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Merge branch 'port_race_test' of github.com:redpig/lk

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edit: add a few quickie warning fixes
This commit is contained in:
Travis Geiselbrecht
2025-09-29 23:08:24 -07:00
parent 68c6ae154c 1c59a73cb4
commit f5999d5a40
2 changed files with 270 additions and 7 deletions
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34
kernel/port.c
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@@ -31,6 +31,7 @@
#define READPORT_MAGIC (0x70727472) // 'prtr'
#define PORTGROUP_MAGIC (0x70727467) // 'prtg'
#define PORTHOLD_MAGIC (0x70727467) // 'prth'
#define PORT_BUFF_SIZE 8
#define PORT_BUFF_SIZE_BIG 64
@@ -129,16 +130,24 @@ status_t port_create(const char *name, port_mode_t mode, port_t *port) {
return ERR_INVALID_ARGS;
}
if (strlen(name) >= PORT_NAME_LEN)
if (strnlen(name, PORT_NAME_LEN) >= PORT_NAME_LEN)
return ERR_INVALID_ARGS;
// Add a stack-allocated port to the list until we can
// replace it with a heap-allocated port.
write_port_t stack_wp = { .magic = PORTHOLD_MAGIC };
// We waste a few cycles here with a throwaway copy.
strlcpy(stack_wp.name, name, sizeof(stack_wp.name));
// lookup for existing port, return that if found.
write_port_t *wp = NULL;
THREAD_LOCK(state1);
list_for_every_entry(&write_port_list, wp, write_port_t, node) {
if (strcmp(wp->name, name) == 0) {
// can't return closed ports.
if (wp->magic == WRITEPORT_MAGIC_X)
// can't return closed or partial ports.
if (wp->magic == WRITEPORT_MAGIC_X ||
wp->magic == PORTHOLD_MAGIC)
wp = NULL;
THREAD_UNLOCK(state1);
if (wp) {
@@ -149,12 +158,17 @@ status_t port_create(const char *name, port_mode_t mode, port_t *port) {
}
}
}
list_add_tail(&write_port_list, &stack_wp.node);
THREAD_UNLOCK(state1);
// not found, create the write port and the circular buffer.
wp = calloc(1, sizeof(write_port_t));
if (!wp)
if (!wp) {
THREAD_LOCK(state2);
list_delete(&stack_wp.node);
THREAD_UNLOCK(state2);
return ERR_NO_MEMORY;
}
wp->magic = WRITEPORT_MAGIC_W;
wp->mode = mode;
@@ -164,13 +178,18 @@ status_t port_create(const char *name, port_mode_t mode, port_t *port) {
wp->buf = make_buf(mode & PORT_MODE_BIG_BUFFER);
if (!wp->buf) {
free(wp);
THREAD_LOCK(state2);
list_delete(&stack_wp.node);
THREAD_UNLOCK(state2);
return ERR_NO_MEMORY;
}
// todo: race condtion! a port with the same name could have been created
// by another thread at is point.
// Avoid a name collision by swapping the temporary placeholder out of the
// list for the actual port.
THREAD_LOCK(state2);
// Let's reserve a stack allocated entry then swap it for the allocated one.
list_add_tail(&write_port_list, &wp->node);
list_delete(&stack_wp.node);
THREAD_UNLOCK(state2);
*port = (void *)wp;
@@ -205,7 +224,8 @@ status_t port_open(const char *name, void *ctx, port_t *port) {
THREAD_LOCK(state);
write_port_t *wp = NULL;
list_for_every_entry(&write_port_list, wp, write_port_t, node) {
if (strcmp(wp->name, name) == 0) {
if (strcmp(wp->name, name) == 0 &&
wp->magic != PORTHOLD_MAGIC) {
// found; add read port to write port list.
rp->wport = wp;
if (wp->buf) {