From 445c89514be242b1b0080056d50bdc1b72adeb5c Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 2 Dec 2009 19:49:50 +0100 Subject: locking: Convert raw_spinlock to arch_spinlock The raw_spin* namespace was taken by lockdep for the architecture specific implementations. raw_spin_* would be the ideal name space for the spinlocks which are not converted to sleeping locks in preempt-rt. Linus suggested to convert the raw_ to arch_ locks and cleanup the name space instead of using an artifical name like core_spin, atomic_spin or whatever No functional change. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra Acked-by: David S. Miller Acked-by: Ingo Molnar Cc: linux-arch@vger.kernel.org --- arch/x86/kernel/dumpstack.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/kernel/dumpstack.c') diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c index b8ce165dde5d..0862d9d89c92 100644 --- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -188,7 +188,7 @@ void dump_stack(void) } EXPORT_SYMBOL(dump_stack); -static raw_spinlock_t die_lock = __RAW_SPIN_LOCK_UNLOCKED; +static arch_spinlock_t die_lock = __RAW_SPIN_LOCK_UNLOCKED; static int die_owner = -1; static unsigned int die_nest_count; -- cgit v1.2.3 From edc35bd72e2079b25f99c5da7d7a65dbbffc4a26 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 3 Dec 2009 12:38:57 +0100 Subject: locking: Rename __RAW_SPIN_LOCK_UNLOCKED to __ARCH_SPIN_LOCK_UNLOCKED Further name space cleanup. No functional change Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra Acked-by: David S. Miller Acked-by: Ingo Molnar Cc: linux-arch@vger.kernel.org --- arch/x86/kernel/dumpstack.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/kernel/dumpstack.c') diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c index 0862d9d89c92..5b75afac8a38 100644 --- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -188,7 +188,7 @@ void dump_stack(void) } EXPORT_SYMBOL(dump_stack); -static arch_spinlock_t die_lock = __RAW_SPIN_LOCK_UNLOCKED; +static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED; static int die_owner = -1; static unsigned int die_nest_count; -- cgit v1.2.3 From 0199c4e68d1f02894bdefe4b5d9e9ee4aedd8d62 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 2 Dec 2009 20:01:25 +0100 Subject: locking: Convert __raw_spin* functions to arch_spin* Name space cleanup. No functional change. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra Acked-by: David S. Miller Acked-by: Ingo Molnar Cc: linux-arch@vger.kernel.org --- arch/x86/kernel/dumpstack.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'arch/x86/kernel/dumpstack.c') diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c index 5b75afac8a38..0a0aa1cec8f1 100644 --- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -207,11 +207,11 @@ unsigned __kprobes long oops_begin(void) /* racy, but better than risking deadlock. */ raw_local_irq_save(flags); cpu = smp_processor_id(); - if (!__raw_spin_trylock(&die_lock)) { + if (!arch_spin_trylock(&die_lock)) { if (cpu == die_owner) /* nested oops. should stop eventually */; else - __raw_spin_lock(&die_lock); + arch_spin_lock(&die_lock); } die_nest_count++; die_owner = cpu; @@ -231,7 +231,7 @@ void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr) die_nest_count--; if (!die_nest_count) /* Nest count reaches zero, release the lock. */ - __raw_spin_unlock(&die_lock); + arch_spin_unlock(&die_lock); raw_local_irq_restore(flags); oops_exit(); -- cgit v1.2.3 From 61c1917f47f73c968e92d04d15370b1dc3ec4592 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Thu, 17 Dec 2009 05:40:33 +0100 Subject: perf events, x86/stacktrace: Make stack walking optional The current print_context_stack helper that does the stack walking job is good for usual stacktraces as it walks through all the stack and reports even addresses that look unreliable, which is nice when we don't have frame pointers for example. But we have users like perf that only require reliable stacktraces, and those may want a more adapted stack walker, so lets make this function a callback in stacktrace_ops that users can tune for their needs. Signed-off-by: Frederic Weisbecker Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Paul Mackerras LKML-Reference: <1261024834-5336-1-git-send-regression-fweisbec@gmail.com> Signed-off-by: Ingo Molnar --- arch/x86/kernel/dumpstack.