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hurd: Don't leak __hurd_reply_port0

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Previously, once we set up TLS, we would implicitly switch from using
__hurd_reply_port0 to reply_port inside the TCB, leaving the former
unused. But we never deallocated it, so it got leaked.

Instead, migrate the port into the new TCB's reply_port slot. This
avoids both the port leak and an extra syscall to create a new reply
port for the TCB.

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230319151017.531737-28-bugaevc@gmail.com>
This commit is contained in:
Sergey Bugaev 2023-03-19 18:10:10 +03:00 committed by Samuel Thibault
parent 747812349d
commit cd019ddd89
2 changed files with 13 additions and 1 deletions
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5
sysdeps/mach/hurd/i386/tls.h
View File

@ -141,12 +141,15 @@ _hurd_tls_init (tcbhead_t *tcb)
HURD_TLS_DESC_DECL (desc, tcb); HURD_TLS_DESC_DECL (desc, tcb);
thread_t self = __mach_thread_self (); thread_t self = __mach_thread_self ();
bool success = true; bool success = true;
extern mach_port_t __hurd_reply_port0;
/* This field is used by TLS accesses to get our "thread pointer" /* This field is used by TLS accesses to get our "thread pointer"
from the TLS point of view. */ from the TLS point of view. */
tcb->tcb = tcb; tcb->tcb = tcb;
/* We always at least start the sigthread anyway. */ /* We always at least start the sigthread anyway. */
tcb->multiple_threads = 1; tcb->multiple_threads = 1;
/* Take over the reply port we've been using. */
tcb->reply_port = __hurd_reply_port0;
/* Get the first available selector. */ /* Get the first available selector. */
int sel = -1; int sel = -1;
@ -172,6 +175,8 @@ _hurd_tls_init (tcbhead_t *tcb)
/* Now install the new selector. */ /* Now install the new selector. */
asm volatile ("mov %w0, %%gs" :: "q" (sel)); asm volatile ("mov %w0, %%gs" :: "q" (sel));
/* This port is now owned by the TCB. */
__hurd_reply_port0 = MACH_PORT_NULL;
out: out:
__mach_port_deallocate (__mach_task_self (), self); __mach_port_deallocate (__mach_task_self (), self);

7
sysdeps/mach/hurd/x86_64/tls.h
View File

@ -177,13 +177,20 @@ _hurd_tls_init (tcbhead_t *tcb)
{ {
error_t err; error_t err;
thread_t self = __mach_thread_self (); thread_t self = __mach_thread_self ();
extern mach_port_t __hurd_reply_port0;
/* We always at least start the sigthread anyway. */ /* We always at least start the sigthread anyway. */
tcb->multiple_threads = 1; tcb->multiple_threads = 1;
/* Take over the reply port we've been using. */
tcb->reply_port = __hurd_reply_port0;
err = _hurd_tls_new (self, tcb); err = _hurd_tls_new (self, tcb);
if (err == 0) if (err == 0)
{
__libc_tls_initialized = 1; __libc_tls_initialized = 1;
/* This port is now owned by the TCB. */
__hurd_reply_port0 = MACH_PORT_NULL;
}
__mach_port_deallocate (__mach_task_self (), self); __mach_port_deallocate (__mach_task_self (), self);
return err == 0; return err == 0;
} }