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Revert change releasing option buffers by idle task - not safe
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@ghaerr
ghaerr committed Nov 13, 2024
1 parent 8ac4340 commit f5c159c
Showing 1 changed file with 50 additions and 52 deletions.
102 changes: 50 additions & 52 deletions elks/init/main.c
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Original file line number Diff line number Diff line change
Expand Up @@ -65,21 +65,27 @@ char errmsg_initargs[] = "init args > " STR(MAX_INIT_ARGS) "\n";
char errmsg_initenvs[] = "init envs > " STR(MAX_INIT_ENVS) "\n";
char errmsg_initslen[] = "init words > " STR(MAX_INIT_SLEN) "\n";

#ifdef CONFIG_SYS_NO_BININIT
static char *argv_init[MAX_INIT_SLEN] = { NULL, binshell, NULL };
#else
/* argv_init doubles as sptr data for sys_execv later*/
static char *argv_init[MAX_INIT_SLEN] = { NULL, bininit, NULL };
#endif
static char hasopts;
static int args = 2; /* room for argc and av[0] */
static int envs;
static int argv_slen;
#if ENV
static char *envp_init[MAX_INIT_ENVS];
#endif

/* this entire structure is released to kernel heap after /bootopts parsing */
static struct {
int hasopts;
int args;
int envs;
int argv_slen;
char *argv_init[MAX_INIT_SLEN]; /* argv_init doubles as sptr data for sys_execv */
struct umbseg { /* save umb= lines during /bootopts parse */
struct umbseg { /* save umb= lines during /bootopts parse */
seg_t base;
segext_t len;
} umbseg[MAX_UMB], *nextumb;
unsigned char options[OPTSEGSZ];
#if ENV
char *envp_init[MAX_INIT_ENVS];
#endif
unsigned char options[OPTSEGSZ]; /* near data parsing buffer */
} opts;

extern int boot_rootdev;
Expand Down Expand Up @@ -111,15 +117,6 @@ void start_kernel(void)
kfork_proc(init_task);
wake_up_process(&task[1]);

#ifdef CONFIG_BOOTOPTS
/* Release /bootopts load segment (DEF_OPTSEG) and setup data segment (REL_INITSEG) */
seg_add(DEF_OPTSEG, DMASEG);

/* Let init_task run, then release kernel data associated with /bootopts parsing */
schedule();
heap_add(&opts, sizeof(opts));
#endif

/*
* We are now the idle task. We won't run unless no other process can run.
* The idle task always runs with _gint_count == 1 (switched from user mode syscall)
Expand All @@ -129,7 +126,7 @@ void start_kernel(void)
#ifdef CONFIG_TIMER_INT0F
int0F(); /* simulate timer interrupt hooked on IRQ 7 */
#else
idle_halt(); /* halt until interrupt to save power */
idle_halt(); /* halt until interrupt to save poer */
#endif
}
}
Expand All @@ -146,9 +143,7 @@ static void INITPROC early_kernel_init(void)
ROOT_DEV = SETUP_ROOT_DEV; /* default root device from boot loader */
#ifdef CONFIG_BOOTOPTS
opts.nextumb = opts.umbseg; /* init static structure variables */
opts.args = 2; /* room for argc and av[0] */
opts.argv_init[1] = init_command;
opts.hasopts = parse_options(); /* parse options found in /bootops */
hasopts = parse_options(); /* parse options found in /bootops */
#endif

/* create near heap at end of kernel bss */
Expand Down Expand Up @@ -200,7 +195,7 @@ static void INITPROC kernel_init(void)

#ifdef CONFIG_BOOTOPTS
finalize_options();
if (!opts.hasopts) printk("/bootopts not found or bad format/size\n");
if (!hasopts) printk("/bootopts not found or bad format/size\n");
#endif

#ifdef CONFIG_FARTEXT_KERNEL
Expand Down Expand Up @@ -276,16 +271,19 @@ static void INITPROC do_init_task(void)
sys_dup(num); /* open stderr*/
//}


#ifdef CONFIG_BOOTOPTS
/* Release options parsing buffers and setup data seg */
heap_add(&opts, sizeof(opts));
seg_add(DEF_OPTSEG, DMASEG); /* DEF_OPTSEG through REL_INITSEG */

/* pass argc/argv/env array to init_command */

/* unset special sys_wait4() processing if pid 1 not /bin/init*/
if (strcmp(init_command, bininit) != 0)
current->ppid = 1; /* turns off auto-child reaping*/

