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Don't check the same stack liveness condition 8 times.
once is enough.
Signed-off-by: Alexei Starovoitov <[email protected]>
Acked-by: Edward Cree <[email protected]>
Acked-by: Jakub Kicinski <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
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This patch adds bpf_line_info during the verifier's verbose.
It can give error context for debug purpose.
~~~~~~~~~~
Here is the verbose log for backedge:
while (a) {
a += bpf_get_smp_processor_id();
bpf_trace_printk(fmt, sizeof(fmt), a);
}
~> bpftool prog load ./test_loop.o /sys/fs/bpf/test_loop type tracepoint
13: while (a) {
3: a += bpf_get_smp_processor_id();
back-edge from insn 13 to 3
~~~~~~~~~~
Here is the verbose log for invalid pkt access:
Modification to test_xdp_noinline.c:
data = (void *)(long)xdp->data;
data_end = (void *)(long)xdp->data_end;
/*
if (data + 4 > data_end)
return XDP_DROP;
*/
*(u32 *)data = dst->dst;
~> bpftool prog load ./test_xdp_noinline.o /sys/fs/bpf/test_xdp_noinline type xdp
; data = (void *)(long)xdp->data;
224: (79) r2 = *(u64 *)(r10 -112)
225: (61) r2 = *(u32 *)(r2 +0)
; *(u32 *)data = dst->dst;
226: (63) *(u32 *)(r2 +0) = r1
invalid access to packet, off=0 size=4, R2(id=0,off=0,r=0)
R2 offset is outside of the packet
Signed-off-by: Martin KaFai Lau <[email protected]>
Acked-by: Yonghong Song <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
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The current btf_name_by_offset() is returning "(anon)" type name for
the offset == 0 case and "(invalid-name-offset)" for the out-of-bound
offset case.
It fits well for the internal BTF verbose log purpose which
is focusing on type. For example,
offset == 0 => "(anon)" => anonymous type/name.
Returning non-NULL for the bad offset case is needed
during the BTF verification process because the BTF verifier may
complain about another field first before discovering the name_off
is invalid.
However, it may not be ideal for the newer use case which does not
necessary mean type name. For example, when logging line_info
in the BPF verifier in the next patch, it is better to log an
empty src line instead of logging "(anon)".
The existing bpf_name_by_offset() is renamed to __bpf_name_by_offset()
and static to btf.c.
A new bpf_name_by_offset() is added for generic context usage. It
returns "\0" for name_off == 0 (note that btf->strings[0] is "\0")
and NULL for invalid offset. It allows the caller to decide
what is the best output in its context.
The new btf_name_by_offset() is overlapped with btf_name_offset_valid().
Hence, btf_name_offset_valid() is removed from btf.h to keep the btf.h API
minimal. The existing btf_name_offset_valid() usage in btf.c could also be
replaced later.
Signed-off-by: Martin KaFai Lau <[email protected]>
Acked-by: Yonghong Song <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
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Thumb-2 functions have the lowest bit set in the symbol value in the
symtab. When kallsyms are generated for the vmlinux, the kallsyms are
generated from the output of nm, and nm clears the lowest bit.
$ arm-linux-gnueabihf-readelf -a vmlinux | grep show_interrupts
95947: 8015dc89 686 FUNC GLOBAL DEFAULT 2 show_interrupts
$ arm-linux-gnueabihf-nm vmlinux | grep show_interrupts
8015dc88 T show_interrupts
$ cat /proc/kallsyms | grep show_interrupts
8015dc88 T show_interrupts
However, for modules, the kallsyms uses the values in the symbol table
without modification, so for functions in modules, the lowest bit is set
in kallsyms.
$ arm-linux-gnueabihf-readelf -a drivers/net/tun.ko | grep tun_get_socket
333: 00002d4d 36 FUNC GLOBAL DEFAULT 1 tun_get_socket
$ arm-linux-gnueabihf-nm drivers/net/tun.ko | grep tun_get_socket
00002d4c T tun_get_socket
$ cat /proc/kallsyms | grep tun_get_socket
7f802d4d t tun_get_socket [tun]
Because of this, the symbol+offset of the crashing instruction shown in
oopses is incorrect when the crash is in a module. For example, given a
tun_get_socket which starts like this,
00002d4c <tun_get_socket>:
2d4c: 6943 ldr r3, [r0, #20]
2d4e: 4a07 ldr r2, [pc, #28]
2d50: 4293 cmp r3, r2
a crash when tun_get_socket is called with NULL results in:
PC is at tun_xdp+0xa3/0xa4 [tun]
pc : [<7f802d4c>]
As can be seen, the "PC is at" line reports the wrong symbol name, and
the symbol+offset will point to the wrong source line if it is passed to
gdb.
To solve this, add a way for archs to fixup the reading of these module
kallsyms values, and use that to clear the lowest bit for function
symbols on Thumb-2.
