[PR] {19486} arch/arm: set PSPLIM to top of TLS region to protect it from overflow [nuttx]

["jerpelea (via GitHub)" <gi...@apache.org>]

jerpelea opened a new pull request, #19634:
URL: https://github.com/apache/nuttx/pull/19634

   ## Summary
   
   A crash was observed when running ps: a BusFault in nxtask_argvstr dereferencing tl_argv, because a thread's stack overflow had silently corrupted the TLS region where tl_argv resides.
   
   On ARMv8-M with CONFIG_ARMV8M_STACKCHECK_HARDWARE, PSPLIM was set to stack_alloc_ptr -- the bottom of the allocation where TLS begins. The stack grows downward and TLS occupies [stack_alloc_ptr, stack_alloc_ptr
   + tls_info_size()), so an overflow crossed into TLS and clobbered tl_argv before SP reached the limit, going undetected until code that read the corrupted TLS data (such as ps) hit the bad pointer.
   
   Set the limit to stack_alloc_ptr + tls_info_size() -- the top of the TLS region and the usable stack base -- so an overflow faults at the TLS boundary, before any TLS byte is touched. Include <tls/tls.h> for the tls_info_size() macro, which is the value sched reserves for the TLS region via up_stack_frame().
   
   ## Impact
   
   RELEASE
   
   ## Testing
   
   CI


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Re: [PR] {19486} arch/arm: set PSPLIM to top of TLS region to protect it from overflow [nuttx]

["xiaoxiang781216 (via GitHub)" <gi...@apache.org>]

xiaoxiang781216 merged PR #19634:
URL: https://github.com/apache/nuttx/pull/19634


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