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Revert "powerpc/hw-breakpoint: Use generic hw-breakpoint interfaces for new PPC ptrace flags"

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This reverts commit 1b788400bb.

It causes oopses when passed incorrect arguments and has a
design fault using IPIs with interrupts disabled.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
This commit is contained in:
Benjamin Herrenschmidt 2012-05-21 10:44:12 +10:00
parent 933b90a988
commit 6749ef0b8b
2 changed files with 6 additions and 87 deletions
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16
Documentation/powerpc/ptrace.txt
View file

@ -127,22 +127,6 @@ Some examples of using the structure to:
p.addr2 = (uint64_t) end_range;
p.condition_value = 0;
- set a watchpoint in server processors (BookS)
p.version = 1;
p.trigger_type = PPC_BREAKPOINT_TRIGGER_RW;
p.addr_mode = PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE;
or
p.addr_mode = PPC_BREAKPOINT_MODE_EXACT;
p.condition_mode = PPC_BREAKPOINT_CONDITION_NONE;
p.addr = (uint64_t) begin_range;
/* For PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE addr2 needs to be specified, where
* addr2 - addr <= 8 Bytes.
*/
p.addr2 = (uint64_t) end_range;
p.condition_value = 0;
3. PTRACE_DELHWDEBUG
Takes an integer which identifies an existing breakpoint or watchpoint

77
arch/powerpc/kernel/ptrace.c
View file

@ -1336,12 +1336,6 @@ static int set_dac_range(struct task_struct *child,
static long ppc_set_hwdebug(struct task_struct *child,
struct ppc_hw_breakpoint *bp_info)
{
#ifdef CONFIG_HAVE_HW_BREAKPOINT
int len = 0;
struct thread_struct *thread = &(child->thread);
struct perf_event *bp;
struct perf_event_attr attr;
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
#ifndef CONFIG_PPC_ADV_DEBUG_REGS
unsigned long dabr;
#endif
@ -1385,9 +1379,13 @@ static long ppc_set_hwdebug(struct task_struct *child,
*/
if ((bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_RW) == 0 ||
(bp_info->trigger_type & ~PPC_BREAKPOINT_TRIGGER_RW) != 0 ||
bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT ||
bp_info->condition_mode != PPC_BREAKPOINT_CONDITION_NONE)
return -EINVAL;
if (child->thread.dabr)
return -ENOSPC;
if ((unsigned long)bp_info->addr >= TASK_SIZE)
return -EIO;
@ -1397,63 +1395,15 @@ static long ppc_set_hwdebug(struct task_struct *child,
dabr |= DABR_DATA_READ;
if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)
dabr |= DABR_DATA_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) {
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;
}
/* Create a new breakpoint request if one doesn't exist already */
hw_breakpoint_init(&attr);
attr.bp_addr = (unsigned long)bp_info->addr & ~HW_BREAKPOINT_ALIGN;
attr.bp_len = len;
arch_bp_generic_fields(dabr & (DABR_DATA_WRITE | DABR_DATA_READ),
&attr.bp_type);
thread->ptrace_bps[0] = bp = register_user_hw_breakpoint(&attr,
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 */
if (bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT)
return -EINVAL;
if (child->thread.dabr)
return -ENOSPC;
child->thread.dabr = dabr;
return 1;
#endif /* !CONFIG_PPC_ADV_DEBUG_DVCS */
}
static long ppc_del_hwdebug(struct task_struct *child, long addr, long data)
{
#ifdef CONFIG_HAVE_HW_BREAKPOINT
int ret = 0;
struct thread_struct *thread = &(child->thread);
struct perf_event *bp;
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
int rc;
@ -1473,25 +1423,10 @@ static long ppc_del_hwdebug(struct task_struct *child, long addr, long data)
#else
if (data != 1)
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.dabr == 0)
return -ENOENT;
child->thread.dabr = 0;
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
return 0;
#endif
@ -1598,7 +1533,7 @@ long arch_ptrace(struct task_struct *child, long request,
dbginfo.data_bp_alignment = 4;
#endif
dbginfo.sizeof_condition = 0;
dbginfo.features = PPC_DEBUG_FEATURE_DATA_BP_RANGE;
dbginfo.features = 0;
#endif /* CONFIG_PPC_ADV_DEBUG_REGS */
if (!access_ok(VERIFY_WRITE, datavp,