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| author | Kimplul <kimi.h.kuparinen@gmail.com> | 2023-06-08 18:43:18 +0300 |
|---|---|---|
| committer | Kimplul <kimi.h.kuparinen@gmail.com> | 2023-06-08 18:43:18 +0300 |
| commit | dd10667c56b943c19436c6540946f9ad0f71d257 (patch) | |
| tree | 407bb9cea33344831c17347183303e8de0200b78 | |
| parent | a8540ed5cc382ac71716b9978862e57edf274d77 (diff) | |
| download | kmi-dd10667c56b943c19436c6540946f9ad0f71d257.tar.gz kmi-dd10667c56b943c19436c6540946f9ad0f71d257.zip | |
add fast userspace return to do_ipc
| -rw-r--r-- | arch/riscv64/kernel/entry.S | 21 | ||||
| -rw-r--r-- | common/uapi/ipc.c | 1 | ||||
| -rw-r--r-- | docs/doxygen.conf | 3 | ||||
| -rw-r--r-- | include/arch/proc.h | 10 |
4 files changed, 34 insertions, 1 deletions
diff --git a/arch/riscv64/kernel/entry.S b/arch/riscv64/kernel/entry.S index 32a04f6..2f9a9e6 100644 --- a/arch/riscv64/kernel/entry.S +++ b/arch/riscv64/kernel/entry.S @@ -149,3 +149,24 @@ _load_context: /* assume supervisor for now */ sret + +.global ret_userspace_fast +ret_userspace_fast: + lr sp, offsetof_regs(tp) + addi sp, sp, -sizeof_registers + + lr s0, offsetof_exec(tp) + csrw CSR_SEPC, s0 + + csrw CSR_SSCRATCH, tp + + lr a0, offsetof_a0(sp) + lr a1, offsetof_a1(sp) + lr a2, offsetof_a2(sp) + lr a3, offsetof_a3(sp) + lr a4, offsetof_a4(sp) + lr a5, offsetof_a5(sp) + + lr sp, offsetof_sp(sp) + + sret diff --git a/common/uapi/ipc.c b/common/uapi/ipc.c index 36f2941..1d48f71 100644 --- a/common/uapi/ipc.c +++ b/common/uapi/ipc.c @@ -255,6 +255,7 @@ static void do_ipc(struct tcb *t, t->eid = t->pid; finalize_rpc(t, r, sd); + ret_userspace_fast(); } /** * IPC request syscall handler. diff --git a/docs/doxygen.conf b/docs/doxygen.conf index 71a053c..3cb6ca3 100644 --- a/docs/doxygen.conf +++ b/docs/doxygen.conf @@ -2337,7 +2337,8 @@ INCLUDE_FILE_PATTERNS = PREDEFINED = DEBUG \ __GNUC__ \ riscv64 \ - riscv32 + riscv32 \ + ASSERT # If the MACRO_EXPANSION and EXPAND_ONLY_PREDEF tags are set to YES then this # tag can be used to specify a list of macro names that should be expanded. The diff --git a/include/arch/proc.h b/include/arch/proc.h index 493b168..c9b54db 100644 --- a/include/arch/proc.h +++ b/include/arch/proc.h @@ -113,4 +113,14 @@ void adjust_syscall(struct tcb *t); */ __noreturn void run_init(struct tcb *t, void *fdt); +/** + * Return to userspace fast. + * Doesn't load registers besides arguments. + * Mainly for do_ipc(). + * Note that this skips canary checking, + * but at least do_ipc() uses basically zero stack space + * so I'm not too worried. + */ +__noreturn void ret_userspace_fast(); + #endif /* KMI_ARCH_PROC_H */ |