[PATCH 00/44] Change a lot of min_t() that might mask high bits

[PATCH 00/44] Change a lot of min_t() that might mask high bits

[david.laight.linux]

From: David Laight <david.laight.linux@gmail.com>

It in not uncommon for code to use min_t(uint, a, b) when one of a or b
is 64bit and can have a value that is larger than 2^32;
This is particularly prevelant with:
	uint_var = min_t(uint, uint_var, uint64_expression);

Casts to u8 and u16 are very likely to discard significant bits.

These can be detected at compile time by changing min_t(), for example:
#define CHECK_SIZE(fn, type, val) \
	BUILD_BUG_ON_MSG(sizeof (val) > sizeof (type) && \
		!statically_true(((val) >> 8 * (sizeof (type) - 1)) < 256), \
		fn "() significant bits of '" #val "' may be discarded")

#define min_t(type, x, y) ({ \
	CHECK_SIZE("min_t", type, x); \
	CHECK_SIZE("min_t", type, y); \
	__cmp_once(min, type, x, y); })

(and similar changes to max_t() and clamp_t().)

This shows up some real bugs, some unlikely bugs and some false positives.
In most cases both arguments are unsigned type (just different ones)
and min_t() can just be replaced by min().

The patches are all independant and are most of the ones needed to
get the x86-64 kernel I build to compile.
I've not tried building an allyesconfig or allmodconfig kernel.
I've also not included the patch to minmax.h itself.

I've tried to put the patches that actually fix things first.
The last one is 0009.

I gave up on fixing sched/fair.c - it is too broken for a single patch!
The patch for net/ipv4/tcp.c is also absent because do_tcp_getsockopt()
needs multiple/larger changes to make it 'sane'.

I've had to trim the 124 maintainers/lists that get_maintainer.pl finds
from 124 to under 100 to be able to send the cover letter.
The individual patches only go to the addresses found for the associated files.
That reduces the number of emails to a less unsane number.

David Laight (44):
  x86/asm/bitops: Change the return type of variable__ffs() to unsigned
    int
  ext4: Fix saturation of 64bit inode times for old filesystems
  perf: Fix branch stack callchain limit
  io_uring/net: Change some dubious min_t()
  ipc/msg: Fix saturation of percpu counts in msgctl_info()
  bpf: Verifier, remove some unusual uses of min_t() and max_t()
  net/core/flow_dissector: Fix cap of __skb_flow_dissect() return value.
  net: ethtool: Use min3() instead of nested min_t(u16,...)
  ipv6: __ip6_append_data() don't abuse max_t() casts
  x86/crypto: ctr_crypt() use min() instead of min_t()
  arch/x96/kvm: use min() instead of min_t()
  block: use min() instead of min_t()
  drivers/acpi: use min() instead of min_t()
  drivers/char/hw_random: use min3() instead of nested min_t()
  drivers/char/tpm: use min() instead of min_t()
  drivers/crypto/ccp: use min() instead of min_t()
  drivers/cxl: use min() instead of min_t()
  drivers/gpio: use min() instead of min_t()
  drivers/gpu/drm/amd: use min() instead of min_t()
  drivers/i2c/busses: use min() instead of min_t()
  drivers/net/ethernet/realtek: use min() instead of min_t()
  drivers/nvme: use min() instead of min_t()
  arch/x86/mm: use min() instead of min_t()
  drivers/nvmem: use min() instead of min_t()
  drivers/pci: use min() instead of min_t()
  drivers/scsi: use min() instead of min_t()
  drivers/tty/vt: use umin() instead of min_t(u16, ...) for row/col
    limits
  drivers/usb/storage: use min() instead of min_t()
  drivers/xen: use min() instead of min_t()
  fs: use min() or umin() instead of min_t()
  block: bvec.h: use min() instead of min_t()
  nodemask: use min() instead of min_t()
  ipc: use min() instead of min_t()
  bpf: use min() instead of min_t()
  bpf_trace: use min() instead of min_t()
  lib/bucket_locks: use min() instead of min_t()
  lib/crypto/mpi: use min() instead of min_t()
  lib/dynamic_queue_limits: use max() instead of max_t()
  mm: use min() instead of min_t()
  net: Don't pass bitfields to max_t()
  net/core: Change loop conditions so min() can be used
  net: use min() instead of min_t()
  net/netlink: Use umin() to avoid min_t(int, ...) discarding high bits
  net/mptcp: Change some dubious min_t(int, ...) to min()

