[PATCH 1/1] Add state argument to change_syscall and fix SPARC
James Hogan
james.hogan at imgtec.com
Thu Nov 29 17:37:37 UTC 2012
Add a state argument to change_syscall() so that SPARC can modify that
instead of read-modify-writing the whole register set. This function is
always called within an arg_setup/arg_finish_change sequence which on
certain architectures like SPARC will also be doing a read-modify-write.
This prevents the second write (from arg_finish_change) from undoing the
effects of the change_syscall() call.
* util.c (change_syscall): Add state arg.
Move below definition of arg_setup_state.
Change SPARC to set state->u_regs[U_REG_G1] rather than
read-modify-writing it with PTRACE_GETREGS and PTRACE_SETREGS.
(setbpt, clearbpt): Pass state arg to change_syscall.
Signed-off-by: James Hogan <james.hogan at imgtec.com>
---
Note, I haven't compiled or tested this on SPARC or SPARC64, only on
x86_64. It looks pretty trivial though.
util.c | 220 +++++++++++++++++++++++++++++++--------------------------------
1 files changed, 108 insertions(+), 112 deletions(-)
diff --git a/util.c b/util.c
index 8254677..a439388 100644
--- a/util.c
+++ b/util.c
@@ -1151,116 +1151,6 @@ printcall(struct tcb *tcp)
# define CLONE_VM 0x00000100
#endif
-static int
-change_syscall(struct tcb *tcp, int new)
-{
-#if defined(I386)
- if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(ORIG_EAX * 4), new) < 0)
- return -1;
- return 0;
-#elif defined(X86_64) || defined(X32)
- if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(ORIG_RAX * 8), new) < 0)
- return -1;
- return 0;
-#elif defined(POWERPC)
- if (ptrace(PTRACE_POKEUSER, tcp->pid,
- (char*)(sizeof(unsigned long)*PT_R0), new) < 0)
- return -1;
- return 0;
-#elif defined(S390) || defined(S390X)
- /* s390 linux after 2.4.7 has a hook in entry.S to allow this */
- if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_GPR2), new) < 0)
- return -1;
- return 0;
-#elif defined(M68K)
- if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(4*PT_ORIG_D0), new) < 0)
- return -1;
- return 0;
-#elif defined(SPARC) || defined(SPARC64)
- struct pt_regs regs;
- if (ptrace(PTRACE_GETREGS, tcp->pid, (char*)®s, 0) < 0)
- return -1;
- regs.u_regs[U_REG_G1] = new;
- if (ptrace(PTRACE_SETREGS, tcp->pid, (char*)®s, 0) < 0)
- return -1;
- return 0;
-#elif defined(MIPS)
- if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(REG_V0), new) < 0)
- return -1;
- return 0;
-#elif defined(ALPHA)
- if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(REG_A3), new) < 0)
- return -1;
- return 0;
-#elif defined(AVR32)
- if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(REG_R8), new) < 0)
- return -1;
- return 0;
-#elif defined(BFIN)
- if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(REG_P0), new) < 0)
- return -1;
- return 0;
-#elif defined(IA64)
- if (ia32) {
- switch (new) {
- case 2:
- break; /* x86 SYS_fork */
- case SYS_clone:
- new = 120;
- break;
- default:
- fprintf(stderr, "%s: unexpected syscall %d\n",
- __FUNCTION__, new);
- return -1;
- }
- if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_R1), new) < 0)
- return -1;
- } else if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_R15), new) < 0)
- return -1;
- return 0;
-#elif defined(HPPA)
- if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_GR20), new) < 0)
- return -1;
- return 0;
-#elif defined(SH)
- if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(4*(REG_REG0+3)), new) < 0)
- return -1;
- return 0;
-#elif defined(SH64)
- /* Top half of reg encodes the no. of args n as 0x1n.