/* run /bin/init or init= command, normally no return*/
run_init_process_sptr(init_command, (char *)opts.argv_init, opts.argv_slen);
run_init_process_sptr(init_command, (char *)argv_init, argv_slen);
#else
try_exec_process(init_command);
#endif /* CONFIG_BOOTOPTS */
Expand Down Expand Up @@ -512,7 +510,7 @@ static int INITPROC parse_options(void)
}
if (!strncmp(line,"init=",5)) {
line += 5;
init_command = opts.argv_init[1] = line;
init_command = argv_init[1] = line;
continue;
}
if (!strncmp(line,"ne0=",4)) {
Expand Down Expand Up @@ -576,14 +574,14 @@ static int INITPROC parse_options(void)
* Then check if it's an environment variable or an init argument.
*/
if (!strchr(line,'=')) { /* no '=' means init argument*/
if (opts.args < MAX_INIT_ARGS)
opts.argv_init[opts.args++] = line;
if (args < MAX_INIT_ARGS)
argv_init[args++] = line;
else printk(errmsg_initargs);
}
#if ENV
else {
if (opts.envs < MAX_INIT_ENVS)
opts.envp_init[opts.envs++] = line;
if (envs < MAX_INIT_ENVS)
envp_init[envs++] = line;
else printk(errmsg_initenvs);
}
#endif
Expand All @@ -598,54 +596,54 @@ static void INITPROC finalize_options(void)

#if ENV
/* set ROOTDEV environment variable for rc.sys fsck*/
if (opts.envs + running_qemu < MAX_INIT_ENVS) {
opts.envp_init[opts.envs++] = root_dev_name(ROOT_DEV);
if (envs + running_qemu < MAX_INIT_ENVS) {
envp_init[envs++] = root_dev_name(ROOT_DEV);
if (running_qemu)
opts.envp_init[opts.envs++] = (char *)"QEMU=1";
envp_init[envs++] = (char *)"QEMU=1";
} else printk(errmsg_initenvs);
#endif

#if DEBUG
printk("args: ");
for (i=1; i<opts.args; i++)
printk("'%s'", opts.argv_init[i]);
for (i=1; i<args; i++)
printk("'%s'", argv_init[i]);
printk("\n");

#if ENV
printk("envp: ");
for (i=0; i<opts.envs; i++)
printk("'%s'", opts.envp_init[i]);
for (i=0; i<envs; i++)
printk("'%s'", envp_init[i]);
printk("\n");
#endif
#endif

/* convert argv array to stack array for sys_execv*/
opts.args--;
opts.argv_init[0] = (char *)opts.args; /* 0 = argc*/
char *q = (char *)&opts.argv_init[opts.args+2+opts.envs+1];
for (i=1; i<=opts.args; i++) { /* 1..argc = av*/
char *p = opts.argv_init[i];
args--;
argv_init[0] = (char *)args; /* 0 = argc*/
char *q = (char *)&argv_init[args+2+envs+1];
for (i=1; i<=args; i++) { /* 1..argc = av*/
char *p = argv_init[i];
char *savq = q;
while ((*q++ = *p++) != 0)
;
opts.argv_init[i] = (char *)(savq - (char *)opts.argv_init);
argv_init[i] = (char *)(savq - (char *)argv_init);
}
/*opts.argv_init[opts.args+1] = NULL;*/ /* argc+1 = 0*/
/*argv_init[args+1] = NULL;*/ /* argc+1 = 0*/
#if ENV
if (opts.envs) {
for (i=0; i<opts.envs; i++) {
char *p = opts.envp_init[i];
if (envs) {
for (i=0; i<envs; i++) {
char *p = envp_init[i];
char *savq = q;
while ((*q++ = *p++) != 0)
;
opts.argv_init[opts.args+2+i] = (char *)(savq - (char *)opts.argv_init);
argv_init[args+2+i] = (char *)(savq - (char *)argv_init);
}

}
#endif
/*opts.argv_init[opts.args+2+opts.envs] = NULL;*/
opts.argv_slen = q - (char *)opts.argv_init;
if (opts.argv_slen > sizeof(opts.argv_init))
/*argv_init[args+2+envs] = NULL;*/
argv_slen = q - (char *)argv_init;
if (argv_slen > sizeof(argv_init))
panic(errmsg_initslen);
}

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