Replace ternary (condition ? "true" : "false") expressions with the
str_true_false() helper from string_choices.h. This improves readability
by replacing the three-operand ternary with a single function call,
ensures consistent string output, and allows potential string
deduplication by the linker, resulting in a slightly smaller binary.
Link: https://lkml.kernel.org/r/20250814095033.244034-1-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Cc: Kuan-Wei Chiu <visitorckw@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "ida: Remove the ida_simple_xxx() API", v3.
These are the final steps in removing the ida_simple_xxx() API.
This series was last proposed in August 2024. Since then, some users of
the old API have be re-introduced and then removed.
A first time in drivers/misc/rpmb-core.c, added in commit 1e9046e3a1
("rpmb: add Replay Protected Memory Block (RPMB) subsystem") (2024-08-26)
and removed in commit dfc881abca ("rpmb: Remove usage of the deprecated
ida_simple_xx() API") (2024-10-13).
A second time in drivers/gpio/gpio-mpsse.c, added in commit c46a74ff05
("gpio: add support for FTDI's MPSSE as GPIO") (2024-10-14) and removed in
commit f57c084928 (gpio: mpsse: Remove usage of the deprecated
ida_simple_xx() API) (2024-11-22).
Since then, I've not spotted any new usage.
So things being stable now, it's time to end this story once and for all.
This patch (of 3):
ida_alloc() and ida_free() should be preferred to the deprecated
ida_simple_get() and ida_simple_remove().
Note that the upper limit of ida_simple_get() is exclusive, but the one of
ida_alloc_range()/ida_alloc_max() is inclusive. But because of the ranges
used for the tests, there is no need to adjust them.
While at it remove some useless {}.
Link: https://lkml.kernel.org/r/cover.1752480043.git.christophe.jaillet@wanadoo.fr
Link: https://lkml.kernel.org/r/2904fa2006e4fe58eea63aef87fa7f832c7804a1.1752480043.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
KCOV Remote uses two separate memory buffers, one private to the kernel
space (kcov_remote_areas) and the second one shared between user and
kernel space (kcov->area). After every pair of kcov_remote_start() and
kcov_remote_stop(), the coverage data collected in the kcov_remote_areas
is copied to kcov->area so the user can read the collected coverage data.
This memcpy() is located in kcov_move_area().
The load/store pattern on the kernel-side [1] is:
```
/* dst_area === kcov->area, dst_area[0] is where the count is stored */
dst_len = READ_ONCE(*(unsigned long *)dst_area);
...
memcpy(dst_entries, src_entries, ...);
...
WRITE_ONCE(*(unsigned long *)dst_area, dst_len + entries_moved);
```
And for the user [2]:
```
/* cover is equivalent to kcov->area */
n = __atomic_load_n(&cover[0], __ATOMIC_RELAXED);
```
Without a write-memory barrier, the atomic load for the user can
potentially read fresh values of the count stored at cover[0], but
continue to read stale coverage data from the buffer itself. Hence, we
recommend adding a write-memory barrier between the memcpy() and the
WRITE_ONCE() in kcov_move_area().
Link: https://lkml.kernel.org/r/20250728184318.1839137-1-soham.bagchi@utah.edu
Link: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/kernel/kcov.c?h=master#n978 [1]
Link: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/Documentation/dev-tools/kcov.rst#n364 [2]
Signed-off-by: Soham Bagchi <soham.bagchi@utah.edu>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Currently, the kexec_file_load syscall on x86 does not support passing a
device tree blob to the new kernel. Some embedded x86 systems use device
trees. On these systems, failing to pass a device tree to the new kernel
causes a boot failure.
To add support for this, we copy the behavior of ARM64 and PowerPC and
copy the current boot's device tree blob for use in the new kernel. We do
this on x86 by passing the device tree blob as a setup_data entry in
accordance with the x86 boot protocol.
This behavior is gated behind the KEXEC_FILE_FORCE_DTB flag.
Link: https://lkml.kernel.org/r/20250805211527.122367-3-makb@juniper.net
Signed-off-by: Brian Mak <makb@juniper.net>
Cc: Alexander Graf <graf@amazon.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Dave Young <dyoung@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Saravana Kannan <saravanak@google.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull erofs fixes from Gao Xiang:
- Fix invalid algorithm dereference in encoded extents
- Add missing dax_break_layout_final(), since recent FSDAX fixes
didn't cover EROFS
- Arrange long xattr name prefixes more properly
* tag 'erofs-for-6.17-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs:
erofs: fix long xattr name prefix placement
erofs: fix runtime warning on truncate_folio_batch_exceptionals()
erofs: fix invalid algorithm for encoded extents
Patch series "maple_tree: Fix testing for 32bit compiles".