After the fix:
# cat /proc/kallsyms | grep tun_get_socket
7f802d4c t tun_get_socket [tun]
PC is at tun_get_socket+0x0/0x24 [tun]
pc : [<7f802d4c>]
Signed-off-by: Vincent Whitchurch <[email protected]>
Signed-off-by: Jessica Yu <[email protected]>
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st_info is currently overwritten after relocation and used to store the
elf_type(). However, we're going to need it fix kallsyms on ARM's
Thumb-2 kernels, so preserve st_info and overwrite the st_size field
instead. st_size is neither used by the module core nor by any
architecture.
Reviewed-by: Miroslav Benes <[email protected]>
Reviewed-by: Dave Martin <[email protected]>
Signed-off-by: Vincent Whitchurch <[email protected]>
Signed-off-by: Jessica Yu <[email protected]>
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Remove duplicated include.
Signed-off-by: YueHaibing <[email protected]>
Signed-off-by: Paul Moore <[email protected]>
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sparse complains,
kernel/seccomp.c:1172:13: warning: incorrect type in assignment (different base types)
kernel/seccomp.c:1172:13: expected restricted __poll_t [usertype] ret
kernel/seccomp.c:1172:13: got int
kernel/seccomp.c:1173:13: warning: restricted __poll_t degrades to integer
Instead of assigning this to ret, since we don't use this anywhere, let's
just test it against 0 directly.
Signed-off-by: Tycho Andersen <[email protected]>
Reported-by: 0day robot <[email protected]>
Fixes: 6a21cc50f0c7 ("seccomp: add a return code to trap to userspace")
Signed-off-by: Kees Cook <[email protected]>
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This logic is not needed anymore since we got rid of the verifier
rewrite that was using prog->aux address in f6069b9aa993 ("bpf:
fix redirect to map under tail calls").
Signed-off-by: Daniel Borkmann <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
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Avoid expensive indirect calls in the fast path DMA mapping
operations by directly calling the dma_direct_* ops if we are using
the directly mapped DMA operations.
Signed-off-by: Christoph Hellwig <[email protected]>
Acked-by: Jesper Dangaard Brouer <[email protected]>
Tested-by: Jesper Dangaard Brouer <[email protected]>
Tested-by: Tony Luck <[email protected]>
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While the dma-direct code is (relatively) clean and simple we actually
have to use the swiotlb ops for the mapping on many architectures due
to devices with addressing limits. Instead of keeping two
implementations around this commit allows the dma-direct
implementation to call the swiotlb bounce buffering functions and
thus share the guts of the mapping implementation. This also
simplified the dma-mapping setup on a few architectures where we
don't have to differenciate which implementation to use.
Signed-off-by: Christoph Hellwig <[email protected]>
Acked-by: Jesper Dangaard Brouer <[email protected]>
Tested-by: Jesper Dangaard Brouer <[email protected]>
Tested-by: Tony Luck <[email protected]>
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No need to duplicate the mapping logic.
Signed-off-by: Christoph Hellwig <[email protected]>
Acked-by: Jesper Dangaard Brouer <[email protected]>
Tested-by: Jesper Dangaard Brouer <[email protected]>
Tested-by: Tony Luck <[email protected]>
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Only report report a DMA addressability report once to avoid spewing the
kernel log with repeated message. Also provide a stack trace to make it
easy to find the actual caller that caused the problem.
Last but not least move the actual check into the fast path and only
leave the error reporting in a helper.
Signed-off-by: Christoph Hellwig <[email protected]>
Acked-by: Jesper Dangaard Brouer <[email protected]>
Tested-by: Jesper Dangaard Brouer <[email protected]>
Tested-by: Tony Luck <[email protected]>
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Instead of providing a special dma_mark_clean hook just for ia64, switch
ia64 to use the normal arch_sync_dma_for_cpu hooks instead.
This means that we now also set the PG_arch_1 bit for pages in the
swiotlb buffer, which isn't stricly needed as we will never execute code
out of the swiotlb buffer, but otherwise harmless.
Signed-off-by: Christoph Hellwig <[email protected]>
Acked-by: Jesper Dangaard Brouer <[email protected]>
Tested-by: Jesper Dangaard Brouer <[email protected]>
Tested-by: Tony Luck <[email protected]>
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We can use DMA_MAPPING_ERROR instead, which already maps to the same
value.
Signed-off-by: Christoph Hellwig <[email protected]>
Acked-by: Jesper Dangaard Brouer <[email protected]>
Tested-by: Jesper Dangaard Brouer <[email protected]>
Tested-by: Tony Luck <[email protected]>
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The dummy DMA ops are currently used by arm64 for any device which has
an invalid ACPI description and is thus barred from using DMA due to not
knowing whether is is cache-coherent or not. Factor these out into
general dma-mapping code so that they can be referenced from other
common code paths. In the process, we can prune all the optional
callbacks which just do the same thing as the default behaviour, and
fill in .map_resource for completeness.
