Re: [PATCH 01/13] linux-user: Add missing signals in strace output

[Helge Deller <deller@gmx.de>]

* Richard Henderson <richard.henderson@linaro.org>:
> On 8/26/22 07:18, Helge Deller wrote:
> > +    if (arg < _NSIG)
> > +        signal_name = target_signal_to_host_signal_table[arg];

> (1) static const char * const
> (2) target_signal_name -- there's no "host" about this.

> Oh, and _NSIG is a host thing.  Leave the array as [] and then bound the
> lookup with ARRAY_SIZE(target_signal_name).  Also, missing {}.

Thanks for the review!

I've addressed your feedback in the patch below. Additionally I fixed
the indenting in the table.

All patches (including this one) is available in the git repo at:
https://github.com/hdeller/qemu-hppa/tree/publish1

Helge


From ff8e95709d2d6f9a7d8e452671aea16ed60c5114 Mon Sep 17 00:00:00 2001
From: Helge Deller <deller@gmx.de>
Date: Wed, 27 Jul 2022 16:44:05 +0200
Subject: [PATCH] linux-user: Add missing signals in strace output

Some of the guest signal numbers are currently not converted to
their representative names in the strace output, e.g. SIGVTALRM.

This patch introduces a smart way to generate and keep in sync the
host-to-guest and guest-to-host signal conversion tables for usage in
the qemu signal and strace code. This ensures that any signals
will now show up in both tables.

There is no functional change in this patch - with the exception that yet
missing signal names now show up in the strace code too.

Signed-off-by: Helge Deller <deller@gmx.de>

diff --git a/linux-user/signal-common.h b/linux-user/signal-common.h
index 6a7e4a93fc..0faf533b47 100644
--- a/linux-user/signal-common.h
+++ b/linux-user/signal-common.h
@@ -118,4 +118,50 @@ static inline void finish_sigsuspend_mask(int ret)
     }
 }

+#ifdef SIGSTKFLT
+#define MAKE_SIG_ENTRY_SIGSTKFLT        MAKE_SIG_ENTRY(SIGSTKFLT)
+#else
+#define MAKE_SIG_ENTRY_SIGSTKFLT
+#endif
+
+#ifdef SIGIOT
+#define MAKE_SIG_ENTRY_SIGIOT           MAKE_SIG_ENTRY(SIGIOT)
+#else
+#define MAKE_SIG_ENTRY_SIGIOT
+#endif
+
+#define MAKE_SIGNAL_LIST \
+        MAKE_SIG_ENTRY(SIGHUP) \
+        MAKE_SIG_ENTRY(SIGINT) \
+        MAKE_SIG_ENTRY(SIGQUIT) \
+        MAKE_SIG_ENTRY(SIGILL) \
+        MAKE_SIG_ENTRY(SIGTRAP) \
+        MAKE_SIG_ENTRY(SIGABRT) \
+        MAKE_SIG_ENTRY(SIGBUS) \
+        MAKE_SIG_ENTRY(SIGFPE) \
+        MAKE_SIG_ENTRY(SIGKILL) \
+        MAKE_SIG_ENTRY(SIGUSR1) \
+        MAKE_SIG_ENTRY(SIGSEGV) \
+        MAKE_SIG_ENTRY(SIGUSR2) \
+        MAKE_SIG_ENTRY(SIGPIPE) \
+        MAKE_SIG_ENTRY(SIGALRM) \
+        MAKE_SIG_ENTRY(SIGTERM) \
+        MAKE_SIG_ENTRY(SIGCHLD) \
+        MAKE_SIG_ENTRY(SIGCONT) \
+        MAKE_SIG_ENTRY(SIGSTOP) \
+        MAKE_SIG_ENTRY(SIGTSTP) \
+        MAKE_SIG_ENTRY(SIGTTIN) \
+        MAKE_SIG_ENTRY(SIGTTOU) \
+        MAKE_SIG_ENTRY(SIGURG) \
+        MAKE_SIG_ENTRY(SIGXCPU) \
+        MAKE_SIG_ENTRY(SIGXFSZ) \
+        MAKE_SIG_ENTRY(SIGVTALRM) \
+        MAKE_SIG_ENTRY(SIGPROF) \
+        MAKE_SIG_ENTRY(SIGWINCH) \
+        MAKE_SIG_ENTRY(SIGIO) \
+        MAKE_SIG_ENTRY(SIGPWR) \
+        MAKE_SIG_ENTRY(SIGSYS) \
+        MAKE_SIG_ENTRY_SIGSTKFLT \
+        MAKE_SIG_ENTRY_SIGIOT
+
 #endif
diff --git a/linux-user/signal.c b/linux-user/signal.c
index 8d29bfaa6b..61c6fa3fcf 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -53,40 +53,9 @@ abi_ulong default_rt_sigreturn;
 QEMU_BUILD_BUG_ON(__SIGRTMAX + 1 != _NSIG);
 #endif
 static uint8_t host_to_target_signal_table[_NSIG] = {
-    [SIGHUP] = TARGET_SIGHUP,
-    [SIGINT] = TARGET_SIGINT,
-    [SIGQUIT] = TARGET_SIGQUIT,
-    [SIGILL] = TARGET_SIGILL,
-    [SIGTRAP] = TARGET_SIGTRAP,
-    [SIGABRT] = TARGET_SIGABRT,
-/*    [SIGIOT] = TARGET_SIGIOT,*/
-    [SIGBUS] = TARGET_SIGBUS,
-    [SIGFPE] = TARGET_SIGFPE,
-    [SIGKILL] = TARGET_SIGKILL,
-    [SIGUSR1] = TARGET_SIGUSR1,
-    [SIGSEGV] = TARGET_SIGSEGV,
-    [SIGUSR2] = TARGET_SIGUSR2,
-    [SIGPIPE] = TARGET_SIGPIPE,
-    [SIGALRM] = TARGET_SIGALRM,
-    [SIGTERM] = TARGET_SIGTERM,
-#ifdef SIGSTKFLT
-    [SIGSTKFLT] = TARGET_SIGSTKFLT,
-#endif
-    [SIGCHLD] = TARGET_SIGCHLD,
-    [SIGCONT] = TARGET_SIGCONT,
-    [SIGSTOP] = TARGET_SIGSTOP,
-    [SIGTSTP] = TARGET_SIGTSTP,
-    [SIGTTIN] = TARGET_SIGTTIN,
-    [SIGTTOU] = TARGET_SIGTTOU,
-    [SIGURG] = TARGET_SIGURG,
-    [SIGXCPU] = TARGET_SIGXCPU,
-    [SIGXFSZ] = TARGET_SIGXFSZ,
-    [SIGVTALRM] = TARGET_SIGVTALRM,
-    [SIGPROF] = TARGET_SIGPROF,
-    [SIGWINCH] = TARGET_SIGWINCH,
-    [SIGIO] = TARGET_SIGIO,
-    [SIGPWR] = TARGET_SIGPWR,
-    [SIGSYS] = TARGET_SIGSYS,
+#define MAKE_SIG_ENTRY(sig)     [sig] = TARGET_##sig,
+        MAKE_SIGNAL_LIST
+#undef MAKE_SIG_ENTRY
     /* next signals stay the same */
 };