The maple tree test suite supports 32bit builds which causes 32bit nodes
and index/last values. Some tests have too large values and must be
skipped while others depend on certain actions causing the tree to be
altered in another measurable way (such as the height decreasing or
increasing).
Two tests were added that broke 32bit testing, either by compile warnings
or failures. These fixes restore the tests to a working order.
Building 32bit version can be done on a 32bit platform, or by using a
command like: BUILD=32 make clean maple
This patch (of 2):
Some tests are invalid on 32bit due to the size of the index and last.
Making those tests depend on the correct build flags stops compile
complaints.
Link: https://lkml.kernel.org/r/20250828003023.418966-1-Liam.Howlett@oracle.com
Link: https://lkml.kernel.org/r/20250828003023.418966-2-Liam.Howlett@oracle.com
Fixes: 5d659bbb52 ("maple_tree: introduce mas_wr_store_type()")
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Calling is_huge_zero_folio(NULL) should not be legal - it makes no sense,
and a different (theoretical) implementation may dereference the pointer.
But currently, lacking any explicit documentation, this call is possible.
But if somebody really passes NULL, the function should not return true -
this isn't the huge zero folio after all! However, if the
`huge_zero_folio` hasn't been allocated yet, it's NULL, and
is_huge_zero_folio(NULL) just happens to return true, which is a lie.
This weird side effect prevented me from reproducing a kernel crash that
occurred when the elements of a folio_batch were NULL - since
folios_put_refs() skips huge zero folios, this sometimes causes a crash,
but sometimes does not. For debugging, it is better to reveal such bugs
reliably and not hide them behind random preconditions like "has the huge
zero folio already been created?"
To improve detection of such bugs, David Hildenbrand suggested adding a
VM_WARN_ON_ONCE().
Link: https://lkml.kernel.org/r/20250828084820.570118-1-max.kellermann@ionos.com
Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Mariano Pache <npache@redhat.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The shared userspace logic used for unit-testing maple tree and VMA code
currently has its own replacements for atomics helpers. This is not
needed as the necessary APIs already have userspace implementations in the
tools tree. Switching over to that allows deleting a bit of code.
Note that the implementation is different; while the version being deleted
here is implemented using liburcu, the existing version in tools uses
either x86 asm or compiler builtins. It's assumed that both are equally
likely to be correct.
The tools tree's version of atomic_t is a struct type while the version
being deleted was just a typedef of an integer. This means it's no longer
valid to call __sync_bool_compare_and_swap() directly on it. One option
would be to just peek into the struct and call it on the field, but it
seems a little cleaner to just use the corresponding atomic.h API whic has
been added recently. Now the fake mapping_map_writable() is copied from
the real one.
Link: https://lkml.kernel.org/r/20250828-b4-vma-no-atomic-h-v2-4-02d146a58ed2@google.com
Signed-off-by: Brendan Jackman <jackmanb@google.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Cc: Jann Horn <jannh@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "tools: testing: Use existing atomic.h for vma/maple tests",
v2.
De-duplicating this lets us delete a bit of code.
Ulterior motive: I'm working on a new set of the userspace-based unit
tests, which will need the atomics API too. That would involve even more
duplication, so while the win in this patchset alone is very minimal, it
looks a lot more significant with my other WIP patchset.
I've tested these commands:
make -C tools/testing/vma -j
tools/testing/vma/vma
make -C tools/testing/radix-tree -j
tools/testing/radix-tree/maple
Note the EXTRA_CFLAGS patch is actually orthogonal, let me know if you'd
prefer I send it separately.
This patch (of 4):
The VMA tests need an operation equivalent to atomic_inc_unless_negative()
to implement a fake mapping_map_writable(). Adding it will enable them to
switch to the shared atomic headers and simplify that fake implementation.
In order to add that, also add atomic_try_cmpxchg() which can be used to
implement it. This is copied from Documentation/atomic_t.txt. Then,
implement atomic_inc_unless_negative() itself based on the
raw_atomic_dec_unless_positive() in
include/linux/atomic/atomic-arch-fallback.h.
There's no present need for a highly-optimised version of this (nor any
reason to think this implementation is sub-optimal on x86) so just
implement this with generic C, no x86-specifics.
Link: https://lkml.kernel.org/r/20250828-b4-vma-no-atomic-h-v2-0-02d146a58ed2@google.com
Link: https://lkml.kernel.org/r/20250828-b4-vma-no-atomic-h-v2-1-02d146a58ed2@google.com
Signed-off-by: Brendan Jackman <jackmanb@google.com>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Cc: Jann Horn <jannh@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm/damon: support ARM32 with LPAE", v3.
Previously, DAMON's physical address space monitoring only supported
memory ranges below 4GB on LPAE-enabled systems. This was due to the use
of 'unsigned long' in 'struct damon_addr_range', which is 32-bit on ARM32
even with LPAE enabled[1].