 arch/x86/crypto/aesni-intel_glue.c            |  3 +-
 arch/x86/include/asm/bitops.h                 | 18 +++++-------
 arch/x86/kvm/emulate.c                        |  3 +-
 arch/x86/kvm/lapic.c                          |  2 +-
 arch/x86/kvm/mmu/mmu.c                        |  2 +-
 arch/x86/mm/pat/set_memory.c                  | 12 ++++----
 block/blk-iocost.c                            |  6 ++--
 block/blk-settings.c                          |  2 +-
 block/partitions/efi.c                        |  3 +-
 drivers/acpi/property.c                       |  2 +-
 drivers/char/hw_random/core.c                 |  2 +-
 drivers/char/tpm/tpm1-cmd.c                   |  2 +-
 drivers/char/tpm/tpm_tis_core.c               |  4 +--
 drivers/crypto/ccp/ccp-dev.c                  |  2 +-
 drivers/cxl/core/mbox.c                       |  2 +-
 drivers/gpio/gpiolib-acpi-core.c              |  2 +-
 .../gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c  |  4 +--
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c        |  2 +-
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c |  2 +-
 drivers/i2c/busses/i2c-designware-master.c    |  2 +-
 drivers/net/ethernet/realtek/r8169_main.c     |  3 +-
 drivers/nvme/host/pci.c                       |  3 +-
 drivers/nvme/host/zns.c                       |  3 +-
 drivers/nvmem/core.c                          |  2 +-
 drivers/pci/probe.c                           |  3 +-
 drivers/scsi/hosts.c                          |  2 +-
 drivers/tty/vt/selection.c                    |  9 +++---
 drivers/usb/storage/protocol.c                |  3 +-
 drivers/xen/grant-table.c                     |  2 +-
 fs/buffer.c                                   |  2 +-
 fs/exec.c                                     |  2 +-
 fs/ext4/ext4.h                                |  2 +-
 fs/ext4/mballoc.c                             |  3 +-
 fs/ext4/resize.c                              |  2 +-
 fs/ext4/super.c                               |  2 +-
 fs/fat/dir.c                                  |  4 +--
 fs/fat/file.c                                 |  3 +-
 fs/fuse/dev.c                                 |  2 +-
 fs/fuse/file.c                                |  8 ++---
 fs/splice.c                                   |  2 +-
 include/linux/bvec.h                          |  3 +-
 include/linux/nodemask.h                      |  9 +++---
 include/linux/perf_event.h                    |  2 +-
 include/net/tcp_ecn.h                         |  5 ++--
 io_uring/net.c                                |  6 ++--
 ipc/mqueue.c                                  |  4 +--
 ipc/msg.c                                     |  6 ++--
 kernel/bpf/core.c                             |  4 +--
 kernel/bpf/log.c                              |  2 +-
 kernel/bpf/verifier.c                         | 29 +++++++------------
 kernel/trace/bpf_trace.c                      |  2 +-
 lib/bucket_locks.c                            |  2 +-
 lib/crypto/mpi/mpicoder.c                     |  2 +-
 lib/dynamic_queue_limits.c                    |  2 +-
 mm/gup.c                                      |  4 +--
 mm/memblock.c                                 |  2 +-
 mm/memory.c                                   |  2 +-
 mm/percpu.c                                   |  2 +-
 mm/truncate.c                                 |  3 +-
 mm/vmscan.c                                   |  2 +-
 net/core/datagram.c                           |  6 ++--
 net/core/flow_dissector.c                     |  7 ++---
 net/core/net-sysfs.c                          |  3 +-
 net/core/skmsg.c                              |  4 +--
 net/ethtool/cmis_cdb.c                        |  7 ++---
 net/ipv4/fib_trie.c                           |  2 +-
 net/ipv4/tcp_input.c                          |  4 +--
 net/ipv4/tcp_output.c                         |  5 ++--
 net/ipv4/tcp_timer.c                          |  4 +--
 net/ipv6/addrconf.c                           |  8 ++---
 net/ipv6/ip6_output.c                         |  7 +++--
 net/ipv6/ndisc.c                              |  5 ++--
 net/mptcp/protocol.c                          |  8 ++---
 net/netlink/genetlink.c                       |  9 +++---
 net/packet/af_packet.c                        |  2 +-
 net/unix/af_unix.c                            |  4 +--
 76 files changed, 141 insertions(+), 176 deletions(-)

