linux.git/lib/bootconfig.c, branch v7.1-rc2

Merge tag 'memblock-v7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock

2026-04-18T18:29:14+00:00

Pull memblock updates from Mike Rapoport:

 - improve debuggability of reserve_mem kernel parameter handling with
   print outs in case of a failure and debugfs info showing what was
   actually reserved

 - Make memblock_free_late() and free_reserved_area() use the same core
   logic for freeing the memory to buddy and ensure it takes care of
   updating memblock arrays when ARCH_KEEP_MEMBLOCK is enabled.

* tag 'memblock-v7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
  x86/alternative: delay freeing of smp_locks section
  memblock: warn when freeing reserved memory before memory map is initialized
  memblock, treewide: make memblock_free() handle late freeing
  memblock: make free_reserved_area() update memblock if ARCH_KEEP_MEMBLOCK=y
  memblock: extract page freeing from free_reserved_area() into a helper
  memblock: make free_reserved_area() more robust
  mm: move free_reserved_area() to mm/memblock.c
  powerpc: opal-core: pair alloc_pages_exact() with free_pages_exact()
  powerpc: fadump: pair alloc_pages_exact() with free_pages_exact()
  memblock: reserve_mem: fix end caclulation in reserve_mem_release_by_name()
  memblock: move reserve_bootmem_range() to memblock.c and make it static
  memblock: Add reserve_mem debugfs info
  memblock: Print out errors on reserve_mem parser

memblock, treewide: make memblock_free() handle late freeing

2026-04-01T08:20:15+00:00

It shouldn't be responsibility of memblock users to detect if they free
memory allocated from memblock late and should use memblock_free_late().

Make memblock_free() and memblock_phys_free() take care of late memory
freeing and drop memblock_free_late().

Link: https://patch.msgid.link/20260323074836.3653702-9-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft)

lib/bootconfig: change xbc_node_index() return type to uint16_t

2026-03-18T23:45:11+00:00

  lib/bootconfig.c:136:21: warning: conversion from 'long int' to
  'int' may change value [-Wconversion]
  lib/bootconfig.c:308:33: warning: conversion from 'int' to 'uint16_t'
  may change value [-Wconversion]
  lib/bootconfig.c:467:37: warning: conversion from 'int' to 'uint16_t'
  may change value [-Wconversion]
  lib/bootconfig.c:469:40: warning: conversion from 'int' to 'uint16_t'
  may change value [-Wconversion]
  lib/bootconfig.c:472:54: warning: conversion from 'int' to 'uint16_t'
  may change value [-Wconversion]
  lib/bootconfig.c:476:45: warning: conversion from 'int' to 'uint16_t'
  may change value [-Wconversion]

xbc_node_index() returns the position of a node in the xbc_nodes array,
which has at most XBC_NODE_MAX (8192) entries, well within uint16_t
range.  Every caller stores the result in a uint16_t field (node->parent,
node->child, node->next, or the keys[] array in compose_key_after), so
the int return type causes narrowing warnings at all six call sites.

Change the return type to uint16_t and add an explicit cast on the
pointer subtraction to match the storage width and eliminate the
warnings.

Link: https://lore.kernel.org/all/20260318155919.78168-14-objecting@objecting.org/

Signed-off-by: Josh Law 
Signed-off-by: Masami Hiramatsu (Google)

lib/bootconfig: use size_t for key length tracking in xbc_verify_tree()

2026-03-18T23:44:58+00:00

  lib/bootconfig.c:839:24: warning: conversion from 'size_t' to 'int'
  may change value [-Wconversion]
  lib/bootconfig.c:860:32: warning: conversion from 'size_t' to 'int'
  may change value [-Wconversion]
  lib/bootconfig.c:860:29: warning: conversion to 'size_t' from 'int'
  may change the sign of the result [-Wsign-conversion]

The key length variables len and wlen accumulate strlen() results but
were declared as int, causing truncation and sign-conversion warnings.
Change both to size_t to match the strlen() return type and avoid
mixed-sign arithmetic.