To add DAMON support for ARM32 with LPAE enabled, a new core layer
parameter called 'addr_unit' was introduced[2]. Operations set layer can
translate a core layer address to the real address by multiplying the
parameter value to the core layer address. Support of the parameter is up
to each operations layer implementation, though. For example, operations
set implementations for virtual address space can simply ignore the
parameter. Add the support on paddr, which is the DAMON operations set
implementation for the physical address space, as we have a clear use case
for that.
This patch (of 11):
In some cases, some of the real address that handled by the underlying
operations set cannot be handled by DAMON since it uses only 'unsinged
long' as the address type. Using DAMON for physical address space
monitoring of 32 bit ARM devices with large physical address extension
(LPAE) is one example[1].
Add a parameter name 'addr_unit' to core layer to help such cases. DAMON
core API callers can set it as the scale factor that will be used by the
operations set for translating the core layer's addresses to the real
address by multiplying the parameter value to the core layer address.
Support of the parameter is up to each operations set layer. The support
from the physical address space operations set (paddr) will be added with
following commits.
Link: https://lkml.kernel.org/r/20250828171242.59810-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20250828171242.59810-2-sj@kernel.org
Link: https://lore.kernel.org/20250408075553.959388-1-zuoze1@huawei.com [1]
Link: https://lore.kernel.org/all/20250416042551.158131-1-sj@kernel.org/ [2]
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Quanmin Yan <yanquanmin1@huawei.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: ze zuo <zuoze1@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
enum pageblock_bits defines the meaning of pageblock bits. Currently
PB_migratetype_bits says the lowest 3 bits represents migratetype and
PB_migrate_end/MIGRATETYPE_MASK's definition rely on it with magical
computation.
Remove the definition of PB_migratetype_bits/PB_migrate_end. Use
PB_migrate_[0|1|2] to represent lowest bits for migratetype. Then we can
simplify related definition.
Also, MIGRATETYPE_AND_ISO_MASK is MIGRATETYPE_MASK add isolation bit. Use
MIGRATETYPE_MASK in the definition of MIGRATETYPE_AND_ISO_MASK looks
cleaner.
No functional change intended.
Link: https://lkml.kernel.org/r/20250827070105.16864-3-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "introduce kernel file mapped folios", v4.
Btrfs currently tracks its metadata pages in the page cache, using a fake
inode (fs_info->btree_inode) with offsets corresponding to where the
metadata is stored in the filesystem's full logical address space.
A consequence of this is that when btrfs uses filemap_add_folio(), this
usage is charged to the cgroup of whichever task happens to be running at
the time. These folios don't belong to any particular user cgroup, so I
don't think it makes much sense for them to be charged in that way. Some
negative consequences as a result:
- A task can be holding some important btrfs locks, then need to lookup
some metadata and go into reclaim, extending the duration it holds
that lock for, and unfairly pushing its own reclaim pain onto other
cgroups.
- If that cgroup goes into reclaim, it might reclaim these folios a
different non-reclaiming cgroup might need soon. This is naturally
offset by LRU reclaim, but still.
We have two options for how to manage such file pages:
1. charge them to the root cgroup.
2. don't charge them to any cgroup at all.
2. breaks the invariant that every mapped page has a cgroup. This is
workable, but unnecessarily risky. Therefore, go with 1.
A very similar proposal to use the root cgroup was previously made by Qu,
where he eventually proposed the idea of setting it per address_space.
This makes good sense for the btrfs use case, as the behavior should apply
to all use of the address_space, not select allocations. I.e., if someone
adds another filemap_add_folio() call using btrfs's btree_inode, we would
almost certainly want to account that to the root cgroup as well.
This patch (of 3):
Add the flag AS_KERNEL_FILE to the address_space to indicate that this
mapping's memory is exempt from the usual memcg accounting.
[boris@bur.io: fix CONFIG_MEMCG build for AS_KERNEL_FILE]
Link: https://lkml.kernel.org/r/6de59ddeec81b5c294d337c001ba0061631d4ec6.1755816635.git.boris@bur.io
Link: https://lore.kernel.org/linux-mm/b5fef5372ae454a7b6da4f2f75c427aeab6a07d6.1727498749.git.wqu@suse.com/
Link: https://lkml.kernel.org/r/f09c4e2c90351d4cb30a1969f7a863b9238bd291.1755812945.git.boris@bur.io
Signed-off-by: Boris Burkov <boris@bur.io>
Suggested-by: Qu Wenruo <wqu@suse.com>
Suggested-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "selftests/mm: uffd-stress fixes", v2.