-- 
2.39.5

[PATCH 03/44] perf: Fix branch stack callchain limit

[david.laight.linux]

From: David Laight <david.laight.linux@gmail.com>

The code that bounds the brs->nr to event->attr.sample_max_stack
incorrectly masks brs->nr with 65535 before the limit check.
Replace the min_t(u16, ...) with a plain min(...).

I guess there may be another limit on brs->nr (which is u64).

Fixes: c53e14f1ea4a8 ("perf: Extend per event callchain limit to branch stack")
Signed-off-by: David Laight <david.laight.linux@gmail.com>
---
 include/linux/perf_event.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index fd1d91017b99..f91c875ea311 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -1430,7 +1430,7 @@ static inline void perf_sample_save_brstack(struct perf_sample_data *data,
 	if (branch_sample_hw_index(event))
 		size += sizeof(u64);
 
-	brs->nr = min_t(u16, event->attr.sample_max_stack, brs->nr);
+	brs->nr = min(event->attr.sample_max_stack, brs->nr);
 
 	size += brs->nr * sizeof(struct perf_branch_entry);
 
-- 
2.39.5

Re: [PATCH 00/44] Change a lot of min_t() that might mask high bits

[Jakub Kicinski]

On Wed, 19 Nov 2025 22:40:56 +0000 david.laight.linux@gmail.com wrote:
> I've had to trim the 124 maintainers/lists that get_maintainer.pl finds
> from 124 to under 100 to be able to send the cover letter.
> The individual patches only go to the addresses found for the associated files.
> That reduces the number of emails to a less unsane number.

Please split the networking (9?) patches out to a separate series.
It will help you with the CC list, and help us to get this applied..

Re: [PATCH 00/44] Change a lot of min_t() that might mask high bits

[Lorenzo Stoakes]

On Wed, Nov 19, 2025 at 10:40:56PM +0000, david.laight.linux@gmail.com wrote:
> From: David Laight <david.laight.linux@gmail.com>
>
> It in not uncommon for code to use min_t(uint, a, b) when one of a or b
> is 64bit and can have a value that is larger than 2^32;
> This is particularly prevelant with:
> 	uint_var = min_t(uint, uint_var, uint64_expression);
>
> Casts to u8 and u16 are very likely to discard significant bits.
>
> These can be detected at compile time by changing min_t(), for example:
> #define CHECK_SIZE(fn, type, val) \
> 	BUILD_BUG_ON_MSG(sizeof (val) > sizeof (type) && \
> 		!statically_true(((val) >> 8 * (sizeof (type) - 1)) < 256), \
> 		fn "() significant bits of '" #val "' may be discarded")
>
> #define min_t(type, x, y) ({ \
> 	CHECK_SIZE("min_t", type, x); \
> 	CHECK_SIZE("min_t", type, y); \
> 	__cmp_once(min, type, x, y); })
>
> (and similar changes to max_t() and clamp_t().)

Have we made sure that the introduction of these don't cause a combinatorial
explosion like previous min()/max() changes did?