Signed-off-by: Robin Murphy <[email protected]>
[hch: moved to a separate source file]
Reviewed-by: Rafael J. Wysocki <[email protected]>
Acked-by: Jesper Dangaard Brouer <[email protected]>
Tested-by: Jesper Dangaard Brouer <[email protected]>
Tested-by: Tony Luck <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
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All architectures except for sparc64 use the dma-direct code in some
form, and even for sparc64 we had the discussion of a direct mapping
mode a while ago. In preparation for directly calling the direct
mapping code don't bother having it optionally but always build the
code in. This is a minor hardship for some powerpc and arm configs
that don't pull it in yet (although they should in a relase ot two),
and sparc64 which currently doesn't need it at all, but it will
reduce the ifdef mess we'd otherwise need significantly.
Signed-off-by: Christoph Hellwig <[email protected]>
Acked-by: Jesper Dangaard Brouer <[email protected]>
Tested-by: Jesper Dangaard Brouer <[email protected]>
Tested-by: Tony Luck <[email protected]>
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This isn't exactly a slow path routine, but it is not super critical
either, and moving it out of line will help to keep the include chain
clean for the following DMA indirection bypass work.
Signed-off-by: Christoph Hellwig <[email protected]>
Acked-by: Jesper Dangaard Brouer <[email protected]>
Tested-by: Jesper Dangaard Brouer <[email protected]>
Tested-by: Tony Luck <[email protected]>
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There is no need to have all setup and coherent allocation / freeing
routines inline. Move them out of line to keep the implemeation
nicely encapsulated and save some kernel text size.
Signed-off-by: Christoph Hellwig <[email protected]>
Acked-by: Jesper Dangaard Brouer <[email protected]>
Tested-by: Jesper Dangaard Brouer <[email protected]>
Tested-by: Tony Luck <[email protected]>
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dma_get_required_mask should really be with the rest of the DMA mapping
implementation instead of in drivers/base as a lone outlier.
Signed-off-by: Christoph Hellwig <[email protected]>
Acked-by: Jesper Dangaard Brouer <[email protected]>
Tested-by: Jesper Dangaard Brouer <[email protected]>
Tested-by: Tony Luck <[email protected]>
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We can just call the regular calls after adding offset the the address instead
of reimplementing them.
Signed-off-by: Christoph Hellwig <[email protected]>
Acked-by: Jesper Dangaard Brouer <[email protected]>
Tested-by: Jesper Dangaard Brouer <[email protected]>
Tested-by: Tony Luck <[email protected]>
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We already zero the memory after allocating it from the pool that
this function fills, and having the memset here in this form means
we can't support CMA highmem allocations.
Signed-off-by: Christoph Hellwig <[email protected]>
Reported-by: Russell King - ARM Linux <[email protected]>
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Currently for liveness and state pruning the register parentage
chains don't include states of the callee. This makes some sense
as the callee can't access those registers. However, this means
that READs done after the callee returns will not propagate into
the states of the callee. Callee will then perform pruning
disregarding differences in caller state.
Example:
0: (85) call bpf_user_rnd_u32
1: (b7) r8 = 0
2: (55) if r0 != 0x0 goto pc+1
3: (b7) r8 = 1
4: (bf) r1 = r8
5: (85) call pc+4
6: (15) if r8 == 0x1 goto pc+1
7: (05) *(u64 *)(r9 - 8) = r3
8: (b7) r0 = 0
9: (95) exit
10: (15) if r1 == 0x0 goto pc+0
11: (95) exit
Here we acquire unknown state with call to get_random() [1]. Then
we store this random state in r8 (either 0 or 1) [1 - 3], and make
a call on line 5. Callee does nothing but a trivial conditional
jump (to create a pruning point). Upon return caller checks the
state of r8 and either performs an unsafe read or not.
Verifier will first explore the path with r8 == 1, creating a pruning
point at [11]. The parentage chain for r8 will include only callers
states so once verifier reaches [6] it will mark liveness only on states
in the caller, and not [11]. Now when verifier walks the paths with
r8 == 0 it will reach [11] and since REG_LIVE_READ on r8 was not
propagated there it will prune the walk entirely (stop walking
the entire program, not just the callee). Since [6] was never walked
with r8 == 0, [7] will be considered dead and replaced with "goto -1"
causing hang at runtime.
This patch weaves the callee's explored states onto the callers
parentage chain. Rough parentage for r8 would have looked like this
before:
[0] [1] [2] [3] [4] [5] [10] [11] [6] [7]
| | ,---|----. | | |
sl0: sl0: / sl0: \ sl0: sl0: sl0:
fr0: r8 <-- fr0: r8<+--fr0: r8 `fr0: r8 ,fr0: r8<-fr0: r8
\ fr1: r8 <- fr1: r8 /
\__________________/
after:
[0] [1] [2] [3] [4] [5] [10] [11] [6] [7]
| | | | | |
sl0: sl0: sl0: sl0: sl0: sl0:
fr0: r8 <-- fr0: r8 <- fr0: r8 <- fr0: r8 <-fr0: r8<-fr0: r8
fr1: r8 <- fr1: r8
Now the mark from instruction 6 will travel through callees states.