This patchset ensures that the number of hugepages is correctly set in the
system so that the uffd-stress test does not fail due to the racy nature
of the test. Patch 1 changes the hugepage constraint in the
run_vmtests.sh script, whereas patch 2 changes the constraint in the test
itself.
This patch (of 2):
We observed uffd-stress selftest failure on arm64 and intermittent
failures on x86 too:
running ./uffd-stress hugetlb-private 128 32
bounces: 17, mode: rnd read, ERROR: UFFDIO_COPY error: -12 (errno=12, @uffd-common.c:617) [FAIL]
not ok 18 uffd-stress hugetlb-private 128 32 # exit=1
For this particular case, the number of free hugepages from run_vmtests.sh
will be 128, and the test will allocate 64 hugepages in the source
location. The stress() function will start spawning threads which will
operate on the destination location, triggering uffd-operations like
UFFDIO_COPY from src to dst, which means that we will require 64 more
hugepages for the dst location.
Let us observe the locking_thread() function. It will lock the mutex kept
at dst, triggering uffd-copy. Suppose that 127 (64 for src and 63 for
dst) hugepages have been reserved. In case of BOUNCE_RANDOM, it may
happen that two threads trying to lock the mutex at dst, try to do so at
the same hugepage number. If one thread succeeds in reserving the last
hugepage, then the other thread may fail in alloc_hugetlb_folio(),
returning -ENOMEM. I can confirm that this is indeed the case by this
hacky patch:
:--- a/mm/hugetlb.c
; +++ b/mm/hugetlb.c
; @@ -6929,6 +6929,11 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
;
; folio = alloc_hugetlb_folio(dst_vma, dst_addr, false);
; if (IS_ERR(folio)) {
; + pte_t *actual_pte = hugetlb_walk(dst_vma, dst_addr, PMD_SIZE);
; + if (actual_pte) {
; + ret = -EEXIST;
; + goto out;
; + }
; ret = -ENOMEM;
; goto out;
; }
This code path gets triggered indicating that the PMD at which one thread
is trying to map a hugepage, gets filled by a racing thread.
Therefore, instead of using freepgs to compute the amount of memory, use
freepgs - (min(32, nr_cpus) - 1), so that the test still has some extra
hugepages to use. The adjustment is a function of min(32, nr_cpus) - the
value of nr_parallel in the test - because in the worst case, nr_parallel
number of threads will try to map a hugepage on the same PMD, one will win
the allocation race, and the other nr_parallel - 1 threads will fail, so
we need extra nr_parallel - 1 hugepages to satisfy this request. Note
that, in case the adjusted value underflows, there is a check for the
number of free hugepages in the test itself, which will fail:
get_free_hugepages() < bytes / page_size A negative value will be passed
on to bytes which is of type size_t, thus the RHS will become a large
value and the check will fail, so we are safe.
Link: https://lkml.kernel.org/r/20250909061531.57272-1-dev.jain@arm.com
Link: https://lkml.kernel.org/r/20250909061531.57272-2-dev.jain@arm.com
Signed-off-by: Dev Jain <dev.jain@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mariano Pache <npache@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When specifying fixed sized scratch areas, the parser only parses the
three scratch sizes and ignores the rest of the argument. This means the
argument can have any bogus trailing characters.
For example, "kho_scratch=256M,512M,512Mfoobar" results in successful
parsing:
[ 0.000000] KHO: scratch areas: lowmem: 256MiB global: 512MiB pernode: 512MiB
It is generally a good idea to parse arguments as strictly as possible.
In addition, if bogus trailing characters are allowed in the kho_scratch
argument, it is possible that some people might end up using them and
later extensions to the argument format will cause unexpected breakages.
Make sure the argument is fully consumed after all three scratch sizes are
parsed. With this change, the bogus argument
"kho_scratch=256M,512M,512Mfoobar" results in:
[ 0.000000] Malformed early option 'kho_scratch'
Link: https://lkml.kernel.org/r/20250826123817.64681-1-pratyush@kernel.org
Signed-off-by: Pratyush Yadav <pratyush@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Alexander Graf <graf@amazon.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Changyuan Lyu <changyuanl@google.com>
Cc: Pratyush Yadav <pratyush@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kuan-Wei Chiu
Thorsten Blum
Tetsuo Handa
Xichao Zhao
Joe Perches
Huacai Chen
Liao Yuanhong
Christophe JAILLET
Soham Bagchi
Qianfeng Rong
Brian Mak
Masami Hiramatsu (Google)
Linus Torvalds
Liam R. Howlett
Max Kellermann
Wei Yang
Brendan Jackman
Quanmin Yan
SeongJae Park
Boris Burkov
Miaohe Lin
Dev Jain
Baolin Wang
Sidhartha Kumar
Pratyush Yadav
Wander Lairson Costa