(nuttx) branch master updated: sched/sem_holder.c: When accessing SEM_WAITLIST, use holder's addrenv

[xi...@apache.org]

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xiaoxiang pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/nuttx.git


The following commit(s) were added to refs/heads/master by this push:
     new b7b0a17682 sched/sem_holder.c: When accessing SEM_WAITLIST, use holder's addrenv
b7b0a17682 is described below

commit b7b0a176825e58f691beb54eb78b7c780c5e67b9
Author: Ville Juven <vi...@unikie.com>
AuthorDate: Wed Nov 15 10:49:14 2023 +0200

    sched/sem_holder.c: When accessing SEM_WAITLIST, use holder's addrenv
    
    If the semaphore is shared, the holder has put its own mmapped address
    to pholder->sem. This means we must switch to the holder's address
    environment when going through the held semaphores list.
    
    A better option would be to get the kernel mapped address for the
    semaphore's physical page, but that mechanism is not functional yet.
    
    This fixes a full system crash when CONFIG_PRIORITY_INHERITANCE=y and
    CONFIG_BUILD_KERNEL=y and user makes shared semaphore via:
    
    int semfd  = shm_open("sem", O_CREAT | O_RDWR, 0666);
    sem_t *sem = mmap(0, sizeof(sem_t), PROT_READ | PROT_WRITE, MAP_SHARED, semfd, 0);
---
 sched/semaphore/sem_holder.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/sched/semaphore/sem_holder.c b/sched/semaphore/sem_holder.c
index 157e9e86d1..e16ed27e4e 100644
--- a/sched/semaphore/sem_holder.c
+++ b/sched/semaphore/sem_holder.c
@@ -27,6 +27,8 @@
 #include <sched.h>
 #include <assert.h>
 #include <debug.h>
+
+#include <nuttx/addrenv.h>
 #include <nuttx/arch.h>
 
 #include "sched/sched.h"
@@ -400,6 +402,15 @@ static void nxsem_restore_priority(FAR struct tcb_s *htcb)
     {
       FAR struct semholder_s *pholder;
 
+#ifdef CONFIG_ARCH_ADDRENV
+      FAR struct addrenv_s *oldenv;
+
+      if (htcb->addrenv_own)
+        {
+          addrenv_select(htcb->addrenv_own, &oldenv);
+        }
+#endif
+
       /* Try to find the highest priority across all the threads that are
        * waiting for any semaphore held by htcb.
        */
@@ -417,6 +428,13 @@ static void nxsem_restore_priority(FAR struct tcb_s *htcb)
             }
         }
 
+#ifdef CONFIG_ARCH_ADDRENV
+      if (htcb->addrenv_own)
+        {
+          addrenv_restore(oldenv);
+        }
+#endif
+
       /* Apply the selected priority to the thread (hopefully back to the
        * threads base_priority).
        */