Link: https://lore.kernel.org/all/20260318155919.78168-13-objecting@objecting.org/

Signed-off-by: Josh Law 
Signed-off-by: Masami Hiramatsu (Google)

lib/bootconfig: use signed type for offset in xbc_init_node()

2026-03-18T23:44:46+00:00

  lib/bootconfig.c:415:32: warning: conversion to 'long unsigned int'
  from 'long int' may change the sign of the result [-Wsign-conversion]

Pointer subtraction yields ptrdiff_t (signed), which was stored in
unsigned long.  The original unsigned type implicitly caught a negative
offset (data < xbc_data) because the wrapped value would exceed
XBC_DATA_MAX.  Make this intent explicit by using a signed long and
adding an offset < 0 check to the WARN_ON condition.

Link: https://lore.kernel.org/all/20260318155919.78168-12-objecting@objecting.org/

Signed-off-by: Josh Law 
Signed-off-by: Masami Hiramatsu (Google)

lib/bootconfig: use size_t for strlen result in xbc_node_match_prefix()

2026-03-18T23:44:34+00:00

  lib/bootconfig.c:198:19: warning: conversion from 'size_t' to 'int'
  may change value [-Wconversion]
  lib/bootconfig.c:200:33: warning: conversion to '__kernel_size_t'
  from 'int' may change the sign of the result [-Wsign-conversion]

strlen() returns size_t but the result was stored in an int.  The value
is then passed back to strncmp() which expects size_t, causing a second
sign-conversion warning on the round-trip.  Use size_t throughout to
match the API types.

Link: https://lore.kernel.org/all/20260318155919.78168-11-objecting@objecting.org/

Signed-off-by: Josh Law 
Signed-off-by: Masami Hiramatsu (Google)

lib/bootconfig: fix signed comparison in xbc_node_get_data()

2026-03-18T23:44:26+00:00

  lib/bootconfig.c:188:28: warning: comparison of integer expressions
  of different signedness: 'int' and 'size_t' [-Wsign-compare]

The local variable 'offset' is declared as int, but xbc_data_size is
size_t.  Change the type to size_t to match and eliminate the warning.

Link: https://lore.kernel.org/all/20260318155919.78168-10-objecting@objecting.org/

Signed-off-by: Josh Law 
Signed-off-by: Masami Hiramatsu (Google)

lib/bootconfig: validate child node index in xbc_verify_tree()

2026-03-18T23:44:15+00:00

xbc_verify_tree() validates that each node's next index is within
bounds, but does not check the child index.  Add the same bounds
check for the child field.

Without this check, a corrupt bootconfig that passes next-index
validation could still trigger an out-of-bounds memory access via an
invalid child index when xbc_node_get_child() is called during tree
traversal at boot time.

Link: https://lore.kernel.org/all/20260318155919.78168-9-objecting@objecting.org/

Signed-off-by: Josh Law 
Signed-off-by: Masami Hiramatsu (Google)

lib/bootconfig: replace linux/kernel.h with specific includes

2026-03-18T23:44:05+00:00

linux/kernel.h is a legacy catch-all header. Replace it with the
specific headers actually needed: linux/cache.h for SMP_CACHE_BYTES,
linux/compiler.h for unlikely(), and linux/sprintf.h for snprintf().

Link: https://lore.kernel.org/all/20260318155919.78168-8-objecting@objecting.org/

Signed-off-by: Josh Law 
Signed-off-by: Masami Hiramatsu (Google)

lib/bootconfig: drop redundant memset of xbc_nodes

2026-03-18T23:43:43+00:00

memblock_alloc() already returns zeroed memory, so the explicit memset
in xbc_init() is redundant. Switch the userspace xbc_alloc_mem() from
malloc() to calloc() so both paths return zeroed memory, and remove
the separate memset call.

Link: https://lore.kernel.org/all/20260318155919.78168-6-objecting@objecting.org/

Signed-off-by: Josh Law 
Signed-off-by: Masami Hiramatsu (Google)