>
> This shows up some real bugs, some unlikely bugs and some false positives.
> In most cases both arguments are unsigned type (just different ones)
> and min_t() can just be replaced by min().
>
> The patches are all independant and are most of the ones needed to
> get the x86-64 kernel I build to compile.
> I've not tried building an allyesconfig or allmodconfig kernel.

Well I have a beefy box at my disposal so tried thiese for you :)

Both allyesconfig & allmodconfig works fine for x86-64 (I tried both for good
measure)

> I've also not included the patch to minmax.h itself.
>
> I've tried to put the patches that actually fix things first.
> The last one is 0009.
>
> I gave up on fixing sched/fair.c - it is too broken for a single patch!
> The patch for net/ipv4/tcp.c is also absent because do_tcp_getsockopt()
> needs multiple/larger changes to make it 'sane'.

I guess this isn't broken per se there just retain min_t()/max_t() right?

>
> I've had to trim the 124 maintainers/lists that get_maintainer.pl finds
> from 124 to under 100 to be able to send the cover letter.
> The individual patches only go to the addresses found for the associated files.
> That reduces the number of emails to a less unsane number.
>
> David Laight (44):
>   x86/asm/bitops: Change the return type of variable__ffs() to unsigned
>     int
>   ext4: Fix saturation of 64bit inode times for old filesystems
>   perf: Fix branch stack callchain limit
>   io_uring/net: Change some dubious min_t()
>   ipc/msg: Fix saturation of percpu counts in msgctl_info()
>   bpf: Verifier, remove some unusual uses of min_t() and max_t()
>   net/core/flow_dissector: Fix cap of __skb_flow_dissect() return value.
>   net: ethtool: Use min3() instead of nested min_t(u16,...)
>   ipv6: __ip6_append_data() don't abuse max_t() casts
>   x86/crypto: ctr_crypt() use min() instead of min_t()
>   arch/x96/kvm: use min() instead of min_t()
>   block: use min() instead of min_t()
>   drivers/acpi: use min() instead of min_t()
>   drivers/char/hw_random: use min3() instead of nested min_t()
>   drivers/char/tpm: use min() instead of min_t()
>   drivers/crypto/ccp: use min() instead of min_t()
>   drivers/cxl: use min() instead of min_t()
>   drivers/gpio: use min() instead of min_t()
>   drivers/gpu/drm/amd: use min() instead of min_t()
>   drivers/i2c/busses: use min() instead of min_t()
>   drivers/net/ethernet/realtek: use min() instead of min_t()
>   drivers/nvme: use min() instead of min_t()
>   arch/x86/mm: use min() instead of min_t()
>   drivers/nvmem: use min() instead of min_t()
>   drivers/pci: use min() instead of min_t()
>   drivers/scsi: use min() instead of min_t()
>   drivers/tty/vt: use umin() instead of min_t(u16, ...) for row/col
>     limits
>   drivers/usb/storage: use min() instead of min_t()
>   drivers/xen: use min() instead of min_t()
>   fs: use min() or umin() instead of min_t()
>   block: bvec.h: use min() instead of min_t()
>   nodemask: use min() instead of min_t()
>   ipc: use min() instead of min_t()
>   bpf: use min() instead of min_t()
>   bpf_trace: use min() instead of min_t()
>   lib/bucket_locks: use min() instead of min_t()
>   lib/crypto/mpi: use min() instead of min_t()
>   lib/dynamic_queue_limits: use max() instead of max_t()
>   mm: use min() instead of min_t()
>   net: Don't pass bitfields to max_t()
>   net/core: Change loop conditions so min() can be used
>   net: use min() instead of min_t()
>   net/netlink: Use umin() to avoid min_t(int, ...) discarding high bits
>   net/mptcp: Change some dubious min_t(int, ...) to min()
>
>  arch/x86/crypto/aesni-intel_glue.c            |  3 +-
>  arch/x86/include/asm/bitops.h                 | 18 +++++-------
>  arch/x86/kvm/emulate.c                        |  3 +-
>  arch/x86/kvm/lapic.c                          |  2 +-
>  arch/x86/kvm/mmu/mmu.c                        |  2 +-
>  arch/x86/mm/pat/set_memory.c                  | 12 ++++----
>  block/blk-iocost.c                            |  6 ++--
>  block/blk-settings.c                          |  2 +-
