diff options
author | Oleg Nesterov <oleg@redhat.com> | 2013-05-23 10:38:02 +1000 |
---|---|---|
committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2013-05-29 14:50:13 +1000 |
commit | eddce4350c64ecc221e43a1397bd574a02c218f2 (patch) | |
tree | 9573bf40edf43639dd1085bf3e2e20489c8d6dd3 /arch | |
parent | 215ae011d8d09fdf025a424314ec699ce5526601 (diff) |
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@redhat.com>
Acked-by: Michael Neuling <mikey@neuling.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Prasad <prasad@linux.vnet.ibm.com>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/powerpc/kernel/ptrace.c | 20 |
1 files changed, 0 insertions, 20 deletions
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c index 98c2fc198712..6645e573c44c 100644 --- a/arch/powerpc/kernel/ptrace.c +++ b/arch/powerpc/kernel/ptrace.c @@ -975,16 +975,12 @@ int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, 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_struct *task, unsigned long addr, 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_struct *task, unsigned long addr, 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 */ @@ -1440,9 +1431,6 @@ static long ppc_set_hwdebug(struct task_struct *child, 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. @@ -1450,12 +1438,10 @@ static long ppc_set_hwdebug(struct task_struct *child, 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) { - ptrace_put_breakpoints(child); return -EINVAL; } bp = thread->ptrace_bps[0]; if (bp) { - ptrace_put_breakpoints(child); return -ENOSPC; } @@ -1469,11 +1455,9 @@ static long ppc_set_hwdebug(struct task_struct *child, 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 */ @@ -1517,16 +1501,12 @@ static long ppc_del_hwdebug(struct task_struct *child, long data) 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) |