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authorThomas Meyer <thomas@m3y3r.de>2015-03-28 09:59:46 +0100
committerRichard Weinberger <richard@nod.at>2015-04-13 21:17:44 +0200
commit33bbc3065414722065a20cbdbeaf352173e72f39 (patch)
treef4cf1b3df0f7a23f80a9d14129ec8f8c1f14ad19 /arch/um
parent04a418495e0852263d77c4fb82adf470feaafef3 (diff)
um: Move uml_postsetup in the init_thread stack
atomic_notifier_chain_register() and uml_postsetup() do call kernel code that rely on the "current" kernel macro and a valid task_struct resp. thread_info struct. Give those functions a valid stack by moving uml_postsetup() in the init_thread stack. This moves enables a panic() call in this early code to generate a valid stacktrace, instead of crashing. E.g. when an UML kernel is started with an initrd but too few physical memory the panic() call get's actually processed. Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'arch/um')
-rw-r--r--arch/um/include/shared/as-layout.h1
-rw-r--r--arch/um/kernel/um_arch.c15
-rw-r--r--arch/um/os-Linux/skas/process.c2
3 files changed, 12 insertions, 6 deletions
diff --git a/arch/um/include/shared/as-layout.h b/arch/um/include/shared/as-layout.h
index 41c8c774ec10..ca1843e1df15 100644
--- a/arch/um/include/shared/as-layout.h
+++ b/arch/um/include/shared/as-layout.h
@@ -56,6 +56,7 @@ extern unsigned long brk_start;
extern unsigned long host_task_size;
extern int linux_main(int argc, char **argv);
+extern void uml_finishsetup(void);
struct siginfo;
extern void (*sig_info[])(int, struct siginfo *si, struct uml_pt_regs *);
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index 926ecdceba86..07f798f4bcee 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -226,6 +226,16 @@ static struct notifier_block panic_exit_notifier = {
.priority = 0
};
+void uml_finishsetup(void)
+{
+ atomic_notifier_chain_register(&panic_notifier_list,
+ &panic_exit_notifier);
+
+ uml_postsetup();
+
+ new_thread_handler();
+}
+
/* Set during early boot */
unsigned long task_size;
EXPORT_SYMBOL(task_size);
@@ -326,11 +336,6 @@ int __init linux_main(int argc, char **argv)
printf("Kernel virtual memory size shrunk to %lu bytes\n",
virtmem_size);
- atomic_notifier_chain_register(&panic_notifier_list,
- &panic_exit_notifier);
-
- uml_postsetup();
-
stack_protections((unsigned long) &init_thread_info);
os_flush_stdout();
diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c
index 50ebeae5cbb3..7a9777570a62 100644
--- a/arch/um/os-Linux/skas/process.c
+++ b/arch/um/os-Linux/skas/process.c
@@ -586,7 +586,7 @@ int start_idle_thread(void *stack, jmp_buf *switch_buf)
n = setjmp(initial_jmpbuf);
switch (n) {
case INIT_JMP_NEW_THREAD:
- (*switch_buf)[0].JB_IP = (unsigned long) new_thread_handler;
+ (*switch_buf)[0].JB_IP = (unsigned long) uml_finishsetup;
(*switch_buf)[0].JB_SP = (unsigned long) stack +
UM_THREAD_SIZE - sizeof(void *);
break;