>  block/partitions/efi.c                        |  3 +-
>  drivers/acpi/property.c                       |  2 +-
>  drivers/char/hw_random/core.c                 |  2 +-
>  drivers/char/tpm/tpm1-cmd.c                   |  2 +-
>  drivers/char/tpm/tpm_tis_core.c               |  4 +--
>  drivers/crypto/ccp/ccp-dev.c                  |  2 +-
>  drivers/cxl/core/mbox.c                       |  2 +-
>  drivers/gpio/gpiolib-acpi-core.c              |  2 +-
>  .../gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c  |  4 +--
>  drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c        |  2 +-
>  .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c |  2 +-
>  drivers/i2c/busses/i2c-designware-master.c    |  2 +-
>  drivers/net/ethernet/realtek/r8169_main.c     |  3 +-
>  drivers/nvme/host/pci.c                       |  3 +-
>  drivers/nvme/host/zns.c                       |  3 +-
>  drivers/nvmem/core.c                          |  2 +-
>  drivers/pci/probe.c                           |  3 +-
>  drivers/scsi/hosts.c                          |  2 +-
>  drivers/tty/vt/selection.c                    |  9 +++---
>  drivers/usb/storage/protocol.c                |  3 +-
>  drivers/xen/grant-table.c                     |  2 +-
>  fs/buffer.c                                   |  2 +-
>  fs/exec.c                                     |  2 +-
>  fs/ext4/ext4.h                                |  2 +-
>  fs/ext4/mballoc.c                             |  3 +-
>  fs/ext4/resize.c                              |  2 +-
>  fs/ext4/super.c                               |  2 +-
>  fs/fat/dir.c                                  |  4 +--
>  fs/fat/file.c                                 |  3 +-
>  fs/fuse/dev.c                                 |  2 +-
>  fs/fuse/file.c                                |  8 ++---
>  fs/splice.c                                   |  2 +-
>  include/linux/bvec.h                          |  3 +-
>  include/linux/nodemask.h                      |  9 +++---
>  include/linux/perf_event.h                    |  2 +-
>  include/net/tcp_ecn.h                         |  5 ++--
>  io_uring/net.c                                |  6 ++--
>  ipc/mqueue.c                                  |  4 +--
>  ipc/msg.c                                     |  6 ++--
>  kernel/bpf/core.c                             |  4 +--
>  kernel/bpf/log.c                              |  2 +-
>  kernel/bpf/verifier.c                         | 29 +++++++------------
>  kernel/trace/bpf_trace.c                      |  2 +-
>  lib/bucket_locks.c                            |  2 +-
>  lib/crypto/mpi/mpicoder.c                     |  2 +-
>  lib/dynamic_queue_limits.c                    |  2 +-
>  mm/gup.c                                      |  4 +--
>  mm/memblock.c                                 |  2 +-
>  mm/memory.c                                   |  2 +-
>  mm/percpu.c                                   |  2 +-
>  mm/truncate.c                                 |  3 +-
>  mm/vmscan.c                                   |  2 +-
>  net/core/datagram.c                           |  6 ++--
>  net/core/flow_dissector.c                     |  7 ++---
>  net/core/net-sysfs.c                          |  3 +-
>  net/core/skmsg.c                              |  4 +--
>  net/ethtool/cmis_cdb.c                        |  7 ++---
>  net/ipv4/fib_trie.c                           |  2 +-
>  net/ipv4/tcp_input.c                          |  4 +--
>  net/ipv4/tcp_output.c                         |  5 ++--
>  net/ipv4/tcp_timer.c                          |  4 +--
>  net/ipv6/addrconf.c                           |  8 ++---
>  net/ipv6/ip6_output.c                         |  7 +++--
>  net/ipv6/ndisc.c                              |  5 ++--
>  net/mptcp/protocol.c                          |  8 ++---
>  net/netlink/genetlink.c                       |  9 +++---
>  net/packet/af_packet.c                        |  2 +-
>  net/unix/af_unix.c                            |  4 +--
>  76 files changed, 141 insertions(+), 176 deletions(-)
>
> --
> 2.39.5
>

