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authorRoland McGrath <roland@redhat.com>2008-07-09 11:38:07 +0200
committerRoland McGrath <roland@redhat.com>2008-07-16 21:15:17 +0200
commitd4d67150165df8bf1cc05e532f6efca96f907cab (patch)
tree390d5951231c2a1d97d6453d70c42da7af49eeae /arch/x86/ia32
parentx86 ptrace: unify TIF_SINGLESTEP (diff)
downloadlinux-d4d67150165df8bf1cc05e532f6efca96f907cab.tar.xz
linux-d4d67150165df8bf1cc05e532f6efca96f907cab.zip
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/ia32')
-rw-r--r--arch/x86/ia32/ia32entry.S17
1 files changed, 9 insertions, 8 deletions
diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S
index 20371d0635e4..8796d1905255 100644
--- a/arch/x86/ia32/ia32entry.S
+++ b/arch/x86/ia32/ia32entry.S
@@ -37,6 +37,11 @@
movq %rax,R8(%rsp)
.endm
+ /*
+ * Reload arg registers from stack in case ptrace changed them.
+ * We don't reload %eax because syscall_trace_enter() returned
+ * the value it wants us to use in the table lookup.
+ */
.macro LOAD_ARGS32 offset
movl \offset(%rsp),%r11d
movl \offset+8(%rsp),%r10d
@@ -46,7 +51,6 @@
movl \offset+48(%rsp),%edx
movl \offset+56(%rsp),%esi
movl \offset+64(%rsp),%edi
- movl \offset+72(%rsp),%eax
.endm
.macro CFI_STARTPROC32 simple
@@ -137,13 +141,12 @@ ENTRY(ia32_sysenter_target)
.previous
GET_THREAD_INFO(%r10)
orl $TS_COMPAT,TI_status(%r10)
- testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP), \
- TI_flags(%r10)
+ testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%r10)
CFI_REMEMBER_STATE
jnz sysenter_tracesys
-sysenter_do_call:
cmpl $(IA32_NR_syscalls-1),%eax
ja ia32_badsys
+sysenter_do_call:
IA32_ARG_FIXUP 1
call *ia32_sys_call_table(,%rax,8)
movq %rax,RAX-ARGOFFSET(%rsp)
@@ -242,8 +245,7 @@ ENTRY(ia32_cstar_target)
.previous
GET_THREAD_INFO(%r10)
orl $TS_COMPAT,TI_status(%r10)
- testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP), \
- TI_flags(%r10)
+ testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%r10)
CFI_REMEMBER_STATE
jnz cstar_tracesys
cstar_do_call:
@@ -336,8 +338,7 @@ ENTRY(ia32_syscall)
SAVE_ARGS 0,0,1
GET_THREAD_INFO(%r10)
orl $TS_COMPAT,TI_status(%r10)
- testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP), \
- TI_flags(%r10)
+ testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%r10)
jnz ia32_tracesys
ia32_do_syscall:
cmpl $(IA32_NR_syscalls-1),%eax