Eric Lee / smarc-fsl-linux-kernel

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Commit dae3c5a0b7052ad7dd9fa78c51ecfab828c5007b

Authored by Oleg Nesterov
Committed by Linus Torvalds
1 parent ae424ae4b5
Exists in master and in 39 other branches 8mp-imx_5.4.70_2.3.0, 8qm-imx_5.4.70_2.3.0, emb_imx_lf-5.15.y, emb_lf-6.1.y, imx_3.0.35_4.1.0, imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, imx_4.1.15_1.0.0_ga, pitx_8mp_lf-5.10.y, rt-smarc-imx_4.1.15_1.0.0_ga, rt_linux_5.15.71, smarc-8m-android-11.0.0_2.0.0, smarc-imx6_4.14.98_2.0.0_ga, smarc-imx6_4.9.88_2.0.0_ga, smarc-imx7_4.14.98_2.0.0_ga, smarc-imx7_4.9.11_1.0.0_ga, smarc-imx7_4.9.88_2.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-imx_4.1.15_1.0.0_ga, smarc-imx_4.9.11_1.0.0_ga, smarc-imx_4.9.51_imx8m_ga, smarc-imx_4.9.88_2.0.0_ga, smarc-m6.0.1_2.1.0-ga, smarc-n7.1.2_2.0.0-ga, smarc-rel_imx_4.1.15_1.2.0_ga, smarc_8m_00d0_imx_4.14.98_2.0.0_ga, smarc_8m_imx_4.14.78_1.0.0_ga, smarc_8m_imx_4.14.98_2.0.0_ga, smarc_8m_imx_4.19.35_1.1.0, smarc_8mm_imx_4.14.78_1.0.0_ga, smarc_8mm_imx_4.14.98_2.0.0_ga, smarc_8mm_imx_4.19.35_1.1.0, smarc_8mm_imx_5.4.24_2.1.0, smarc_8mp_lf-5.10.y, smarc_8mq_imx_5.4.24_2.1.0, smarc_8mq_lf-5.10.y, smarc_imx_lf-5.15.y

[PATCH] sys_unshare: remove a broken CLONE_SIGHAND code 

sys_unshare(CLONE_SIGHAND) is broken, the code under 'if (new_sigh)' is
never executed but very wrong. Just remove it to avoid a confusion,
task_lock() has nothing to do with ->sighand changing.

Also, change the comment in unshare_sighand(). Yes, CLONE_THREAD implies
CLONE_SIGHAND, but still it looks confusing. Also, we don't need to check
current->sighand != NULL.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Showing 1 changed file with 4 additions and 12 deletions Side-by-side Diff

... ... @@ -1544,15 +1544,13 @@
1544 1544 }
1545 1545  
1546 1546 /*
1547   - * Unsharing of sighand for tasks created with CLONE_SIGHAND is not
1548   - * supported yet
  1547 + * Unsharing of sighand is not supported yet
1549 1548 */
1550 1549 static int unshare_sighand(unsigned long unshare_flags, struct sighand_struct **new_sighp)
1551 1550 {
1552 1551 struct sighand_struct *sigh = current->sighand;
1553 1552  
1554   - if ((unshare_flags & CLONE_SIGHAND) &&
1555   - (sigh && atomic_read(&sigh->count) > 1))
  1553 + if ((unshare_flags & CLONE_SIGHAND) && atomic_read(&sigh->count) > 1)
1556 1554 return -EINVAL;
1557 1555 else
1558 1556 return 0;
... ... @@ -1626,7 +1624,7 @@
1626 1624 int err = 0;
1627 1625 struct fs_struct *fs, *new_fs = NULL;
1628 1626 struct namespace *ns, *new_ns = NULL;
1629   - struct sighand_struct *sigh, *new_sigh = NULL;
  1627 + struct sighand_struct *new_sigh = NULL;
1630 1628 struct mm_struct *mm, *new_mm = NULL, *active_mm = NULL;
1631 1629 struct files_struct *fd, *new_fd = NULL;
1632 1630 struct sem_undo_list *new_ulist = NULL;
... ... @@ -1671,7 +1669,7 @@
1671 1669 }
1672 1670 }
1673 1671  
1674   - if (new_fs || new_ns || new_sigh || new_mm || new_fd || new_ulist ||
  1672 + if (new_fs || new_ns || new_mm || new_fd || new_ulist ||
1675 1673 new_uts || new_ipc) {
1676 1674  
1677 1675 task_lock(current);
... ... @@ -1691,12 +1689,6 @@
1691 1689 ns = current->nsproxy->namespace;
1692 1690 current->nsproxy->namespace = new_ns;
1693 1691 new_ns = ns;
1694   - }
1695   -
1696   - if (new_sigh) {
1697   - sigh = current->sighand;
1698   - rcu_assign_pointer(current->sighand, new_sigh);
1699   - new_sigh = sigh;
1700 1692 }
1701 1693  
1702 1694 if (new_mm) {