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[RFC PATCH glibc 27/34] hurd: Don't leak __hurd_reply_port0
From: |
Sergey Bugaev |
Subject: |
[RFC PATCH glibc 27/34] hurd: Don't leak __hurd_reply_port0 |
Date: |
Sun, 19 Mar 2023 18:10:10 +0300 |
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>
---
sysdeps/mach/hurd/i386/tls.h | 5 +++++
sysdeps/mach/hurd/x86_64/tls.h | 9 ++++++++-
2 files changed, 13 insertions(+), 1 deletion(-)
diff --git a/sysdeps/mach/hurd/i386/tls.h b/sysdeps/mach/hurd/i386/tls.h
index ee7b8004..0ac8917a 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 da504d9c..2b7135f6 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;
}
--
2.39.2
- [RFC PATCH glibc 19/34] hurd: Move a couple of singal-related files to x86, (continued)
- [RFC PATCH glibc 19/34] hurd: Move a couple of singal-related files to x86, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 24/34] hurd: Only check for TLS initialization inside rtld or in static builds, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 21/34] x86_64: Add rtld-stpncpy & rtld-strncpy, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 23/34] elf: Stop including tls.h in ldsodefs.h, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 25/34] hurd: Improve reply port handling when exiting signal handlers, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 22/34] htl: Implement thread_set_pcsptp for x86_64, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 29/34] hurd: Add vm_param.h for x86_64, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 31/34] hurd: Microoptimize _hurd_self_sigstate (), Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 26/34] hurd: Remove __hurd_local_reply_port, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 20/34] htl: Add tcb-offsets.sym for x86_64, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 27/34] hurd: Don't leak __hurd_reply_port0,
Sergey Bugaev <=
- [RFC PATCH glibc 28/34] hurd: Implement _hurd_longjmp_thread_state for x86_64, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 30/34] hurd: Implement longjmp for x86_64, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 32/34] hurd: Implement sigreturn for x86_64, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 33/34] hurd: Create abilist files for lib{mach, hurd}user, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 34/34] hurd: Add expected abilist files for x86_64, Sergey Bugaev, 2023/03/19