- Assume 0 args as kernel never actually checks... */
- if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(REG_SYSCALL),
- 0x100000 | new) < 0)
- return -1;
- return 0;
-#elif defined(CRISV10) || defined(CRISV32)
- if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(4*PT_R9), new) < 0)
- return -1;
- return 0;
-#elif defined(ARM)
- /* Some kernels support this, some (pre-2.6.16 or so) don't. */
-# ifndef PTRACE_SET_SYSCALL
-# define PTRACE_SET_SYSCALL 23
-# endif
- if (ptrace(PTRACE_SET_SYSCALL, tcp->pid, 0, new & 0xffff) != 0)
- return -1;
- return 0;
-#elif defined(TILE)
- if (ptrace(PTRACE_POKEUSER, tcp->pid,
- (char*)PTREGS_OFFSET_REG(0),
- new) != 0)
- return -1;
- return 0;
-#elif defined(MICROBLAZE)
- if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_GPR(0)), new) < 0)
- return -1;
- return 0;
-#else
-#warning Do not know how to handle change_syscall for this architecture
-#endif /* architecture */
- return -1;
-}
-
#ifdef IA64
typedef unsigned long *arg_setup_state;
@@ -1458,6 +1348,111 @@ set_arg1(struct tcb *tcp, void *cookie, long val)
# define arg1_index 1
#endif
+static int
+change_syscall(struct tcb *tcp, arg_setup_state *state, int new)
+{
+#if defined(I386)
+ if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(ORIG_EAX * 4), new) < 0)
+ return -1;
+ return 0;
+#elif defined(X86_64) || defined(X32)
+ if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(ORIG_RAX * 8), new) < 0)
+ return -1;
+ return 0;
+#elif defined(POWERPC)
+ if (ptrace(PTRACE_POKEUSER, tcp->pid,
+ (char*)(sizeof(unsigned long)*PT_R0), new) < 0)
+ return -1;
+ return 0;
+#elif defined(S390) || defined(S390X)
+ /* s390 linux after 2.4.7 has a hook in entry.S to allow this */
+ if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_GPR2), new) < 0)
+ return -1;
+ return 0;
+#elif defined(M68K)
+ if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(4*PT_ORIG_D0), new) < 0)
+ return -1;
+ return 0;
+#elif defined(SPARC) || defined(SPARC64)
+ state->u_regs[U_REG_G1] = new;
+ return 0;
+#elif defined(MIPS)
+ if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(REG_V0), new) < 0)
+ return -1;
+ return 0;
+#elif defined(ALPHA)
+ if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(REG_A3), new) < 0)
+ return -1;
+ return 0;
+#elif defined(AVR32)
+ if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(REG_R8), new) < 0)
+ return -1;
+ return 0;
+#elif defined(BFIN)
+ if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(REG_P0), new) < 0)
+ return -1;
+ return 0;
+#elif defined(IA64)
+ if (ia32) {
+ switch (new) {
+ case 2:
+ break; /* x86 SYS_fork */
+ case SYS_clone:
+ new = 120;
+ break;
+ default:
+ fprintf(stderr, "%s: unexpected syscall %d\n",
+ __FUNCTION__, new);
+ return -1;
+ }
+ if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_R1), new) < 0)
+ return -1;
+ } else if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_R15), new) < 0)
+ return -1;
+ return 0;
+#elif defined(HPPA)
+ if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_GR20), new) < 0)
+ return -1;
+ return 0;
+#elif defined(SH)
+ if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(4*(REG_REG0+3)), new) < 0)
+ return -1;
+ return 0;
+#elif defined(SH64)
+ /* Top half of reg encodes the no. of args n as 0x1n.
+ Assume 0 args as kernel never actually checks... */
+ if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(REG_SYSCALL),
+ 0x100000 | new) < 0)
+ return -1;
+ return 0;
+#elif defined(CRISV10) || defined(CRISV32)
+ if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(4*PT_R9), new) < 0)
+ return -1;
+ return 0;
+#elif defined(ARM)
+ /* Some kernels support this, some (pre-2.6.16 or so) don't. */
+# ifndef PTRACE_SET_SYSCALL
+# define PTRACE_SET_SYSCALL 23
+# endif
+ if (ptrace(PTRACE_SET_SYSCALL, tcp->pid, 0, new & 0xffff) != 0)
+ return -1;
+ return 0;
+#elif defined(TILE)
+ if (ptrace(PTRACE_POKEUSER, tcp->pid,
+ (char*)PTREGS_OFFSET_REG(0),
+ new) != 0)
+ return -1;
+ return 0;
+#elif defined(MICROBLAZE)
+ if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_GPR(0)), new) < 0)
+ return -1;
+ return 0;
+#else
+#warning Do not know how to handle change_syscall for this architecture
+#endif /* architecture */
+ return -1;
+}
+
int
setbpt(struct tcb *tcp)
{
@@ -1488,7 +1483,8 @@ setbpt(struct tcb *tcp)
if (arg_setup(tcp, &state) < 0
|| get_arg0(tcp, &state, &tcp->inst[0]) < 0
|| get_arg1(tcp, &state, &tcp->inst[1]) < 0
- || change_syscall(tcp, clone_scno[current_personality]) < 0
+ || change_syscall(tcp, &state,
+ clone_scno[current_personality]) < 0
|| set_arg0(tcp, &state, CLONE_PTRACE|SIGCHLD) < 0
|| set_arg1(tcp, &state, 0) < 0
|| arg_finish_change(tcp, &state) < 0)
@@ -1531,7 +1527,7 @@ clearbpt(struct tcb *tcp)
{
arg_setup_state state;
if (arg_setup(tcp, &state) < 0
- || change_syscall(tcp, tcp->scno) < 0
+ || change_syscall(tcp, &state, tcp->scno) < 0
|| restore_arg0(tcp, &state, tcp->inst[0]) < 0
|| restore_arg1(tcp, &state, tcp->inst[1]) < 0
|| arg_finish_change(tcp, &state))
--
1.7.7.6
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