Re: (subset) [PATCH 00/44] Change a lot of min_t() that might mask high bits

[Jens Axboe]

On Wed, 19 Nov 2025 22:40:56 +0000, david.laight.linux@gmail.com wrote:
> It in not uncommon for code to use min_t(uint, a, b) when one of a or b
> is 64bit and can have a value that is larger than 2^32;
> This is particularly prevelant with:
> 	uint_var = min_t(uint, uint_var, uint64_expression);
> 
> Casts to u8 and u16 are very likely to discard significant bits.
> 
> [...]

Applied, thanks!

[12/44] block: use min() instead of min_t()
        commit: 9420e720ad192c53c8d2803c5a2313b2d586adbd

Best regards,
-- 
Jens Axboe

Re: [PATCH 00/44] Change a lot of min_t() that might mask high bits

[Herbert Xu]

On Wed, Nov 19, 2025 at 10:40:56PM +0000, david.laight.linux@gmail.com wrote:
> From: David Laight <david.laight.linux@gmail.com>
> 
> It in not uncommon for code to use min_t(uint, a, b) when one of a or b
> is 64bit and can have a value that is larger than 2^32;
> This is particularly prevelant with:
> 	uint_var = min_t(uint, uint_var, uint64_expression);
> 
> Casts to u8 and u16 are very likely to discard significant bits.
> 
> These can be detected at compile time by changing min_t(), for example:
> #define CHECK_SIZE(fn, type, val) \
> 	BUILD_BUG_ON_MSG(sizeof (val) > sizeof (type) && \
> 		!statically_true(((val) >> 8 * (sizeof (type) - 1)) < 256), \
> 		fn "() significant bits of '" #val "' may be discarded")
> 
> #define min_t(type, x, y) ({ \
> 	CHECK_SIZE("min_t", type, x); \
> 	CHECK_SIZE("min_t", type, y); \
> 	__cmp_once(min, type, x, y); })
> 
> (and similar changes to max_t() and clamp_t().)
> 
> This shows up some real bugs, some unlikely bugs and some false positives.
> In most cases both arguments are unsigned type (just different ones)
> and min_t() can just be replaced by min().
> 
> The patches are all independant and are most of the ones needed to
> get the x86-64 kernel I build to compile.
> I've not tried building an allyesconfig or allmodconfig kernel.
> I've also not included the patch to minmax.h itself.
> 
> I've tried to put the patches that actually fix things first.
> The last one is 0009.
> 
> I gave up on fixing sched/fair.c - it is too broken for a single patch!
> The patch for net/ipv4/tcp.c is also absent because do_tcp_getsockopt()
> needs multiple/larger changes to make it 'sane'.
> 
> I've had to trim the 124 maintainers/lists that get_maintainer.pl finds
> from 124 to under 100 to be able to send the cover letter.
> The individual patches only go to the addresses found for the associated files.
> That reduces the number of emails to a less unsane number.
> 
> David Laight (44):
>   x86/asm/bitops: Change the return type of variable__ffs() to unsigned
>     int
>   ext4: Fix saturation of 64bit inode times for old filesystems
>   perf: Fix branch stack callchain limit
>   io_uring/net: Change some dubious min_t()
>   ipc/msg: Fix saturation of percpu counts in msgctl_info()
>   bpf: Verifier, remove some unusual uses of min_t() and max_t()
>   net/core/flow_dissector: Fix cap of __skb_flow_dissect() return value.
>   net: ethtool: Use min3() instead of nested min_t(u16,...)
>   ipv6: __ip6_append_data() don't abuse max_t() casts
>   x86/crypto: ctr_crypt() use min() instead of min_t()
>   arch/x96/kvm: use min() instead of min_t()
>   block: use min() instead of min_t()
>   drivers/acpi: use min() instead of min_t()
>   drivers/char/hw_random: use min3() instead of nested min_t()
>   drivers/char/tpm: use min() instead of min_t()
>   drivers/crypto/ccp: use min() instead of min_t()
>   drivers/cxl: use min() instead of min_t()
>   drivers/gpio: use min() instead of min_t()
>   drivers/gpu/drm/amd: use min() instead of min_t()
>   drivers/i2c/busses: use min() instead of min_t()
>   drivers/net/ethernet/realtek: use min() instead of min_t()
>   drivers/nvme: use min() instead of min_t()
>   arch/x86/mm: use min() instead of min_t()
>   drivers/nvmem: use min() instead of min_t()
>   drivers/pci: use min() instead of min_t()
>   drivers/scsi: use min() instead of min_t()
>   drivers/tty/vt: use umin() instead of min_t(u16, ...) for row/col
>     limits
>   drivers/usb/storage: use min() instead of min_t()
>   drivers/xen: use min() instead of min_t()
>   fs: use min() or umin() instead of min_t()
>   block: bvec.h: use min() instead of min_t()
>   nodemask: use min() instead of min_t()
>   ipc: use min() instead of min_t()
>   bpf: use min() instead of min_t()
>   bpf_trace: use min() instead of min_t()
>   lib/bucket_locks: use min() instead of min_t()
>   lib/crypto/mpi: use min() instead of min_t()
>   lib/dynamic_queue_limits: use max() instead of max_t()
>   mm: use min() instead of min_t()
>   net: Don't pass bitfields to max_t()
