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authorClément Léger <cleger@rivosinc.com>2023-12-06 14:44:37 +0100
committerPalmer Dabbelt <palmer@rivosinc.com>2024-04-25 18:46:41 +0200
commit17c67ed752d6a456602b3dbb25c5ae4d3de5deab (patch)
treec97d5e9bb66be1b46e3e486209968f2e2657e6d5 /tools
parentriscv: hwprobe: fix invalid sign extension for RISCV_HWPROBE_EXT_ZVFHMIN (diff)
downloadlinux-17c67ed752d6a456602b3dbb25c5ae4d3de5deab.tar.xz
linux-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.c14
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)