Fix concurrency bug and use uintptr_t for ABI

[jserv]

This replaces global in_syscall_context flag with per-task tracking in TCB. Global flag was corrupted when Task A yielded during syscall and Task B ran another syscall, clearing the flag before Task A resumed.

• Add volatile bool in_syscall to tcb_t (survives preemption)
• Update do_syscall to track per-task context
• Update mo_task_spawn_kernel to check per-task flag
• Use uintptr_t for syscall arguments (matches RISC-V ABI semantics)

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Summary by cubic

Fix a race in syscall context tracking by moving from a global flag to per-task tracking, ensuring correct privilege enforcement across preemption. Also switch syscall argument types to uintptr_t to match the RISC-V ABI.

• Bug Fixes

  • Replace global in_syscall_context with tcb_t.in_syscall (volatile, per-task).
  • Set/clear the flag in do_syscall so it survives preemption.
  • Update mo_task_spawn_kernel to use the per-task flag and block calls from syscall context.

• Refactors

  • Use uintptr_t for syscall arguments across entry, HAL, headers, and syscall dispatch.
  • Update user-space wrappers to cast to uintptr_t, aligning with RISC-V register conventions.

^{Written for commit bb6344f. Summary will update on new commits.}

[github-actions]

Linmo CI Test Results

Overall Status: ✅ passed
Timestamp: 2026-01-29T05:16:37+00:00
Commit: e4cbe20

Toolchain Results

Toolchain	Build	Crash Test	Functional
GNU	✅ passed	✅ passed	✅ passed
LLVM	✅ passed	⏭️ skipped	⏭️ skipped

Application Tests

App	GNU	LLVM
cond	✅ passed	⏭️ skipped
coop	✅ passed	⏭️ skipped
cpubench	✅ passed	⏭️ skipped
echo	✅ passed	⏭️ skipped
hello	✅ passed	⏭️ skipped
mqueues	✅ passed	⏭️ skipped
mutex	✅ passed	⏭️ skipped
pipes	✅ passed	⏭️ skipped
pipes_small	✅ passed	⏭️ skipped
pipes_struct	✅ passed	⏭️ skipped
prodcons	✅ passed	⏭️ skipped
progress	✅ passed	⏭️ skipped
rtsched	✅ passed	⏭️ skipped
semaphore	✅ passed	⏭️ skipped
suspend	✅ passed	⏭️ skipped
test64	✅ passed	⏭️ skipped
test_libc	✅ passed	⏭️ skipped
timer	✅ passed	⏭️ skipped
timer_kill	✅ passed	⏭️ skipped
umode	⚠️	⏭️ skipped

Functional Test Details

Test	GNU	LLVM
mutex:data_consistency	✅ passed	⏭️ skipped
mutex:fairness	✅ passed	⏭️ skipped
mutex:mutual_exclusion	✅ passed	⏭️ skipped
mutex:overall	✅ passed	⏭️ skipped
semaphore:overall	✅ passed	⏭️ skipped
umode:[exception]_illegal_instruction	✅ passed	⚠️
umode:pass:_sys_tid()_returned	✅ passed	⚠️
umode:pass:_sys_uptime()_returned	✅ passed	⚠️

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Report generated from test-summary.toml

[cubic-dev-ai]

No issues found across 6 files

[HeatCrab]

LGTM!