Note that we don't have to connect r0 because its overwritten by
callees state on return and r1 - r5 because those are not alive
any more once a call is made.
v2:
- don't connect the callees registers twice (Alexei: suggestion & code)
- add more details to the comment (Ed & Alexei)
v1: don't unnecessarily link caller saved regs (Jiong)
Fixes: f4d7e40a5b71 ("bpf: introduce function calls (verification)")
Reported-by: David Beckett <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>
Reviewed-by: Jiong Wang <[email protected]>
Reviewed-by: Edward Cree <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
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Add an arm64-specific prctl to allow a thread to reinitialize its
pointer authentication keys to random values. This can be useful when
exec() is not used for starting new processes, to ensure that different
processes still have different keys.
Signed-off-by: Kristina Martsenko <[email protected]>
Signed-off-by: Will Deacon <[email protected]>
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Changes v2 -> v3:
1. remove check for bpf_dump_raw_ok().
Changes v1 -> v2:
1. Fix error path as Martin suggested.
This patch adds nr_prog_tags and prog_tags to bpf_prog_info. This is a
reliable way for user space to get tags of all sub programs. Before this
patch, user space need to find sub program tags via kallsyms.
This feature will be used in BPF introspection, where user space queries
information about BPF programs via sys_bpf.
Signed-off-by: Song Liu <[email protected]>
Acked-by: Martin KaFai Lau <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
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The func_info and line_info have the bpf insn offset but
they do not contain kernel address. They will still be useful
for the userspace tool to annotate the xlated insn.
This patch removes the bpf_dump_raw_ok() guard for the
func_info and line_info during bpf_prog_get_info_by_fd().
The guard stays for jited_line_info which contains the kernel
address.
Although this bpf_dump_raw_ok() guard behavior has started since
the earlier func_info patch series, I marked the Fixes tag to the
latest line_info patch series which contains both func_info and
line_info and this patch is fixing for both of them.
Fixes: c454a46b5efd ("bpf: Add bpf_line_info support")
Signed-off-by: Martin KaFai Lau <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
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Two threads can try to fire the irq_sim with different offsets and will
end up fighting for the irq_work asignment. Thomas Gleixner suggested a
solution based on a bitfield where we set a bit for every offset
associated with an interrupt that should be fired and then iterate over
all set bits in the interrupt handler.
This is a slightly modified solution using a bitmap so that we don't
impose a limit on the number of interrupts one can allocate with
irq_sim.
Suggested-by: Thomas Gleixner <[email protected]>
Signed-off-by: Bartosz Golaszewski <[email protected]>
Signed-off-by: Marc Zyngier <[email protected]>
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git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"While running various ftrace tests on new development code, the
kmemleak detector found some allocations that were not freed
correctly.
This fixes a couple of leaks in the event trigger code as well as in
adding function trace filters in trace instances"
* tag 'trace-v4.20-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Fix memory leak of instance function hash filters
tracing: Fix memory leak in set_trigger_filter()
tracing: Fix memory leak in create_filter()
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Implement bpffs pretty printing for cgroup local storage maps
(both shared and per-cpu).
Output example (captured for tools/testing/selftests/bpf/netcnt_prog.c):
Shared:
$ cat /sys/fs/bpf/map_2
# WARNING!! The output is for debug purpose only
# WARNING!! The output format will change
{4294968594,1}: {9999,1039896}
Per-cpu:
$ cat /sys/fs/bpf/map_1
# WARNING!! The output is for debug purpose only
# WARNING!! The output format will change
{4294968594,1}: {
cpu0: {0,0,0,0,0}
cpu1: {0,0,0,0,0}
cpu2: {1,104,0,0,0}
cpu3: {0,0,0,0,0}
}
Signed-off-by: Roman Gushchin <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Acked-by: Martin KaFai Lau <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
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If key_type or value_type are of non-trivial data types
(e.g. structure or typedef), it's not possible to check them without
the additional information, which can't be obtained without a pointer
to the btf structure.
So, let's pass btf pointer to the map_check_btf() callbacks.
Signed-off-by: Roman Gushchin <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Acked-by: Martin KaFai Lau <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
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Use DEFINE_SHOW_ATTRIBUTE macro to simplify the code.
Signed-off-by: Yangtao Li <[email protected]>
Acked-by: Pavel Machek <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
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We can save lines/size by removing print_prefix() with buf == NULL.
This patch makes no functional change.
Link: http://lkml.kernel.org/r/1544521745-11925-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
To: Steven Rostedt <[email protected]>
Cc: [email protected]
Signed-off-by: Tetsuo Handa <[email protected]>
Reviewed-by: Sergey Senozhatsky <[email protected]>
Signed-off-by: Petr Mladek <[email protected]>
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Michael and Sandipan report:
Commit ede95a63b5 introduced a bpf_jit_limit tuneable to limit BPF
JIT allocations. At compile time it defaults to PAGE_SIZE * 40000,
and is adjusted again at init time if MODULES_VADDR is defined.
