Differences From
Artifact [9bf0ba9bf3]:
- File
mod/kcore/syscall.fn.x86.lin.64.s
— part of check-in
[e50a476efe]
at
2019-08-22 02:52:20
on branch trunk
— removed sneaky segfault in x86-64 syscall fn where %r8 (the register that contains the pointer to the syscall arguments from the C syscall wrapper, which need to be copied into the correct registers before the kernel is invoked) gets overwritten if the syscall valency > 5, because of overlapping ccall and syscall ABI argument registers - r8 is clobbered by argument 5 and any further attempts to use it as a ptr segfault at best. also modified the report function so that it immediate cancels compilation if a sub-process reports failure. changed allocator function signatures so they can return a condition code if the kernel reports an error; updated example code so it compiles and runs without fault.
(user:
lexi,
size: 2358)
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[check-ins using]
7 7 ; altogether and access the error value of a
8 8 ; syscall directly. invoke as:
9 9 ;
10 10 ; void k_platform_syscall_raw(s64* result, u64* errno,
11 11 ; syscall, u8 valency, s64[] args)
12 12
13 13 bits 64
14 -%include "arch/posix/x86.lin.64.s"
15 -%include "arch/x86.cdecl.64.s"
14 +
15 +; which file is included is selected via the value
16 +; of the target tuple - arch/$target is passed to
17 +; the assembler as an include directory
18 +%include 'syscall.s'
19 +%include 'cdecl.s'
16 20 ; vim: ft=nasm
17 21
18 22 %macro handle_arg 1
19 23 %assign v %1+1
20 24 mov sys.reg. %+ v, [r15 + 8 * %1]
21 25 dec ccall.reg.3
22 26 jz .perform_call