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authorRoland McGrath <roland@redhat.com>2008-07-09 02:38:07 -0700
committerRoland McGrath <roland@redhat.com>2008-07-16 12:15:17 -0700
commitd4d67150165df8bf1cc05e532f6efca96f907cab (patch)
tree390d5951231c2a1d97d6453d70c42da7af49eeae /arch/x86/kernel/entry_64.S
parent64f097331928b01d704047c1dbc738bb6d2a9bf9 (diff)
downloadop-kernel-dev-d4d67150165df8bf1cc05e532f6efca96f907cab.zip
op-kernel-dev-d4d67150165df8bf1cc05e532f6efca96f907cab.tar.gz
x86 ptrace: unify syscall tracing
This unifies and cleans up the syscall tracing code on i386 and x86_64. Using a single function for entry and exit tracing on 32-bit made the do_syscall_trace() into some terrible spaghetti. The logic is clear and simple using separate syscall_trace_enter() and syscall_trace_leave() functions as on 64-bit. The unification adds PTRACE_SYSEMU and PTRACE_SYSEMU_SINGLESTEP support on x86_64, for 32-bit ptrace() callers and for 64-bit ptrace() callers tracing either 32-bit or 64-bit tasks. It behaves just like 32-bit. Changing syscall_trace_enter() to return the syscall number shortens all the assembly paths, while adding the SYSEMU feature in a simple way. Signed-off-by: Roland McGrath <roland@redhat.com>
Diffstat (limited to 'arch/x86/kernel/entry_64.S')
-rw-r--r--arch/x86/kernel/entry_64.S14
1 files changed, 9 insertions, 5 deletions
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index ae63e58..63001c6 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -349,8 +349,7 @@ ENTRY(system_call_after_swapgs)
movq %rcx,RIP-ARGOFFSET(%rsp)
CFI_REL_OFFSET rip,RIP-ARGOFFSET
GET_THREAD_INFO(%rcx)
- testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP), \
- TI_flags(%rcx)
+ testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%rcx)
jnz tracesys
cmpq $__NR_syscall_max,%rax
ja badsys
@@ -430,7 +429,12 @@ tracesys:
FIXUP_TOP_OF_STACK %rdi
movq %rsp,%rdi
call syscall_trace_enter
- LOAD_ARGS ARGOFFSET /* reload args from stack in case ptrace changed it */
+ /*
+ * Reload arg registers from stack in case ptrace changed them.
+ * We don't reload %rax because syscall_trace_enter() returned
+ * the value it wants us to use in the table lookup.
+ */
+ LOAD_ARGS ARGOFFSET, 1
RESTORE_REST
cmpq $__NR_syscall_max,%rax
ja int_ret_from_sys_call /* RAX(%rsp) set to -ENOSYS above */
@@ -483,7 +487,7 @@ int_very_careful:
ENABLE_INTERRUPTS(CLBR_NONE)
SAVE_REST
/* Check for syscall exit trace */
- testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP),%edx
+ testl $_TIF_WORK_SYSCALL_EXIT,%edx
jz int_signal
pushq %rdi
CFI_ADJUST_CFA_OFFSET 8
@@ -491,7 +495,7 @@ int_very_careful:
call syscall_trace_leave
popq %rdi
CFI_ADJUST_CFA_OFFSET -8
- andl $~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP),%edi
+ andl $~(_TIF_WORK_SYSCALL_EXIT|_TIF_SYSCALL_EMU),%edi
jmp int_restore_rest
int_signal:
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