Steven Rostedt (Red Hat)
102c9323c3
tracing: Add __tracepoint_string() to export string pointers
...
There are several tracepoints (mostly in RCU), that reference a string
pointer and uses the print format of "%s" to display the string that
exists in the kernel, instead of copying the actual string to the
ring buffer (saves time and ring buffer space).
But this has an issue with userspace tools that read the binary buffers
that has the address of the string but has no access to what the string
itself is. The end result is just output that looks like:
rcu_dyntick: ffffffff818adeaa 1 0
rcu_dyntick: ffffffff818adeb5 0 140000000000000
rcu_dyntick: ffffffff818adeb5 0 140000000000000
rcu_utilization: ffffffff8184333b
rcu_utilization: ffffffff8184333b
The above is pretty useless when read by the userspace tools. Ideally
we would want something that looks like this:
rcu_dyntick: Start 1 0
rcu_dyntick: End 0 140000000000000
rcu_dyntick: Start 140000000000000 0
rcu_callback: rcu_preempt rhp=0xffff880037aff710 func=put_cred_rcu 0/4
rcu_callback: rcu_preempt rhp=0xffff880078961980 func=file_free_rcu 0/5
rcu_dyntick: End 0 1
The trace_printk() which also only stores the address of the string
format instead of recording the string into the buffer itself, exports
the mapping of kernel addresses to format strings via the printk_format
file in the debugfs tracing directory.
The tracepoint strings can use this same method and output the format
to the same file and the userspace tools will be able to decipher
the address without any modification.
The tracepoint strings need its own section to save the strings because
the trace_printk section will cause the trace_printk() buffers to be
allocated if anything exists within the section. trace_printk() is only
used for debugging and should never exist in the kernel, we can not use
the trace_printk sections.
Add a new tracepoint_str section that will also be examined by the output
of the printk_format file.
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-07-26 13:39:44 -04:00
..
bitops
Merge branch 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
2012-10-14 13:39:34 -07:00
4level-fixup.h
atomic-long.h
atomic.h
asm-generic: move cmpxchg*_local defs to cmpxchg.h
2013-03-13 06:11:05 +01:00
atomic64.h
audit_change_attr.h
audit: support the "standard" <asm-generic/unistd.h>
2011-05-04 14:41:28 -04:00
audit_dir_write.h
audit: support the "standard" <asm-generic/unistd.h>
2011-05-04 14:41:28 -04:00
audit_read.h
audit: support the "standard" <asm-generic/unistd.h>
2011-05-04 14:41:28 -04:00
audit_signal.h
audit_write.h
audit: support the "standard" <asm-generic/unistd.h>
2011-05-04 14:41:28 -04:00
barrier.h
Create asm-generic/barrier.h
2012-03-28 18:30:03 +01:00
bitops.h
bitops: remove minix bitops from asm/bitops.h
2011-03-23 19:46:22 -07:00
bitsperlong.h
UAPI: (Scripted) Disintegrate include/asm-generic
2012-10-04 18:20:15 +01:00
bug.h
bug.h: Fix up CONFIG_BUG=n implicit function declarations.