For ppc64 kernels, MODULES_VADDR isn't defined, so we're stuck with
the compile-time default at boot-time, which is 0x9c400000 when
using 64K page size. This overflows the signed 32-bit bpf_jit_limit
value:
root@ubuntu:/tmp# cat /proc/sys/net/core/bpf_jit_limit
-1673527296
and can cause various unexpected failures throughout the network
stack. In one case `strace dhclient eth0` reported:
setsockopt(5, SOL_SOCKET, SO_ATTACH_FILTER, {len=11, filter=0x105dd27f8},
16) = -1 ENOTSUPP (Unknown error 524)
and similar failures can be seen with tools like tcpdump. This doesn't
always reproduce however, and I'm not sure why. The more consistent
failure I've seen is an Ubuntu 18.04 KVM guest booted on a POWER9
host would time out on systemd/netplan configuring a virtio-net NIC
with no noticeable errors in the logs.
Given this and also given that in near future some architectures like
arm64 will have a custom area for BPF JIT image allocations we should
get rid of the BPF_JIT_LIMIT_DEFAULT fallback / default entirely. For
4.21, we have an overridable bpf_jit_alloc_exec(), bpf_jit_free_exec()
so therefore add another overridable bpf_jit_alloc_exec_limit() helper
function which returns the possible size of the memory area for deriving
the default heuristic in bpf_jit_charge_init().
Like bpf_jit_alloc_exec() and bpf_jit_free_exec(), the new
bpf_jit_alloc_exec_limit() assumes that module_alloc() is the default
JIT memory provider, and therefore in case archs implement their custom
module_alloc() we use MODULES_{END,_VADDR} for limits and otherwise for
vmalloc_exec() cases like on ppc64 we use VMALLOC_{END,_START}.
Additionally, for archs supporting large page sizes, we should change
the sysctl to be handled as long to not run into sysctl restrictions
in future.
Fixes: ede95a63b5e8 ("bpf: add bpf_jit_limit knob to restrict unpriv allocations")
Reported-by: Sandipan Das <[email protected]>
Reported-by: Michael Roth <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Tested-by: Michael Roth <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
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Use DEFINE_SHOW_ATTRIBUTE macro to simplify the code.
Signed-off-by: Yangtao Li <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
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This patch introduces a means for syscalls matched in seccomp to notify
some other task that a particular filter has been triggered.
The motivation for this is primarily for use with containers. For example,
if a container does an init_module(), we obviously don't want to load this
untrusted code, which may be compiled for the wrong version of the kernel
anyway. Instead, we could parse the module image, figure out which module
the container is trying to load and load it on the host.
As another example, containers cannot mount() in general since various
filesystems assume a trusted image. However, if an orchestrator knows that
e.g. a particular block device has not been exposed to a container for
writing, it want to allow the container to mount that block device (that
is, handle the mount for it).
This patch adds functionality that is already possible via at least two
other means that I know about, both of which involve ptrace(): first, one
could ptrace attach, and then iterate through syscalls via PTRACE_SYSCALL.
Unfortunately this is slow, so a faster version would be to install a
filter that does SECCOMP_RET_TRACE, which triggers a PTRACE_EVENT_SECCOMP.
Since ptrace allows only one tracer, if the container runtime is that
tracer, users inside the container (or outside) trying to debug it will not
be able to use ptrace, which is annoying. It also means that older
distributions based on Upstart cannot boot inside containers using ptrace,
since upstart itself uses ptrace to monitor services while starting.
The actual implementation of this is fairly small, although getting the
synchronization right was/is slightly complex.
Finally, it's worth noting that the classic seccomp TOCTOU of reading
memory data from the task still applies here, but can be avoided with
careful design of the userspace handler: if the userspace handler reads all
of the task memory that is necessary before applying its security policy,
the tracee's subsequent memory edits will not be read by the tracer.
Signed-off-by: Tycho Andersen <[email protected]>
CC: Kees Cook <[email protected]>
CC: Andy Lutomirski <[email protected]>
CC: Oleg Nesterov <[email protected]>
CC: Eric W. Biederman <[email protected]>
CC: "Serge E. Hallyn" <[email protected]>
Acked-by: Serge Hallyn <[email protected]>
CC: Christian Brauner <[email protected]>
CC: Tyler Hicks <[email protected]>
CC: Akihiro Suda <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
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The const qualifier causes problems for any code that wants to write to the
third argument of the seccomp syscall, as we will do in a future patch in
this series.
The third argument to the seccomp syscall is documented as void *, so
rather than just dropping the const, let's switch everything to use void *
as well.
I believe this is safe because of 1. the documentation above, 2. there's no
real type information exported about syscalls anywhere besides the man
pages.
