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-rw-r--r--com32/elflink/ldlinux/execute.c4
-rw-r--r--com32/elflink/ldlinux/ldlinux.c28
-rw-r--r--core/elflink/load_env32.c58
3 files changed, 80 insertions, 10 deletions
diff --git a/com32/elflink/ldlinux/execute.c b/com32/elflink/ldlinux/execute.c
index 653c880d..39555715 100644
--- a/com32/elflink/ldlinux/execute.c
+++ b/com32/elflink/ldlinux/execute.c
@@ -44,6 +44,7 @@ const struct image_types image_boot_types[] = {
{ NULL, 0 },
};
+extern jmp_buf __return_to_command_prompt;
extern int create_args_and_load(char *);
__export void execute(const char *cmdline, uint32_t type, bool sysappend)
@@ -136,7 +137,8 @@ __export void execute(const char *cmdline, uint32_t type, bool sysappend)
/* Restore the console */
ldlinux_console_init();
- ldlinux_enter_command();
+ /* Jump back to the main to call ldlinux_enter_command */
+ longjmp(__return_to_command_prompt, 1);
} else if (type == IMAGE_TYPE_CONFIG) {
char *argv[] = { LDLINUX, NULL, NULL };
char *config;
diff --git a/com32/elflink/ldlinux/ldlinux.c b/com32/elflink/ldlinux/ldlinux.c
index 9b01dd3a..0172117b 100644
--- a/com32/elflink/ldlinux/ldlinux.c
+++ b/com32/elflink/ldlinux/ldlinux.c
@@ -31,6 +31,8 @@ static const struct file_ext file_extensions[] = {
{ NULL, 0 },
};
+jmp_buf __return_to_command_prompt;
+
/*
* Return a pointer to one byte after the last character of the
* command.
@@ -302,6 +304,7 @@ __export int main(int argc __unused, char **argv)
const void *adv;
const char *cmdline;
size_t count = 0;
+ int retval;
ldlinux_console_init();
@@ -333,16 +336,25 @@ __export int main(int argc __unused, char **argv)
if (!syslinux_setadv(ADV_BOOTONCE, 0, NULL))
syslinux_adv_write();
- load_kernel(cmdline); /* Shouldn't return */
- ldlinux_enter_command();
- }
-
- if (!forceprompt && !shift_is_held())
- ldlinux_auto_boot();
+ /*
+ * The corresponding longjmp is located in the execute function
+ * after a COM32 module has returned.
+ */
+ retval = setjmp(__return_to_command_prompt);
+ if (retval == 0)
+ load_kernel(cmdline); /* Shouldn't return */
+ } else {
+ retval = setjmp(__return_to_command_prompt);
+ if (retval == 0) {
+ if (!forceprompt && !shift_is_held())
+ ldlinux_auto_boot();
- if (defaultlevel > 1)
- ldlinux_auto_boot();
+ if (defaultlevel > 1)
+ ldlinux_auto_boot();
+ }
+ }
+ retval = setjmp(__return_to_command_prompt);
ldlinux_enter_command();
return 0;
}
diff --git a/core/elflink/load_env32.c b/core/elflink/load_env32.c
index 492cc095..db19c7aa 100644
--- a/core/elflink/load_env32.c
+++ b/core/elflink/load_env32.c
@@ -55,7 +55,7 @@ void init_module_subsystem(struct elf_module *module)
list_add(&module->list, &modules_head);
}
-__export int start_ldlinux(int argc, char **argv)
+static int _start_ldlinux(int argc, char **argv)
{
int rv;
@@ -96,6 +96,62 @@ again:
return rv;
}
+__export int start_ldlinux(int argc, char **argv)
+{
+ /* These variables are static to survive the longjmp. */
+ static int has_jmpbuf = 0;
+ static jmp_buf restart;
+ static int savedargc;
+ static char *heapargs;
+ static size_t argsmem = 0;
+ char **stackargv;
+ char *stackargs;
+ char *p, *q;
+ int i;
+
+
+ /* 1. Save the arguments on the heap */
+ for (i = 0; i < argc; i++)
+ argsmem += strlen(argv[i]) + 1;
+
+ savedargc = argc;
+ heapargs = malloc(argsmem);
+
+ p = heapargs;
+ for (i = 0; i < savedargc; i++) {
+ q = argv[i];
+ while (*q)
+ *p++ = *q++;
+
+ *p++ = '\0';
+ }
+
+ /* 2. Undo the stack if we're restarting ldlinux */
+ if (has_jmpbuf)
+ longjmp(restart, 1);
+
+ setjmp(restart);
+ has_jmpbuf = 1;
+
+ /* 3. Convert the heap memory to stack memory to avoid memory leaks */
+ stackargs = alloca(argsmem);
+ stackargv = alloca(savedargc * (sizeof(char *) + 1));
+
+ memcpy(stackargs, heapargs, argsmem);
+
+ p = stackargs;
+ for (i = 0; i < savedargc; i++) {
+ stackargv[i] = p;
+ p += strlen(p) + 1;
+ }
+
+ stackargv[savedargc] = NULL;
+
+ free(heapargs);
+
+ return _start_ldlinux(savedargc, stackargv);
+}
+
/* note to self: do _*NOT*_ use static key word on this function */
void load_env32(com32sys_t * regs __unused)
{