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When fetching function arguments out of a frame on amd64, explicitly select

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the register based on the argument index rather than relying on the fields
in struct reg to be in the right order. This assumption is incorrect on
FreeBSD and generally led to bogus argument values for the sixth argument
of PID and USDT probes; the first five are passed directly to dtrace_probe()
via the fasttrap trap handler and so were correctly handled.

MFC after:	2 weeks
This commit is contained in:
Mark Johnston 2013-10-21 04:15:55 +00:00
parent 72c775da6c
commit 7e75d58610
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=256822
2 changed files with 35 additions and 2 deletions
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15
sys/cddl/contrib/opensolaris/uts/intel/dtrace/fasttrap_isa.c
View File

@ -272,7 +272,20 @@ fasttrap_anarg(struct reg *rp, int function_entry, int argno)
* registers.
*/
if (argno < 6)
return ((&rp->r_rdi)[argno]);
switch (argno) {
case 0:
return (rp->r_rdi);
case 1:
return (rp->r_rsi);
case 2:
return (rp->r_rdx);
case 3:
return (rp->r_rcx);
case 4:
return (rp->r_r8);
case 5:
return (rp->r_r9);
}
stack = (uintptr_t *)rp->r_rsp;
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);

22
sys/cddl/dev/dtrace/amd64/dtrace_isa.c
View File

@ -367,7 +367,27 @@ dtrace_getarg(int arg, int aframes)
sizeof (uintptr_t));
if (arg <= inreg) {
stack = (uintptr_t *)&rp->r_rdi;
switch (arg) {
case 0:
stack = (uintptr_t *)&rp->r_rdi;
break;
case 1:
stack = (uintptr_t *)&rp->r_rsi;
break;
case 2:
stack = (uintptr_t *)&rp->r_rdx;
break;
case 3:
stack = (uintptr_t *)&rp->r_rcx;
break;
case 4:
stack = (uintptr_t *)&rp->r_r8;
break;
case 5:
stack = (uintptr_t *)&rp->r_r9;
break;
}
arg = 0;
} else {
stack = (uintptr_t *)(rp->r_rsp);
arg -= inreg;