Signed-off-by: Tycho Andersen <[email protected]>
CC: Kees Cook <[email protected]>
CC: Andy Lutomirski <[email protected]>
CC: Oleg Nesterov <[email protected]>
CC: Eric W. Biederman <[email protected]>
CC: "Serge E. Hallyn" <[email protected]>
Acked-by: Serge Hallyn <[email protected]>
CC: Christian Brauner <[email protected]>
CC: Tyler Hicks <[email protected]>
CC: Akihiro Suda <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
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In the next patch, we're going to use the sd pointer passed to
__seccomp_filter() as the data to pass to userspace. Except that in some
cases (__seccomp_filter(SECCOMP_RET_TRACE), emulate_vsyscall(), every time
seccomp is inovked on power, etc.) the sd pointer will be NULL in order to
force seccomp to recompute the register data. Previously this recomputation
happened one level lower, in seccomp_run_filters(); this patch just moves
it up a level higher to __seccomp_filter().
Thanks Oleg for spotting this.
Signed-off-by: Tycho Andersen <[email protected]>
CC: Kees Cook <[email protected]>
CC: Andy Lutomirski <[email protected]>
CC: Oleg Nesterov <[email protected]>
CC: Eric W. Biederman <[email protected]>
CC: "Serge E. Hallyn" <[email protected]>
Acked-by: Serge Hallyn <[email protected]>
CC: Christian Brauner <[email protected]>
CC: Tyler Hicks <[email protected]>
CC: Akihiro Suda <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
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The following commands will cause a memory leak:
# cd /sys/kernel/tracing
# mkdir instances/foo
# echo schedule > instance/foo/set_ftrace_filter
# rmdir instances/foo
The reason is that the hashes that hold the filters to set_ftrace_filter and
set_ftrace_notrace are not freed if they contain any data on the instance
and the instance is removed.
Found by kmemleak detector.
Cc: [email protected]
Fixes: 591dffdade9f ("ftrace: Allow for function tracing instance to filter functions")
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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When create_event_filter() fails in set_trigger_filter(), the filter may
still be allocated and needs to be freed. The caller expects the
data->filter to be updated with the new filter, even if the new filter
failed (we could add an error message by setting set_str parameter of
create_event_filter(), but that's another update).
But because the error would just exit, filter was left hanging and
nothing could free it.
Found by kmemleak detector.
Cc: [email protected]
Fixes: bac5fb97a173a ("tracing: Add and use generic set_trigger_filter() implementation")
Reviewed-by: Tom Zanussi <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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The create_filter() calls create_filter_start() which allocates a
"parse_error" descriptor, but fails to call create_filter_finish() that
frees it.
The op_stack and inverts in predicate_parse() were also not freed.
Found by kmemleak detector.
Cc: [email protected]
Fixes: 80765597bc587 ("tracing: Rewrite filter logic to be simpler and faster")
Reviewed-by: Tom Zanussi <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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If an Energy Model (EM) is available and if the system isn't
overutilized, re-route waking tasks into an energy-aware placement
algorithm. The selection of an energy-efficient CPU for a task
is achieved by estimating the impact on system-level active energy
resulting from the placement of the task on the CPU with the highest
spare capacity in each performance domain. This strategy spreads tasks
in a performance domain and avoids overly aggressive task packing. The
best CPU energy-wise is then selected if it saves a large enough amount
of energy with respect to prev_cpu.
Although it has already shown significant benefits on some existing
targets, this approach cannot scale to platforms with numerous CPUs.
This is an attempt to do something useful as writing a fast heuristic
that performs reasonably well on a broad spectrum of architectures isn't
an easy task. As such, the scope of usability of the energy-aware
wake-up path is restricted to systems with the SD_ASYM_CPUCAPACITY flag
set, and where the EM isn't too complex.
Signed-off-by: Quentin Perret <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
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Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
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In preparation for the definition of an energy-aware wakeup path,
introduce a helper function to estimate the consequence on system energy
when a specific task wakes-up on a specific CPU. compute_energy()
estimates the capacity state to be reached by all performance domains
and estimates the consumption of each online CPU according to its Energy
Model and its percentage of busy time.
Signed-off-by: Quentin Perret <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
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Cc: [email protected]
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Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
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Energy-aware scheduling is only meant to be active while the system is
_not_ over-utilized. That is, there are spare cycles available to shift
tasks around based on their actual utilization to get a more
energy-efficient task distribution without depriving any tasks. When
above the tipping point task placement is done the traditional way based
on load_avg, spreading the tasks across as many cpus as possible based
on priority scaled load to preserve smp_nice. Below the tipping point we
want to use util_avg instead. We need to define a criteria for when we
make the switch.
The util_avg for each cpu converges towards 100% regardless of how many
additional tasks we may put on it. If we define over-utilized as:
sum_{cpus}(rq.cfs.avg.util_avg) + margin > sum_{cpus}(rq.capacity)
some individual cpus may be over-utilized running multiple tasks even
when the above condition is false. That should be okay as long as we try
to spread the tasks out to avoid per-cpu over-utilization as much as
possible and if all tasks have the _same_ priority. If the latter isn't
true, we have to consider priority to preserve smp_nice.
