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| author | Sergey Bugaev <bugaevc@gmail.com> | 2023-03-19 18:10:10 +0300 |
|---|---|---|
| committer | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2023-04-11 00:24:40 +0200 |
| commit | cd019ddd892e182277fadd6aedccc57fa3923c8d (patch) | |
| tree | cfcc71948e40bd484e00e3105153ec305e6b19a8 | |
| parent | 747812349d42427c835aeac987aa67641d84f1ad (diff) | |
| download | glibc-cd019ddd892e182277fadd6aedccc57fa3923c8d.tar.gz glibc-cd019ddd892e182277fadd6aedccc57fa3923c8d.tar.xz glibc-cd019ddd892e182277fadd6aedccc57fa3923c8d.zip | |
hurd: Don't leak __hurd_reply_port0
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>
| -rw-r--r-- | sysdeps/mach/hurd/i386/tls.h | 5 | ||||
| -rw-r--r-- | sysdeps/mach/hurd/x86_64/tls.h | 9 |
2 files changed, 13 insertions, 1 deletions
diff --git a/sysdeps/mach/hurd/i386/tls.h b/sysdeps/mach/hurd/i386/tls.h index ee7b8004bc..0ac8917a95 100644 --- a/sysdeps/mach/hurd/i386/tls.h +++ b/sysdeps/mach/hurd/i386/tls.h @@ -141,12 +141,15 @@ _hurd_tls_init (tcbhead_t *tcb) HURD_TLS_DESC_DECL (desc, tcb); thread_t self = __mach_thread_self (); bool success = true; + extern mach_port_t __hurd_reply_port0; /* This field is used by TLS accesses to get our "thread pointer" from the TLS point of view. */ tcb->tcb = tcb; /* We always at least start the sigthread anyway. */ tcb->multiple_threads = 1; + /* Take over the reply port we've been using. */ + tcb->reply_port = __hurd_reply_port0; /* Get the first available selector. */ int sel = -1; @@ -172,6 +175,8 @@ _hurd_tls_init (tcbhead_t *tcb) /* Now install the new selector. */ asm volatile ("mov %w0, %%gs" :: "q" (sel)); + /* This port is now owned by the TCB. */ + __hurd_reply_port0 = MACH_PORT_NULL; out: __mach_port_deallocate (__mach_task_self (), self); diff --git a/sysdeps/mach/hurd/x86_64/tls.h b/sysdeps/mach/hurd/x86_64/tls.h index da504d9c81..2b7135f635 100644 --- a/sysdeps/mach/hurd/x86_64/tls.h +++ b/sysdeps/mach/hurd/x86_64/tls.h @@ -177,13 +177,20 @@ _hurd_tls_init (tcbhead_t *tcb) { error_t err; thread_t self = __mach_thread_self (); + extern mach_port_t __hurd_reply_port0; /* We always at least start the sigthread anyway. */ 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); 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); return err == 0; } |