OpenCloudOS-Kernel/arch
Jiri Olsa ceea991a01 bpf: Move bpf_dispatcher function out of ftrace locations
The dispatcher function is attached/detached to trampoline by
dispatcher update function. At the same time it's available as
ftrace attachable function.

After discussion [1] the proposed solution is to use compiler
attributes to alter bpf_dispatcher_##name##_func function:

  - remove it from being instrumented with __no_instrument_function__
    attribute, so ftrace has no track of it

  - but still generate 5 nop instructions with patchable_function_entry(5)
    attribute, which are expected by bpf_arch_text_poke used by
    dispatcher update function

Enabling HAVE_DYNAMIC_FTRACE_NO_PATCHABLE option for x86, so
__patchable_function_entries functions are not part of ftrace/mcount
locations.

Adding attributes to bpf_dispatcher_XXX function on x86_64 so it's
kept out of ftrace locations and has 5 byte nop generated at entry.

These attributes need to be arch specific as pointed out by Ilya
Leoshkevic in here [2].

The dispatcher image is generated only for x86_64 arch, so the
code can stay as is for other archs.

  [1] https://lore.kernel.org/bpf/20220722110811.124515-1-jolsa@kernel.org/
  [2] https://lore.kernel.org/bpf/969a14281a7791c334d476825863ee449964dd0c.camel@linux.ibm.com/

Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/bpf/20220903131154.420467-3-jolsa@kernel.org
2022-09-16 22:23:20 +02:00
..
alpha provide arch_test_bit_acquire for architectures that define test_bit 2022-08-27 09:49:54 -07:00
arc Kbuild updates for v5.20 2022-08-10 10:40:41 -07:00
arm Merge 'irq/loongarch', 'pci/ctrl/loongson' and 'pci/header-cleanup-immutable' 2022-08-11 21:06:14 +08:00
arm64 bpf: arm64: No support of struct argument in trampoline programs 2022-09-06 19:51:14 -07:00
csky Merge 'irq/loongarch', 'pci/ctrl/loongson' and 'pci/header-cleanup-immutable' 2022-08-11 21:06:14 +08:00
hexagon provide arch_test_bit_acquire for architectures that define test_bit 2022-08-27 09:49:54 -07:00
ia64 provide arch_test_bit_acquire for architectures that define test_bit 2022-08-27 09:49:54 -07:00
loongarch LoongArch: mm: Avoid unnecessary page fault retires on shared memory types 2022-08-25 19:34:59 +08:00
m68k provide arch_test_bit_acquire for architectures that define test_bit 2022-08-27 09:49:54 -07:00
microblaze - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe 2022-08-05 16:32:45 -07:00
mips Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2022-09-06 23:21:18 +02:00
nios2 nios2: add force_successful_syscall_return() 2022-08-15 11:25:32 -05:00
openrisc Updates to various subsystems which I help look after. lib, ocfs2, 2022-08-07 10:03:24 -07:00
parisc parisc: Add runtime check to prevent PA2.0 kernels on PA1.x machines 2022-08-22 11:09:17 +02:00
powerpc Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-08-25 16:07:42 -07:00
riscv RISC-V Fixes for 6.0-rc3 2022-08-26 11:26:27 -07:00
s390 s390 updates for 6.0-rc3 2022-08-27 15:40:51 -07:00
sh provide arch_test_bit_acquire for architectures that define test_bit 2022-08-27 09:49:54 -07:00
sparc Merge 'irq/loongarch', 'pci/ctrl/loongson' and 'pci/header-cleanup-immutable' 2022-08-11 21:06:14 +08:00
um asm goto: eradicate CC_HAS_ASM_GOTO 2022-08-21 10:06:28 -07:00
x86 bpf: Move bpf_dispatcher function out of ftrace locations 2022-09-16 22:23:20 +02:00
xtensa Merge 'irq/loongarch', 'pci/ctrl/loongson' and 'pci/header-cleanup-immutable' 2022-08-11 21:06:14 +08:00
.gitignore
Kconfig asm goto: eradicate CC_HAS_ASM_GOTO 2022-08-21 10:06:28 -07:00