For example, we could have n_cpus nice=-10 util_avg=55% tasks and
n_cpus/2 nice=0 util_avg=60% tasks. Balancing based on util_avg we are
likely to end up with nice=-10 tasks sharing cpus and nice=0 tasks
getting their own as we 1.5*n_cpus tasks in total and 55%+55% is less
over-utilized than 55%+60% for those cpus that have to be shared. The
system utilization is only 85% of the system capacity, but we are
breaking smp_nice.
To be sure not to break smp_nice, we have defined over-utilization
conservatively as when any cpu in the system is fully utilized at its
highest frequency instead:
cpu_rq(any).cfs.avg.util_avg + margin > cpu_rq(any).capacity
IOW, as soon as one cpu is (nearly) 100% utilized, we switch to load_avg
to factor in priority to preserve smp_nice.
With this definition, we can skip periodic load-balance as no cpu has an
always-running task when the system is not over-utilized. All tasks will
be periodic and we can balance them at wake-up. This conservative
condition does however mean that some scenarios that could benefit from
energy-aware decisions even if one cpu is fully utilized would not get
those benefits.
For systems where some cpus might have reduced capacity on some cpus
(RT-pressure and/or big.LITTLE), we want periodic load-balance checks as
soon a just a single cpu is fully utilized as it might one of those with
reduced capacity and in that case we want to migrate it.
[ peterz: Added a comment explaining why new tasks are not accounted during
overutilization detection. ]
Signed-off-by: Morten Rasmussen <[email protected]>
Signed-off-by: Quentin Perret <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
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Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
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In preparation for the introduction of a new root domain flag which can
be set during load balance (the 'overutilized' flag), clean-up the set
of parameters passed to update_sg_lb_stats(). More specifically, the
'local_group' and 'local_idx' parameters can be removed since they can
easily be reconstructed from within the function.
While at it, transform the 'overload' parameter into a flag stored in
the 'sg_status' parameter hence facilitating the definition of new flags
when needed.
Suggested-by: Peter Zijlstra <[email protected]>
Suggested-by: Valentin Schneider <[email protected]>
Signed-off-by: Quentin Perret <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
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Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
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In order to make sure Energy Aware Scheduling (EAS) will not impact
systems where no Energy Model is available, introduce a static key
guarding the access to EAS code. Since EAS is enabled on a
per-root-domain basis, the static key is enabled when at least one root
domain meets all conditions for EAS.
Signed-off-by: Quentin Perret <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
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Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
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Energy Aware Scheduling (EAS) is designed with the assumption that
frequencies of CPUs follow their utilization value. When using a CPUFreq
governor other than schedutil, the chances of this assumption being true
are small, if any. When schedutil is being used, EAS' predictions are at
least consistent with the frequency requests. Although those requests
have no guarantees to be honored by the hardware, they should at least
guide DVFS in the right direction and provide some hope in regards to the
EAS model being accurate.
To make sure EAS is only used in a sane configuration, create a strong
dependency on schedutil being used. Since having sugov compiled-in does
not provide that guarantee, make CPUFreq call a scheduler function on
governor changes hence letting it rebuild the scheduling domains, check
the governors of the online CPUs, and enable/disable EAS accordingly.
Signed-off-by: Quentin Perret <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
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Cc: [email protected]
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
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Energy Aware Scheduling (EAS) in its current form is most relevant on
platforms with asymmetric CPU topologies (e.g. Arm big.LITTLE) since
this is where there is a lot of potential for saving energy through
scheduling. This is particularly true since the Energy Model only
includes the active power costs of CPUs, hence not providing enough data
to compare packing-vs-spreading strategies.
As such, disable EAS on root domains where the SD_ASYM_CPUCAPACITY flag
is not set. While at it, disable EAS on systems where the complexity of
the Energy Model is too high since that could lead to unacceptable
scheduling overhead.
All in all, EAS can be used on a root domain if and only if:
1. an Energy Model is available;
2. the root domain has an asymmetric CPU capacity topology;
3. the complexity of the root domain's EM is low enough to keep
scheduling overheads low.
Signed-off-by: Quentin Perret <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
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Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
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Add another member to the family of per-cpu sched_domain shortcut
pointers. This one, sd_asym_cpucapacity, points to the lowest level
at which the SD_ASYM_CPUCAPACITY flag is set. While at it, rename the
sd_asym shortcut to sd_asym_packing to avoid confusions.
Generally speaking, the largest opportunity to save energy via
scheduling comes from a smarter exploitation of heterogeneous platforms
(i.e. big.LITTLE). Consequently, the sd_asym_cpucapacity shortcut will
be used at first as the lowest domain where Energy-Aware Scheduling
(EAS) should be applied. For example, it is possible to apply EAS within
a socket on a multi-socket system, as long as each socket has an
asymmetric topology. Energy-aware cross-sockets wake-up balancing will
only happen when the system is over-utilized, or this_cpu and prev_cpu
are in different sockets.
