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| author | Clément Léger <cleger@rivosinc.com> | 2023-12-06 14:44:37 +0100 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2024-04-25 09:46:41 -0700 |
| commit | 17c67ed752d6a456602b3dbb25c5ae4d3de5deab (patch) | |
| tree | c97d5e9bb66be1b46e3e486209968f2e2657e6d5 /tools | |
| parent | 5ea6764d9095e234b024054f75ebbccc4f0eb146 (diff) | |
| download | lwn-17c67ed752d6a456602b3dbb25c5ae4d3de5deab.tar.gz lwn-17c67ed752d6a456602b3dbb25c5ae4d3de5deab.zip | |
selftests: sud_test: return correct emulated syscall value on RISC-V
Currently, the sud_test expects the emulated syscall to return the
emulated syscall number. This assumption only works on architectures
were the syscall calling convention use the same register for syscall
number/syscall return value. This is not the case for RISC-V and thus
the return value must be also emulated using the provided ucontext.
Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Link: https://lore.kernel.org/r/20231206134438.473166-1-cleger@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/syscall_user_dispatch/sud_test.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/tools/testing/selftests/syscall_user_dispatch/sud_test.c b/tools/testing/selftests/syscall_user_dispatch/sud_test.c index b5d592d4099e..d975a6767329 100644 --- a/tools/testing/selftests/syscall_user_dispatch/sud_test.c +++ b/tools/testing/selftests/syscall_user_dispatch/sud_test.c @@ -158,6 +158,20 @@ static void handle_sigsys(int sig, siginfo_t *info, void *ucontext) /* In preparation for sigreturn. */ SYSCALL_DISPATCH_OFF(glob_sel); + + /* + * The tests for argument handling assume that `syscall(x) == x`. This + * is a NOP on x86 because the syscall number is passed in %rax, which + * happens to also be the function ABI return register. Other + * architectures may need to swizzle the arguments around. + */ +#if defined(__riscv) +/* REG_A7 is not defined in libc headers */ +# define REG_A7 (REG_A0 + 7) + + ((ucontext_t *)ucontext)->uc_mcontext.__gregs[REG_A0] = + ((ucontext_t *)ucontext)->uc_mcontext.__gregs[REG_A7]; +#endif } TEST(dispatch_and_return) |