatformLinux.cpp b/lldb/source/Plugins/Platform/Linux/PlatformLinux.cpp
index 269105208a87..da14da44f593 100644
--- a/lldb/source/Plugins/Platform/Linux/PlatformLinux.cpp
+++ b/lldb/source/Plugins/Platform/Linux/PlatformLinux.cpp
@@ -580,7 +580,7 @@ static std::string GetDescriptionFromSiginfo(lldb::ValueObjectSP siginfo_sp) {
   }
 
   return linux_signals.GetSignalDescription(signo, code, addr, lower, upper,
-                                            uid, pid);
+                                            pid, uid);
 }
 
 lldb::StopInfoSP PlatformLinux::GetStopInfoFromSiginfo(Thread &thread) {
diff --git a/lldb/test/Shell/Register/Core/Inputs/tkill.cpp b/lldb/test/Shell/Register/Core/Inputs/tkill.cpp
new file mode 100644
index 000000000000..677bd3e6cf49
--- /dev/null
+++ b/lldb/test/Shell/Register/Core/Inputs/tkill.cpp
@@ -0,0 +1,10 @@
+#include <signal.h>
+#include <sys/syscall.h>
+
+int main() {
+  // Get the current thread ID
+  pid_t tid = syscall(SYS_gettid);
+  // Send a SIGSEGV signal to the current thread
+  syscall(SYS_tkill, tid, SIGSEGV);
+  return 0;
+}
diff --git a/lldb/test/Shell/Register/Core/Inputs/x86-64-linux-tkill.core b/lldb/test/Shell/Register/Core/Inputs/x86-64-linux-tkill.core
new file mode 100644
index 0000000000000000000000000000000000000000..3d1a05a34e7ca001108fd3c45c6f68ba5d379a9a
GIT binary patch
literal 8048
zcmeHMO=w(I6h4iywfNKN!nXdPPf&@3%uHg8?Lv9Bq;X)-N7_hTO(vP3(J>h^6Dfk`
z2`(xkOqUjfSa7KhXrb=nP8Y&JH@eGCbfH0TQ47ZV^L@|vZr?DS(wb7{Lf(1j-22^g
z?zw;8o2*S1j}PqHB`kyTy!@w$_^gOYUk=L<^g-J9@+B#22a-D5Yaiy_Lw&IP?b(@R
zTcc%QgVeY?waL>DRc5apm+)7+PF(2VocJUb=WZQeUO!Z6_K5QhN@U%|4cLkdrB$PR
z2C$3&<heEU5f|arIFnD}!lUW9;2`{V@YjAd9T%G3C7u^E5A+w5k~km1Qo8wUBL1d>
z^MIptaV_9l4z3LxWejKH4DYZFf|X>PfJq9@jF>pDo{p0}wuessym!)Z8y)gVf17Jb
z9QtSeDfN0W>$8dRZCyLg<YgT=36uVqmnIH`*!WE3#5F%m$87)*!zKI$=hAWc4*8_N
z@UtYYjX)`5{!CtK#;ZthK8Zs+=8-bWX9(P^gUiDorR%Q+-1-+ue?D-OF`Pkc0k`Sk
z0E^C_7|zTCahWfZ{)qGRh*XK;68`dErQ`Az))6=B;LtzYQ%3o;r@ct6M_dN`By?~d
z;-hrOmj}*kCCBFjM;XHzL=CuE2S-1YF`UU~lW{sYxRVr|K@hjz0av^FoKN`6e4QL0
z{k8DYDb5WC$M`5?IJ1vh7~f`(xHfQG?|tx3{2uc#F3OlcvtqY!4#@1bE*uuul`FNE
zKmj%O*vr$Cy8Yeyff9eG?b3xIdE&wWp`_iF7t_FQBdsGh7eBUly<fKS)E}W4yZ^hD
zgziBKHrjUXzuT{9f|^`Pw)^qzz|1iv!_jf;@;w@|{%Pp!e+YhuVV8D?Glun!H1nZs
zI>%?!pT04eW0_WpF1vjr4*j-QD(a0nrEI*pSgmH4R~x34NUl<Dlyj@~g_U~ljdHbI
zU0$jz<m%<6N~y6>Z<OYjl^TIOpgId3Td4jDQ-u?Zjd}VT>qp0;<NLpgj;W@Sr}qzI
zdW_C-zHqMc_u2|<1KGavks)ek@98R3s3l^G&ap1My?yZRL2Fjb-WDB$F6f?YMJ3Cw
zxw~w2^kjAd@NwpldAkQKsk2|kb06xdgKb9rKY+Ji|FnDILFm{D@+kBl_PuZR%s%Ls
z(f%Rm4?EI>?g~Brvnq*`#lmsU!6R(MWb>QF{RW|qZw&4Ofi9ul-;A9)zY!vP6Wo8@
zO3s=3Dzj&|%hjoai`!kUf+jZy*Z!0Nk$Zzn|3y1=X<4p(nRaqum(x-QXXV@qIV?Eo
zyUZUsDmdp)v_~A&a>}1+C&zR-BXw}XPuQLu5uERH#!n6iPIr)rCdUJ3dz^N1DwiWs
z2M3Dgg`5Z+=YGaR&I1l}h<0)sa1^d_?lE!icIvph8K&?q$KCuC`{!Ma`(>PV=px^k
zbu<BcZ)a<dNAWGze6_xkt1iw>jO*uow!WO55OuBGWaC?Dj&6pr-l)tE4;ydUe0J=J
zGq#<qer<lfR38}~9U04yjpv^oJ))x=bppKg8dXNBi%YAgM@}D}7?~K?F^?r;-idm(
zZ_Pce4g!4^@Sa+W4kT`PD?@cjZf{4YMzV4THAB?-P;pEZ3rCNYg6YC5FPxl|Qb}uL
zD%~vEXV63$)wZ3Yy)SJBH1|8B2-$#|>SE!gnNv#duZi1hb^OxfHa_2D``as9H()dw
z`z1AKzGQDefBi1{8R#Jcxh|!LuCA+Tw{L@Pop$@xrW-!~tB#y_ak5x^E;qNhl$$Hp
YUsuGZ*bU#W?`L2qGjMWd#{75tU*eM_V*mgE

literal 0
HcmV?d00001

diff --git a/lldb/test/Shell/Register/Core/x86-64-linux-tkill.test b/lldb/test/Shell/Register/Core/x86-64-linux-tkill.test
new file mode 100644
index 000000000000..64b99af2d83f
--- /dev/null
+++ b/lldb/test/Shell/Register/Core/x86-64-linux-tkill.test
@@ -0,0 +1,5 @@
+# REQUIRES: system-linux
+# RUN: %lldb -b -s %s -c %p/Inputs/x86-64-linux-tkill.core | FileCheck %s
+
+thread list
+# CHECK: hread #1: tid = 2667987, 0x00007f9a265076cd, name = 'tkill.out', stop reason = SIGSEGV: sent by tkill system call (sender pid=2667987, uid=649752)