Subject: [merged] ptrace-powerpc-revert-hw_breakpoints-fix-racy-access-to-ptrace-breakpoints.patch removed from -mm tree
To: oleg@xxxxxxxxxx,benh@xxxxxxxxxxxxxxxxxxx,fweisbec@xxxxxxxxx,jan.kratochvil@xxxxxxxxxx,lethal@xxxxxxxxxxxx,linux@xxxxxxxxxxxxxxxx,mikey@xxxxxxxxxxx,mingo@xxxxxxxxxx,paulus@xxxxxxxxx,prasad@xxxxxxxxxxxxxxxxxx,will.deacon@xxxxxxx,mm-commits@xxxxxxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Tue, 09 Jul 2013 16:21:05 -0700
The patch titled
Subject: ptrace/powerpc: revert "hw_breakpoints: Fix racy access to ptrace breakpoints"
has been removed from the -mm tree. Its filename was
ptrace-powerpc-revert-hw_breakpoints-fix-racy-access-to-ptrace-breakpoints.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Oleg Nesterov <oleg@xxxxxxxxxx>
Subject: ptrace/powerpc: revert "hw_breakpoints: Fix racy access to ptrace breakpoints"
This reverts commit 07fa7a0a8a586 ("hw_breakpoints: Fix racy access to
ptrace breakpoints") and removes ptrace_get/put_breakpoints() added by
other commits.
The patch was fine but we can no longer race with SIGKILL after 9899d11f
("ptrace: ensure arch_ptrace/ptrace_request can never race with SIGKILL"),
the __TASK_TRACED tracee can't be woken up and ->ptrace_bps[] can't go
away.
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Acked-by: Michael Neuling <mikey@xxxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jan Kratochvil <jan.kratochvil@xxxxxxxxxx>
Cc: Paul Mundt <lethal@xxxxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: Prasad <prasad@xxxxxxxxxxxxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/kernel/ptrace.c | 30 ++++--------------------------
1 file changed, 4 insertions(+), 26 deletions(-)
diff -puN arch/powerpc/kernel/ptrace.c~ptrace-powerpc-revert-hw_breakpoints-fix-racy-access-to-ptrace-breakpoints arch/powerpc/kernel/ptrace.c
--- a/arch/powerpc/kernel/ptrace.c~ptrace-powerpc-revert-hw_breakpoints-fix-racy-access-to-ptrace-breakpoints
+++ a/arch/powerpc/kernel/ptrace.c
@@ -975,16 +975,12 @@ int ptrace_set_debugreg(struct task_stru
hw_brk.type = (data & HW_BRK_TYPE_DABR) | HW_BRK_TYPE_PRIV_ALL;
hw_brk.len = 8;
#ifdef CONFIG_HAVE_HW_BREAKPOINT
- if (ptrace_get_breakpoints(task) < 0)
- return -ESRCH;
-
bp = thread->ptrace_bps[0];
if ((!data) || !(hw_brk.type & HW_BRK_TYPE_RDWR)) {
if (bp) {
unregister_hw_breakpoint(bp);
thread->ptrace_bps[0] = NULL;
}
- ptrace_put_breakpoints(task);
return 0;
}
if (bp) {
@@ -997,11 +993,9 @@ int ptrace_set_debugreg(struct task_stru
ret = modify_user_hw_breakpoint(bp, &attr);
if (ret) {
- ptrace_put_breakpoints(task);
return ret;
}
thread->ptrace_bps[0] = bp;
- ptrace_put_breakpoints(task);
thread->hw_brk = hw_brk;
return 0;
}
@@ -1016,12 +1010,9 @@ int ptrace_set_debugreg(struct task_stru
ptrace_triggered, NULL, task);
if (IS_ERR(bp)) {
thread->ptrace_bps[0] = NULL;
- ptrace_put_breakpoints(task);
return PTR_ERR(bp);
}
- ptrace_put_breakpoints(task);
-
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
task->thread.hw_brk = hw_brk;
#else /* CONFIG_PPC_ADV_DEBUG_REGS */
@@ -1440,26 +1431,19 @@ static long ppc_set_hwdebug(struct task_
if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)
brk.type |= HW_BRK_TYPE_WRITE;
#ifdef CONFIG_HAVE_HW_BREAKPOINT
- if (ptrace_get_breakpoints(child) < 0)
- return -ESRCH;
-
/*
* Check if the request is for 'range' breakpoints. We can
* support it if range < 8 bytes.
*/
- if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE) {
+ if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE)
len = bp_info->addr2 - bp_info->addr;
- } else if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_EXACT)
+ else if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_EXACT)
len = 1;
- else {
- ptrace_put_breakpoints(child);
+ else
return -EINVAL;
- }
bp = thread->ptrace_bps[0];
- if (bp) {
- ptrace_put_breakpoints(child);
+ if (bp)
return -ENOSPC;
- }
/* Create a new breakpoint request if one doesn't exist already */
hw_breakpoint_init(&attr);
@@ -1471,11 +1455,9 @@ static long ppc_set_hwdebug(struct task_
ptrace_triggered, NULL, child);
if (IS_ERR(bp)) {
thread->ptrace_bps[0] = NULL;
- ptrace_put_breakpoints(child);
return PTR_ERR(bp);
}
- ptrace_put_breakpoints(child);
return 1;
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
@@ -1519,16 +1501,12 @@ static long ppc_del_hwdebug(struct task_
return -EINVAL;
#ifdef CONFIG_HAVE_HW_BREAKPOINT
- if (ptrace_get_breakpoints(child) < 0)
- return -ESRCH;
-
bp = thread->ptrace_bps[0];
if (bp) {
unregister_hw_breakpoint(bp);
thread->ptrace_bps[0] = NULL;
} else
ret = -ENOENT;
- ptrace_put_breakpoints(child);
return ret;
#else /* CONFIG_HAVE_HW_BREAKPOINT */
if (child->thread.hw_brk.address == 0)
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
origin.patch
linux-next.patch
mm-mempolicy-fix-mbind_range-vma_adjust-interaction.patch
include-linux-schedh-dont-use-task-pid-tgid-in-same_thread_group-has_group_leader_pid.patch
lockdep-introduce-lock_acquire_exclusive-shared-helper-macros.patch
lglock-update-lockdep-annotations-to-report-recursive-local-locks.patch
fput-task_work_add-can-fail-if-the-caller-has-passed-exit_task_work-fix.patch
fput-turn-list_head-delayed_fput_list-into-llist_head.patch
llist-fix-simplify-llist_add-and-llist_add_batch.patch
llist-llist_add-can-use-llist_add_batch.patch
kernel-wide-fix-missing-validations-on-__get-__put-__copy_to-__copy_from_user.patch
autofs4-allow-autofs-to-work-outside-the-initial-pid-namespace.patch
autofs4-translate-pids-to-the-right-namespace-for-the-daemon.patch
signals-eventpoll-set-saved_sigmask-at-the-start.patch
move-exit_task_namespaces-outside-of-exit_notify-fix.patch
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