Suggested-by: Morten Rasmussen <[email protected]>
Signed-off-by: Quentin Perret <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
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Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
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The existing scheduling domain hierarchy is defined to map to the cache
topology of the system. However, Energy Aware Scheduling (EAS) requires
more knowledge about the platform, and specifically needs to know about
the span of Performance Domains (PD), which do not always align with
caches.
To address this issue, use the Energy Model (EM) of the system to extend
the scheduler topology code with a representation of the PDs, alongside
the scheduling domains. More specifically, a linked list of PDs is
attached to each root domain. When multiple root domains are in use,
each list contains only the PDs covering the CPUs of its root domain. If
a PD spans over CPUs of multiple different root domains, it will be
duplicated in all lists.
The lists are fully maintained by the scheduler from
partition_sched_domains() in order to cope with hotplug and cpuset
changes. As for scheduling domains, the list are protected by RCU to
ensure safe concurrent updates.
Signed-off-by: Quentin Perret <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
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Cc: [email protected]
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
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Several subsystems in the kernel (task scheduler and/or thermal at the
time of writing) can benefit from knowing about the energy consumed by
CPUs. Yet, this information can come from different sources (DT or
firmware for example), in different formats, hence making it hard to
exploit without a standard API.
As an attempt to address this, introduce a centralized Energy Model
(EM) management framework which aggregates the power values provided
by drivers into a table for each performance domain in the system. The
power cost tables are made available to interested clients (e.g. task
scheduler or thermal) via platform-agnostic APIs. The overall design
is represented by the diagram below (focused on Arm-related drivers as
an example, but applicable to any architecture):
+---------------+ +-----------------+ +-------------+
| Thermal (IPA) | | Scheduler (EAS) | | Other |
+---------------+ +-----------------+ +-------------+
| | em_pd_energy() |
| | em_cpu_get() |
+-----------+ | +--------+
| | |
v v v
+---------------------+
| |
| Energy Model |
| |
| Framework |
| |
+---------------------+
^ ^ ^
| | | em_register_perf_domain()
+----------+ | +---------+
| | |
+---------------+ +---------------+ +--------------+
| cpufreq-dt | | arm_scmi | | Other |
+---------------+ +---------------+ +--------------+
^ ^ ^
| | |
+--------------+ +---------------+ +--------------+
| Device Tree | | Firmware | | ? |
+--------------+ +---------------+ +--------------+
Drivers (typically, but not limited to, CPUFreq drivers) can register
data in the EM framework using the em_register_perf_domain() API. The
calling driver must provide a callback function with a standardized
signature that will be used by the EM framework to build the power
cost tables of the performance domain. This design should offer a lot of
flexibility to calling drivers which are free of reading information
from any location and to use any technique to compute power costs.
Moreover, the capacity states registered by drivers in the EM framework
are not required to match real performance states of the target. This
is particularly important on targets where the performance states are
not known by the OS.
The power cost coefficients managed by the EM framework are specified in
milli-watts. Although the two potential users of those coefficients (IPA
and EAS) only need relative correctness, IPA specifically needs to
compare the power of CPUs with the power of other components (GPUs, for
example), which are still expressed in absolute terms in their
respective subsystems. Hence, specifying the power of CPUs in
milli-watts should help transitioning IPA to using the EM framework
without introducing new problems by keeping units comparable across
sub-systems.
On the longer term, the EM of other devices than CPUs could also be
managed by the EM framework, which would enable to remove the absolute
unit. However, this is not absolutely required as a first step, so this
extension of the EM framework is left for later.
On the client side, the EM framework offers APIs to access the power
cost tables of a CPU (em_cpu_get()), and to estimate the energy
consumed by the CPUs of a performance domain (em_pd_energy()). Clients
such as the task scheduler can then use these APIs to access the shared
data structures holding the Energy Model of CPUs.
Signed-off-by: Quentin Perret <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
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Cc: [email protected]
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Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
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Schedutil requests frequency by aggregating utilization signals from
the scheduler (CFS, RT, DL, IRQ) and applying a 25% margin on top of
them. Since Energy Aware Scheduling (EAS) needs to be able to predict
the frequency requests, it needs to forecast the decisions made by the
governor.
In order to prepare the introduction of EAS, introduce
schedutil_freq_util() to centralize the aforementioned signal
aggregation and make it available to both schedutil and EAS. Since
frequency selection and energy estimation still need to deal with RT and
DL signals slightly differently, schedutil_freq_util() is called with a
different 'type' parameter in those two contexts, and returns an
aggregated utilization signal accordingly. While at it, introduce the
map_util_freq() function which is designed to make schedutil's 25%
margin usable easily for both sugov and EAS.
As EAS will be able to predict schedutil's frequency requests more
accurately than any other governor by design, it'd be sensible to make
sure EAS cannot be used without schedutil. This will be done later, once
EAS has actually been introduced.
Suggested-by: Peter Zijlstra <[email protected]>
Signed-off-by: Quentin Perret <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
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Cc: [email protected]
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Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
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