From 657585026a375d2cb2d06ab400f9deb487d89a17 Mon Sep 17 00:00:00 2001
From: dzwdz
Date: Sat, 17 Jun 2023 17:53:23 +0200
Subject: libc: expand psdata into a proper struct, include executable base
this is very useful for debugging userland programs using the qemu gdb stub
---
src/user/lib/_start2.c | 17 +++++++----------
src/user/lib/include/_proc.h | 17 ++++++++++++-----
src/user/lib/stdlib.c | 8 +++++---
3 files changed, 24 insertions(+), 18 deletions(-)
(limited to 'src/user/lib')
diff --git a/src/user/lib/_start2.c b/src/user/lib/_start2.c
index f55feab..b4eb76a 100644
--- a/src/user/lib/_start2.c
+++ b/src/user/lib/_start2.c
@@ -26,20 +26,17 @@ _Noreturn void _start2(struct execdata *ed) {
elf_selfreloc();
/* done first so it isn't allocated elsewhere by accident */
- _sys_memflag(_libc_psdata, 1, MEMFLAG_PRESENT);
- if (ed->argv[0]) {
- strcpy(_libc_psdata, ed->argv[0]);
- } else {
- strcpy(_libc_psdata, "?");
- }
+ _sys_memflag(_psdata_loc, 1, MEMFLAG_PRESENT);
+ _psdata_loc->base = __executable_start;
+ /* sets ->desc */
+ progname = shortname(ed->argv[0]);
+ setprogname(progname);
+
+ _klogf("_start2 %s %p", progname, __executable_start);
_sys_intr_set(intr_trampoline);
intr_set(intr_default);
__setinitialcwd(ed->cwd);
- progname = shortname(ed->argv[0]);
- setprogname(progname);
- _klogf("_start2 %s %p", progname, __executable_start);
-
exit(main(ed->argc, ed->argv, ed->envp));
}
diff --git a/src/user/lib/include/_proc.h b/src/user/lib/include/_proc.h
index c8fd70b..5f9c321 100644
--- a/src/user/lib/include/_proc.h
+++ b/src/user/lib/include/_proc.h
@@ -1,7 +1,14 @@
#pragma once
-/* That page contains a null-terminated string that describes the process
- * for tools such as ps. It's first allocated in the bootstrap process, and
- * then it's freed on every exec() - just to be immediately reallocated by
- * _start2(). */
-static char *const _libc_psdata = (void*)0x10000;
+struct _psdata {
+ /* Description of the process, see setprogname.
+ * Assumed to be null terminated. */
+ char desc[1024];
+
+ /* Base offset where the executable was loaded. */
+ void *base;
+};
+
+/* First allocated in bootstrap.
+ * Freed on every exec(), just to be immediately reallocated by _start2(). */
+static struct _psdata *const _psdata_loc = (void*)0x10000;
diff --git a/src/user/lib/stdlib.c b/src/user/lib/stdlib.c
index 13745d1..1739230 100644
--- a/src/user/lib/stdlib.c
+++ b/src/user/lib/stdlib.c
@@ -16,18 +16,20 @@ const char *getprogname(void) {
}
void setprogname(const char *pg) {
progname = pg;
+ setproctitle(NULL);
}
void setproctitle(const char *fmt, ...) {
+ // TODO bounds checking
if (!fmt) {
- strcpy(_libc_psdata, progname);
+ strcpy(_psdata_loc->desc, progname);
return;
}
- sprintf(_libc_psdata, "%s: ", progname);
+ sprintf(_psdata_loc->desc, "%s: ", progname);
va_list argp;
va_start(argp, fmt);
- vsnprintf(_libc_psdata + strlen(_libc_psdata), 128, fmt, argp);
+ vsnprintf(_psdata_loc->desc + strlen(_psdata_loc->desc), 128, fmt, argp);
va_end(argp);
}
--
cgit v1.2.3