>   net/core: Change loop conditions so min() can be used
>   net: use min() instead of min_t()
>   net/netlink: Use umin() to avoid min_t(int, ...) discarding high bits
>   net/mptcp: Change some dubious min_t(int, ...) to min()
> 
>  arch/x86/crypto/aesni-intel_glue.c            |  3 +-
>  arch/x86/include/asm/bitops.h                 | 18 +++++-------
>  arch/x86/kvm/emulate.c                        |  3 +-
>  arch/x86/kvm/lapic.c                          |  2 +-
>  arch/x86/kvm/mmu/mmu.c                        |  2 +-
>  arch/x86/mm/pat/set_memory.c                  | 12 ++++----
>  block/blk-iocost.c                            |  6 ++--
>  block/blk-settings.c                          |  2 +-
>  block/partitions/efi.c                        |  3 +-
>  drivers/acpi/property.c                       |  2 +-
>  drivers/char/hw_random/core.c                 |  2 +-
>  drivers/char/tpm/tpm1-cmd.c                   |  2 +-
>  drivers/char/tpm/tpm_tis_core.c               |  4 +--
>  drivers/crypto/ccp/ccp-dev.c                  |  2 +-
>  drivers/cxl/core/mbox.c                       |  2 +-
>  drivers/gpio/gpiolib-acpi-core.c              |  2 +-
>  .../gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c  |  4 +--
>  drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c        |  2 +-
>  .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c |  2 +-
>  drivers/i2c/busses/i2c-designware-master.c    |  2 +-
>  drivers/net/ethernet/realtek/r8169_main.c     |  3 +-
>  drivers/nvme/host/pci.c                       |  3 +-
>  drivers/nvme/host/zns.c                       |  3 +-
>  drivers/nvmem/core.c                          |  2 +-
>  drivers/pci/probe.c                           |  3 +-
>  drivers/scsi/hosts.c                          |  2 +-
>  drivers/tty/vt/selection.c                    |  9 +++---
>  drivers/usb/storage/protocol.c                |  3 +-
>  drivers/xen/grant-table.c                     |  2 +-
>  fs/buffer.c                                   |  2 +-
>  fs/exec.c                                     |  2 +-
>  fs/ext4/ext4.h                                |  2 +-
>  fs/ext4/mballoc.c                             |  3 +-
>  fs/ext4/resize.c                              |  2 +-
>  fs/ext4/super.c                               |  2 +-
>  fs/fat/dir.c                                  |  4 +--
>  fs/fat/file.c                                 |  3 +-
>  fs/fuse/dev.c                                 |  2 +-
>  fs/fuse/file.c                                |  8 ++---
>  fs/splice.c                                   |  2 +-
>  include/linux/bvec.h                          |  3 +-
>  include/linux/nodemask.h                      |  9 +++---
>  include/linux/perf_event.h                    |  2 +-
>  include/net/tcp_ecn.h                         |  5 ++--
>  io_uring/net.c                                |  6 ++--
>  ipc/mqueue.c                                  |  4 +--
>  ipc/msg.c                                     |  6 ++--
>  kernel/bpf/core.c                             |  4 +--
>  kernel/bpf/log.c                              |  2 +-
>  kernel/bpf/verifier.c                         | 29 +++++++------------
>  kernel/trace/bpf_trace.c                      |  2 +-
>  lib/bucket_locks.c                            |  2 +-
>  lib/crypto/mpi/mpicoder.c                     |  2 +-
>  lib/dynamic_queue_limits.c                    |  2 +-
>  mm/gup.c                                      |  4 +--
>  mm/memblock.c                                 |  2 +-
>  mm/memory.c                                   |  2 +-
>  mm/percpu.c                                   |  2 +-
>  mm/truncate.c                                 |  3 +-
>  mm/vmscan.c                                   |  2 +-
>  net/core/datagram.c                           |  6 ++--
>  net/core/flow_dissector.c                     |  7 ++---
>  net/core/net-sysfs.c                          |  3 +-
>  net/core/skmsg.c                              |  4 +--
>  net/ethtool/cmis_cdb.c                        |  7 ++---
>  net/ipv4/fib_trie.c                           |  2 +-
>  net/ipv4/tcp_input.c                          |  4 +--
>  net/ipv4/tcp_output.c                         |  5 ++--
>  net/ipv4/tcp_timer.c                          |  4 +--
>  net/ipv6/addrconf.c                           |  8 ++---
>  net/ipv6/ip6_output.c                         |  7 +++--
>  net/ipv6/ndisc.c                              |  5 ++--
>  net/mptcp/protocol.c                          |  8 ++---
>  net/netlink/genetlink.c                       |  9 +++---
>  net/packet/af_packet.c                        |  2 +-
>  net/unix/af_unix.c                            |  4 +--
>  76 files changed, 141 insertions(+), 176 deletions(-)