2012-06-25 10:32:49 -07:00
bugs.h
cache.h
cacheflush.h
asm-generic/cacheflush.h: flush icache when copying to user pages
2011-05-25 08:39:37 -07:00
checksum.h
asm-generic headers: Allow yet more arch overrides in checksum.h
2013-02-11 20:00:33 +05:30
clkdev.h
asm-generic: Add default clkdev.h
2012-10-03 21:33:53 +02:00
cmpxchg-local.h
generic: Use raw local irq variant for generic cmpxchg
2013-02-19 08:43:37 +01:00
cmpxchg.h
asm-generic: move cmpxchg*_local defs to cmpxchg.h
2013-03-13 06:11:05 +01:00
cputime.h
cputime: Generic on-demand virtual cputime accounting
2013-01-27 19:23:27 +01:00
cputime_jiffies.h
cputime: Move default nsecs_to_cputime() to jiffies based cputime file
2013-01-27 19:23:25 +01:00
cputime_nsecs.h
cputime_nsecs: use math64.h for nsec resolution conversion helpers
2013-04-26 18:58:12 +02:00
current.h
delay.h
asm-generic: delay.h fix udelay and ndelay for 8 bit args
2011-07-22 18:45:33 +02:00
device.h
div64.h
dma-coherent.h
common: dma-mapping: add support for generic dma_mmap_* calls
2012-07-30 12:25:46 +02:00
dma-contiguous.h
mm: cma: fix condition check when setting global cma area
2012-07-06 12:02:04 +02:00
dma-mapping-broken.h
asm-generic/dma-mapping-broken.h: Provide dma_alloc_attrs()/dma_free_attrs()
2012-12-25 20:14:54 +01:00
dma-mapping-common.h
common: dma-mapping: introduce dma_get_sgtable() function
2012-07-30 12:25:46 +02:00
dma.h
emergency-restart.h
exec.h
Split arch_align_stack() out from asm-generic/system.h
2012-03-28 18:30:03 +01:00
fb.h
ftrace.h
asm-generic headers: add ftrace.h
2011-03-17 09:19:04 +08:00
futex.h
futex: Sanitize futex ops argument types
2011-03-11 12:23:31 +01:00
getorder.h
bitops: Add missing parentheses to new get_order macro
2012-02-24 10:39:27 -08:00
gpio.h
gpiolib: let gpio_chip reference its descriptors
2013-02-11 22:21:28 +00:00
hardirq.h
hugetlb.h
mm/hugetlb: add more arch-defined huge_pte functions
2013-04-29 15:54:33 -07:00
hw_irq.h
ide_iops.h
int-l64.h
UAPI: (Scripted) Disintegrate include/asm-generic
2012-10-04 18:20:15 +01:00
int-ll64.h
UAPI: (Scripted) Disintegrate include/asm-generic
2012-10-04 18:20:15 +01:00
io-64-nonatomic-hi-lo.h
asm-generic: architecture independent readq/writeq for 32bit environment
2012-02-21 16:47:28 -08:00
io-64-nonatomic-lo-hi.h
asm-generic: architecture independent readq/writeq for 32bit environment
2012-02-21 16:47:28 -08:00
io.h
kernel: Fix s390 absolute memory access for /dev/mem
2013-05-22 09:45:57 +02:00
ioctl.h
UAPI: (Scripted) Disintegrate include/asm-generic
2012-10-04 18:20:15 +01:00
iomap.h
[PARISC] fix compile break caused by iomap: make IOPORT/PCI mapping functions conditional
2012-02-27 09:43:30 -06:00
irq.h
irq_regs.h
irqflags.h
Kbuild.asm
UAPI: Set up uapi/asm/Kbuild.asm
2012-10-02 18:01:56 +01:00
kdebug.h
kmap_types.h
asm-generic: remove km_type definitions
2012-07-24 15:27:30 +08:00
kvm_para.h
KVM: add kvm_para_available to asm-generic/kvm_para.h
2013-06-05 13:21:29 +03:00
libata-portmap.h
linkage.h
local.h
atomic: use <linux/atomic.h>
2011-07-26 16:49:47 -07:00
local64.h
atomic: use <linux/atomic.h>
2011-07-26 16:49:47 -07:00
memory_model.h
mm: fix __page_to_pfn for a const struct page argument
2011-08-17 13:00:20 -07:00
mm_hooks.h
mmu.h
asm-generic/mmu.h: Add support for FDPIC
2012-12-09 23:14:14 +01:00
mmu_context.h
module.h
Make most arch asm/module.h files use asm-generic/module.h
2012-09-28 14:31:03 +09:30
mutex-dec.h
arch: Make __mutex_fastpath_lock_retval return whether fastpath succeeded or not
2013-06-26 12:10:55 +02:00
mutex-null.h
arch: Make __mutex_fastpath_lock_retval return whether fastpath succeeded or not
2013-06-26 12:10:55 +02:00
mutex-xchg.h
arch: Make __mutex_fastpath_lock_retval return whether fastpath succeeded or not
2013-06-26 12:10:55 +02:00
mutex.h
page.h
The following changes since commit 3ee72ca992
2012-01-10 17:39:40 -08:00
param.h
UAPI: (Scripted) Disintegrate include/asm-generic
2012-10-04 18:20:15 +01:00
parport.h
include: remove __dev* attributes.
