On 26.08.20 15:22, Josh Poimboeuf wrote:
On Wed, Aug 26, 2020 at 01:53:57PM +0200, Alexander Graf wrote:
-.macro idtentry_body cfunc has_error_code:req
+.macro idtentry_body cfunc has_error_code:req preserve_error_code:req
call error_entry
UNWIND_HINT_REGS
@@ -328,7 +328,9 @@ SYM_CODE_END(ret_from_fork)
.if \has_error_code == 1
movq ORIG_RAX(%rsp), %rsi /* get error code into 2nd argument*/
- movq $-1, ORIG_RAX(%rsp) /* no syscall to restart */
+ .if \preserve_error_code == 0
+ movq $-1, ORIG_RAX(%rsp) /* no syscall to restart */
+ .endif
When does this happen (has_error_code=1 && preserve_error_code=0)? I
don't see any users of this macro (or idtentry) with this combination.
It's well hidden in arch/x86/include/asm/idtentry.h:
#define DECLARE_IDTENTRY_ERRORCODE(vector, func) \
idtentry vector asm_##func func has_error_code=1
/* Simple exception entries with error code pushed by hardware */
DECLARE_IDTENTRY_ERRORCODE(X86_TRAP_TS, exc_invalid_tss);
DECLARE_IDTENTRY_ERRORCODE(X86_TRAP_NP, exc_segment_not_present);
DECLARE_IDTENTRY_ERRORCODE(X86_TRAP_SS, exc_stack_segment);
DECLARE_IDTENTRY_ERRORCODE(X86_TRAP_GP, exc_general_protection);
DECLARE_IDTENTRY_ERRORCODE(X86_TRAP_AC, exc_alignment_check);
[...]
DECLARE_IDTENTRY_RAW_ERRORCODE(X86_TRAP_PF, exc_page_fault);
Alex
Amazon Development Center Germany GmbH
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Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss
Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B
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