diff --git a/linux-user/strace.c b/linux-user/strace.c
index 7d882526da..ae4444a6ca 100644
--- a/linux-user/strace.c
+++ b/linux-user/strace.c
@@ -17,6 +17,7 @@
 #include "qemu.h"
 #include "user-internals.h"
 #include "strace.h"
+#include "signal-common.h"

 struct syscallname {
     int nr;
@@ -141,30 +142,21 @@ if( cmd == val ) { \
     qemu_log("%d", cmd);
 }

+static const char * const target_signal_name[] = {
+#define MAKE_SIG_ENTRY(sig)     [TARGET_##sig] = #sig,
+        MAKE_SIGNAL_LIST
+#undef MAKE_SIG_ENTRY
+};
+
 static void
 print_signal(abi_ulong arg, int last)
 {
     const char *signal_name = NULL;
-    switch(arg) {
-    case TARGET_SIGHUP: signal_name = "SIGHUP"; break;
-    case TARGET_SIGINT: signal_name = "SIGINT"; break;
-    case TARGET_SIGQUIT: signal_name = "SIGQUIT"; break;
-    case TARGET_SIGILL: signal_name = "SIGILL"; break;
-    case TARGET_SIGABRT: signal_name = "SIGABRT"; break;
-    case TARGET_SIGFPE: signal_name = "SIGFPE"; break;
-    case TARGET_SIGKILL: signal_name = "SIGKILL"; break;
-    case TARGET_SIGSEGV: signal_name = "SIGSEGV"; break;
-    case TARGET_SIGPIPE: signal_name = "SIGPIPE"; break;
-    case TARGET_SIGALRM: signal_name = "SIGALRM"; break;
-    case TARGET_SIGTERM: signal_name = "SIGTERM"; break;
-    case TARGET_SIGUSR1: signal_name = "SIGUSR1"; break;
-    case TARGET_SIGUSR2: signal_name = "SIGUSR2"; break;
-    case TARGET_SIGCHLD: signal_name = "SIGCHLD"; break;
-    case TARGET_SIGCONT: signal_name = "SIGCONT"; break;
-    case TARGET_SIGSTOP: signal_name = "SIGSTOP"; break;
-    case TARGET_SIGTTIN: signal_name = "SIGTTIN"; break;
-    case TARGET_SIGTTOU: signal_name = "SIGTTOU"; break;
+
+    if (arg < ARRAY_SIZE(target_signal_name)) {
+        signal_name = target_signal_name[arg];
     }
+
     if (signal_name == NULL) {
         print_raw_param("%ld", arg, last);
         return;