The base firmware and an FDPIC module disagree about what a function
pointer is. Firmware is not built FDPIC, so to it a pointer is a code
address and it branches there. A module passes the address of a two word
descriptor instead, because its code and data are placed independently and
a bare code address would leave the callee unable to find its own data. A
firmware routine that takes a callback therefore branches into the
module's data segment and faults.
So the ten entry points that can be handed a callback by a module resolve
the descriptor before storing or branching to it: qsort, bsearch,
pthread_create, signal, sigaction, task_create and task_create_with_stack,
task_spawn, pthread_once, scandir, and mq_notify and timer_create with
SIGEV_THREAD.
Which one resolves matters as much as that one does. Resolving twice would
take an already resolved code address for a descriptor and read two words
from the instruction stream, so each pointer is resolved exactly once, at
the outermost point that sees it. signal() passes its argument through
untouched because sigaction() and then nxsig_action() will resolve it,
which covers a module calling sigaction() directly as well. qsort() is
split so that the public entry resolves and the recursive implementation
does not. scandir() resolves its filter but not its comparison function,
which it hands to qsort().
Whether a caller is a module at all is asked of the PIC base register,
which up_initial_state() sets only for a task that has a D-Space. A plain
kernel task therefore reads zero and is left alone.
SIGEV_THREAD is the case the register cannot answer, because the callback
runs later on a work queue worker that carries no module's base at all.
The base is captured instead when the notification is registered, in the
module's own context, and installed around the call.
All of it is behind CONFIG_FDPIC, which defaults off. Built for
mps3-an547:picostest both ways; with it off the entry points compile to
what they were.
Assisted-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
Signed-off-by: Marco Casaroli <marco.casaroli@gmail.com>
Most tools used for compliance and SBOM generation use SPDX identifiers
This change brings us a step closer to an easy SBOM generation.
Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
remove the advertising clause
3. All advertising materials mentioning features or use of this software must
display the following acknowledgement: This product includes software
developed by the University of California, Berkeley and its contributors.
permitted by Berkley amendment
https://ipira.berkeley.edu/sites/default/files/amendment_of_4-clause_bsd_software_license.pdf
following example from NETBSD and OPENBSD
eb7c1594f16580fee329
Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
=================================================================
==2920138==ERROR: AddressSanitizer: invalid-pointer-pair: 0x603000000130 0x000000000000
#0 0x5602d3c6a89d in qsort stdlib/lib_qsort.c:180
#1 0x5602d3c28928 in romfs_cachenode romfs/fs_romfsutil.c:503
#2 0x5602d3c2854d in romfs_cachenode romfs/fs_romfsutil.c:486
#3 0x5602d3c2b056 in romfs_fsconfigure romfs/fs_romfsutil.c:777
#4 0x5602d3c24856 in romfs_bind romfs/fs_romfs.c:1111
#5 0x5602d3bf5179 in nx_mount mount/fs_mount.c:427
#6 0x5602d3bf5796 in mount mount/fs_mount.c:539
#7 0x5602d3bc1154 in nsh_romfsetc apps/nshlib/nsh_romfsetc.c:110
#8 0x5602d3b8f38d in nsh_initialize apps/nshlib/nsh_init.c:127
#9 0x5602d3b8f2b7 in nsh_main apps/system/nsh/nsh_main.c:69
#10 0x5602d3b7a3a6 in nxtask_startup sched/task_startup.c:70
#11 0x5602d3b5de89 in nxtask_start task/task_start.c:134
0x603000000130 is located 0 bytes inside of 32-byte region [0x603000000130,0x603000000150)
allocated by thread T0 here:
#0 0x7fcdac74793c in __interceptor_posix_memalign ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:226
#1 0x5602d3c9024e in host_memalign sim/posix/sim_hostmemory.c:180
#2 0x5602d3c907d2 in host_realloc sim/posix/sim_hostmemory.c:222
#3 0x5602d3b8aaff in mm_realloc sim/sim_heap.c:262
#4 0x5602d3b87a6a in realloc umm_heap/umm_realloc.c:91
#5 0x5602d3c280c4 in romfs_cachenode romfs/fs_romfsutil.c:466
#6 0x5602d3c2854d in romfs_cachenode romfs/fs_romfsutil.c:486
#7 0x5602d3c2b056 in romfs_fsconfigure romfs/fs_romfsutil.c:777
#8 0x5602d3c24856 in romfs_bind romfs/fs_romfs.c:1111
#9 0x5602d3bf5179 in nx_mount mount/fs_mount.c:427
#10 0x5602d3bf5796 in mount mount/fs_mount.c:539
#11 0x5602d3bc1154 in nsh_romfsetc apps/nshlib/nsh_romfsetc.c:110
#12 0x5602d3b8f38d in nsh_initialize apps/nshlib/nsh_init.c:127
#13 0x5602d3b8f2b7 in nsh_main apps/system/nsh/nsh_main.c:69
#14 0x5602d3b7a3a6 in nxtask_startup sched/task_startup.c:70
#15 0x5602d3b5de89 in nxtask_start task/task_start.c:134
Address 0x000000000000 is a wild pointer.
SUMMARY: AddressSanitizer: invalid-pointer-pair stdlib/lib_qsort.c:180 in qsort
==2920138==ABORTING
Aborted (core dumped)
Signed-off-by: chao an <anchao@xiaomi.com>
Squashed commit of the following:
libs/libxx: Fix some confusing in naming. If the directory is called libxx, then the library must be libxx.a (unless perhaps LIBCXX is selected).
libs/: Fix paths in moved library directories.
libs: Brute force move of libc, libnx, and libxx to libs. Cannot yet build it in that configuration.
