From: Warner Losh <i...@bsdimp.com> FreeBSD system calls return positive errno. On the 4 hosts for which we have support, error is indicated by the C bit set or clear.
Signed-off-by: Warner Losh <i...@bsdimp.com> [rth: Rebase on new safe_syscall_base api; add #error check.] Signed-off-by: Richard Henderson <richard.hender...@linaro.org> --- common-user/host/aarch64/safe-syscall.inc.S | 12 +++++++++++- common-user/host/arm/safe-syscall.inc.S | 11 +++++++++++ common-user/host/i386/safe-syscall.inc.S | 10 ++++++++++ common-user/host/x86_64/safe-syscall.inc.S | 10 ++++++++++ 4 files changed, 42 insertions(+), 1 deletion(-) diff --git a/common-user/host/aarch64/safe-syscall.inc.S b/common-user/host/aarch64/safe-syscall.inc.S index 95c60d8609..d3f065cdef 100644 --- a/common-user/host/aarch64/safe-syscall.inc.S +++ b/common-user/host/aarch64/safe-syscall.inc.S @@ -65,12 +65,22 @@ safe_syscall_start: safe_syscall_end: /* code path for having successfully executed the syscall */ - cmn x0, #4095 +#if defined(__linux__) + /* Linux kernel returns (small) negative errno. */ + cmn x0, #4096 + b.hi 0f +#elif defined(__FreeBSD__) + /* FreeBSD kernel returns positive errno and C bit set. */ b.cs 1f +#else +#error "unsupported os" +#endif ret /* code path setting errno */ +#ifdef __linux__ 0: neg w0, w0 /* create positive errno */ +#endif 1: str w0, [x11] /* store errno */ mov x0, #-1 ret diff --git a/common-user/host/arm/safe-syscall.inc.S b/common-user/host/arm/safe-syscall.inc.S index 17839c6486..328299021d 100644 --- a/common-user/host/arm/safe-syscall.inc.S +++ b/common-user/host/arm/safe-syscall.inc.S @@ -82,12 +82,23 @@ safe_syscall_start: safe_syscall_end: /* code path for having successfully executed the syscall */ +#if defined(__linux__) + /* Linux kernel returns (small) negative errno. */ cmp r0, #-4096 bhi 0f +#elif defined(__FreeBSD__) + /* FreeBSD kernel returns positive errno and C bit set. */ + bcs 1f +#else +#error "unsupported os" +#endif + 9: pop { r4, r5, r6, r7, r8, r9, r10, pc } /* code path setting errno */ +#ifdef __linux__ 0: neg r0, r0 /* create positive errno */ +#endif 1: str r0, [r9] /* store errno */ mov r0, #-1 b 9b diff --git a/common-user/host/i386/safe-syscall.inc.S b/common-user/host/i386/safe-syscall.inc.S index ad89521783..a9382f777e 100644 --- a/common-user/host/i386/safe-syscall.inc.S +++ b/common-user/host/i386/safe-syscall.inc.S @@ -76,8 +76,16 @@ safe_syscall_start: safe_syscall_end: /* code path for having successfully executed the syscall */ +#if defined(__linux__) + /* Linux kernel returns (small) negative errno. */ cmp $-4095, %eax jae 0f +#elif defined(__FreeBSD__) + /* FreeBSD kernel returns positive errno and C bit set. */ + jcs 1f +#else +#error "unsupported os" +#endif 9: pop %ebx .cfi_remember_state @@ -97,7 +105,9 @@ safe_syscall_end: .cfi_restore_state /* code path setting errno */ +#ifdef __linux__ 0: neg %eax /* create positive errno */ +#endif 1: mov 8+16(%esp), %ebx /* load errno pointer */ mov %eax, (%ebx) /* store errno */ mov $-1, %eax diff --git a/common-user/host/x86_64/safe-syscall.inc.S b/common-user/host/x86_64/safe-syscall.inc.S index 9a0c4c93b4..36b7efe2ca 100644 --- a/common-user/host/x86_64/safe-syscall.inc.S +++ b/common-user/host/x86_64/safe-syscall.inc.S @@ -75,8 +75,16 @@ safe_syscall_start: safe_syscall_end: /* code path for having successfully executed the syscall */ +#if defined(__linux__) + /* Linux kernel returns (small) negative errno. */ cmp $-4095, %rax jae 0f +#elif defined(__FreeBSD__) + /* FreeBSD kernel returns positive errno and C bit set. */ + jcs 1f +#else +#error "unsupported os" +#endif 9: pop %rbp .cfi_remember_state @@ -86,7 +94,9 @@ safe_syscall_end: .cfi_restore_state /* code path setting errno */ +#ifdef __linux__ 0: neg %eax /* create positive errno */ +#endif 1: mov %eax, (%rbp) /* store errno */ mov $-1, %rax jmp 9b -- 2.25.1