2013-01-03 15:57:16 -08:00
pci-bridge.h
PCI: work around Stratus ftServer broken PCIe hierarchy
2012-04-30 15:21:02 -06:00
pci-dma-compat.h
pci.h
PCI: collapse pcibios_resource_to_bus
2012-02-23 20:19:04 -07:00
pci_iomap.h
[PARISC] fix compile break caused by iomap: make IOPORT/PCI mapping functions conditional
2012-02-27 09:43:30 -06:00
percpu.h
pgalloc.h
pgtable-nopmd.h
pgtable-nopud.h
pgtable.h
Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
2013-07-04 10:29:23 -07:00
ptrace.h
asm-generic/ptrace.h: start a common low level ptrace helper
2011-05-26 17:12:36 -07:00
resource.h
UAPI: (Scripted) Disintegrate include/asm-generic
2012-10-04 18:20:15 +01:00
rtc.h
rwsem.h
Hexagon: Add locking types and functions
2011-11-01 07:34:20 -07:00
scatterlist.h
sections.h
vmlinux.lds: add comments for global variables and clean up useless declarations
2013-07-03 16:07:34 -07:00
segment.h
serial.h
siginfo.h
UAPI: (Scripted) Disintegrate include/asm-generic
2012-10-04 18:20:15 +01:00
signal.h
unify default ptrace_signal_deliver
2012-11-29 00:01:23 -05:00
sizes.h
ARM: 7430/1: sizes.h: move from asm-generic to <linux/sizes.h>
2012-06-28 17:14:34 +01:00
spinlock.h
statfs.h
UAPI: (Scripted) Disintegrate include/asm-generic
2012-10-04 18:20:15 +01:00
string.h
switch_to.h
Split the switch_to() wrapper out of asm-generic/system.h
2012-03-28 18:30:03 +01:00
syscall.h
asm/syscall.h: add syscall_get_arch
2012-04-14 11:13:19 +10:00
syscalls.h
burying unused conditionals
2013-02-14 09:21:15 -05:00
termios-base.h
termios.h
UAPI: (Scripted) Disintegrate include/asm-generic
2012-10-04 18:20:15 +01:00
timex.h
tlb.h
arch, mm: Remove tlb_fast_mode()
2013-06-06 10:07:26 +09:00
tlbflush.h
BUG: headers with BUG/BUG_ON etc. need linux/bug.h
2012-03-04 17:54:34 -05:00
topology.h
trace_clock.h
tracing,x86: Add a TSC trace_clock
2012-11-13 15:48:27 -05:00
uaccess-unaligned.h
uaccess.h
asm-generic: uaccess s/might_sleep/might_fault/
2013-05-28 09:41:05 +02:00
unaligned.h
unistd.h
We get rid of the general module prefix confusion with a binary config option,
2013-05-05 10:58:06 -07:00
user.h
asm-generic/user.h: Fix spelling in comment
2011-03-01 15:49:39 +01:00
vga.h
vmlinux.lds.h
tracing: Add __tracepoint_string() to export string pointers
2013-07-26 13:39:44 -04:00
word-at-a-time.h
word-at-a-time: make the interfaces truly generic
2012-05-26 11:33:40 -07:00
xor.h
asm-generic: xor: mark static functions as __maybe_unused
2012-10-03 21:21:06 +02:00