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'arch/x86/kernel/dumpstack.c') diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c index 0a0aa1cec8f1..8aaa119b7cad 100644 --- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -141,10 +141,11 @@ static void print_trace_address(void *data, unsigned long addr, int reliable) } static const struct stacktrace_ops print_trace_ops = { - .warning = print_trace_warning, - .warning_symbol = print_trace_warning_symbol, - .stack = print_trace_stack, - .address = print_trace_address, + .warning = print_trace_warning, + .warning_symbol = print_trace_warning_symbol, + .stack = print_trace_stack, + .address = print_trace_address, + .walk_stack = print_context_stack, }; void -- cgit v1.2.3 From 06d65bda75341485d32f33da474b0664819ad497 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Thu, 17 Dec 2009 05:40:34 +0100 Subject: perf events, x86/stacktrace: Fix performance/softlockup by providing a special frame pointer-only stack walker It's just wasteful for stacktrace users like perf to walk through every entries on the stack whereas these only accept reliable ones, ie: that the frame pointer validates. Since perf requires pure reliable stacktraces, it needs a stack walker based on frame pointers-only to optimize the stacktrace processing. This might solve some near-lockup scenarios that can be triggered by call-graph tracing timer events. Signed-off-by: Frederic Weisbecker Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Paul Mackerras LKML-Reference: <1261024834-5336-2-git-send-regression-fweisbec@gmail.com> [ v2: fix for modular builds and small detail tidyup ] Signed-off-by: Ingo Molnar --- arch/x86/kernel/dumpstack.c | 28 ++++++++++++++++++++++++++-- 1 file changed, 26 insertions(+), 2 deletions(-) (limited to 'arch/x86/kernel/dumpstack.c') diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c index 8aaa119b7cad..c56bc2873030 100644 --- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -109,6 +109,30 @@ print_context_stack(struct thread_info *tinfo, } return bp; } +EXPORT_SYMBOL_GPL(print_context_stack); + +unsigned long +print_context_stack_bp(struct thread_info *tinfo, + unsigned long *stack, unsigned long bp, + const struct stacktrace_ops *ops, void *data, + unsigned long *end, int *graph) +{ + struct stack_frame *frame = (struct stack_frame *)bp; + unsigned long *ret_addr = &frame->return_address; + + while (valid_stack_ptr(tinfo, ret_addr, sizeof(*ret_addr), end)) { + unsigned long addr = *ret_addr; + + if (__kernel_text_address(addr)) { + ops->address(data, addr, 1); + frame = frame->next_frame; + ret_addr = &frame->return_address; + print_ftrace_graph_addr(addr, data, ops, tinfo, graph); + } + } + return (unsigned long)frame; +} +EXPORT_SYMBOL_GPL(print_context_stack_bp); static void @@ -143,8 +167,8 @@ static void print_trace_address(void *data, unsigned long addr, int reliable) static const struct stacktrace_ops print_trace_ops = { .warning = print_trace_warning, .warning_symbol = print_trace_warning_symbol, - .stack = print_trace_stack, - .address = print_trace_address, + .stack = print_trace_stack, + .address = print_trace_address, .walk_stack = print_context_stack, }; -- cgit v1.2.3 From c2c5d45d46c8c0fd34291dec958670ad4816796f Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Thu, 31 Dec 2009 03:52:25 +0100 Subject: perf: Stop stack frame walking off kernel addresses boundaries While processing kernel perf callchains, an bad entry can be considered as a valid stack pointer but not as a kernel address. In this case, we hang in an endless loop. This can happen in an x86-32 kernel after processing the last entry in a kernel stacktrace. Just stop the stack frame walking after we encounter an invalid kernel address. This fixes a hard lockup in x86-32. Signed-off-by: Frederic Weisbecker Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Paul Mackerras LKML-Reference: <1262227945-27014-1-git-send-regression-fweisbec@gmail.com> Signed-off-by: Ingo Molnar --- arch/x86/kernel/dumpstack.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) (limited to 'arch/x86/kernel/dumpstack.c') diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c index c56bc2873030..6d817554780a 100644 --- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -123,13 +123,15 @@ print_context_stack_bp(struct thread_info *tinfo, while (valid_stack_ptr(tinfo, ret_addr, sizeof(*ret_addr), end)) { unsigned long addr = *ret_addr; - if (__kernel_text_address(addr)) { - ops->address(data, addr, 1); - frame = frame->next_frame; - ret_addr = &frame->return_address; - print_ftrace_graph_addr(addr, data, ops, tinfo, graph); - } + if (!__kernel_text_address(addr)) + break; + + ops->address(data, addr, 1); + frame = frame->next_frame; + ret_addr = &frame->return_address; + print_ftrace_graph_addr(addr, data, ops, tinfo, graph); } + return (unsigned long)frame; } EXPORT_SYMBOL_GPL(print_context_stack_bp); -- cgit v1.2.3