Patches 10,14,16,37 applied.  Thanks.
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Re: [PATCH 03/44] perf: Fix branch stack callchain limit

[Mi, Dapeng]

On 11/20/2025 6:40 AM, david.laight.linux@gmail.com wrote:
> From: David Laight <david.laight.linux@gmail.com>
>
> The code that bounds the brs->nr to event->attr.sample_max_stack
> incorrectly masks brs->nr with 65535 before the limit check.
> Replace the min_t(u16, ...) with a plain min(...).
>
> I guess there may be another limit on brs->nr (which is u64).
>
> Fixes: c53e14f1ea4a8 ("perf: Extend per event callchain limit to branch stack")
> Signed-off-by: David Laight <david.laight.linux@gmail.com>
> ---
>  include/linux/perf_event.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
> index fd1d91017b99..f91c875ea311 100644
> --- a/include/linux/perf_event.h
> +++ b/include/linux/perf_event.h
> @@ -1430,7 +1430,7 @@ static inline void perf_sample_save_brstack(struct perf_sample_data *data,
>  	if (branch_sample_hw_index(event))
>  		size += sizeof(u64);
>  
> -	brs->nr = min_t(u16, event->attr.sample_max_stack, brs->nr);
> +	brs->nr = min(event->attr.sample_max_stack, brs->nr);
>  
>  	size += brs->nr * sizeof(struct perf_branch_entry);
>  

LGTM. Thanks.

Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com>