[PATCH v3 08/11] powerpc/tracing: fix compat syscall handling

Adapt the code to make use of new syscall handling interface

Signed-off-by: Marcin Nowakowski <redacted>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <redacted>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
---
 arch/powerpc/include/asm/ftrace.h | 11 +++++++++++
 arch/powerpc/kernel/ftrace.c      |  4 ++++
 2 files changed, 15 insertions(+)

diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/asm/ftrace.h
index 9697a73..d2ea3b6 100644
--- a/arch/powerpc/include/asm/ftrace.h
+++ b/arch/powerpc/include/asm/ftrace.h

@@ -86,6 +86,17 @@ static inline bool arch_syscall_match_sym_name(const char *sym, const char *name
 	return !strcmp(sym + prefix_len + 1, name + prefix_len);
 }
 #endif
+
+#if defined(CONFIG_COMPAT)
+#include <linux/compat.h>
+#include <asm/compat.h>
+
+#define ARCH_COMPAT_SYSCALL_NUMBERS_OVERLAP 1
+static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
+{
+	return in_compat_syscall();
+}
+#endif /* CONFIG_COMPAT */
 #endif /* CONFIG_FTRACE_SYSCALLS && !__ASSEMBLY__ */
 
 #endif /* _ASM_POWERPC_FTRACE */

diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c
index 5bfb35f..12c00f7 100644
--- a/arch/powerpc/kernel/ftrace.c
+++ b/arch/powerpc/kernel/ftrace.c

@@ -606,6 +606,10 @@ unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip)
 #if defined(CONFIG_FTRACE_SYSCALLS) && defined(CONFIG_PPC64)
 unsigned long __init arch_syscall_addr(int nr, bool compat)
 {
+#ifdef CONFIG_COMPAT
+	if (compat)
+		return sys_call_table[nr*2+1];
+#endif
 	return sys_call_table[nr*2];
 }
 #endif /* CONFIG_FTRACE_SYSCALLS && CONFIG_PPC64 */

-- 
2.7.4

Marcin Nowakowski [off-list ref] writes:

Adapt the code to make use of new syscall handling interface

Signed-off-by: Marcin Nowakowski <redacted>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <redacted>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
---
 arch/powerpc/include/asm/ftrace.h | 11 +++++++++++
 arch/powerpc/kernel/ftrace.c      |  4 ++++

I went to test this and noticed the exit and enter events appear to be
reversed in time? (your series on top of 24532f768121)

  ls-4221  [003] ....    83.766113: compat_sys_rt_sigprocmask -> 0x2
  ls-4221  [003] ....    83.766137: compat_sys_rt_sigprocmask(how: 2, nset: 1010db30, oset: 0, sigsetsize: 8)
  ls-4221  [003] ....    83.766175: compat_sys_rt_sigaction -> 0x14
  ls-4221  [003] ....    83.766175: compat_sys_rt_sigaction(sig: 14, act: ffbd33c4, oact: ffbd3338, sigsetsize: 8)
  ls-4221  [003] ....    83.766177: compat_sys_rt_sigaction -> 0x15
  ls-4221  [003] ....    83.766177: compat_sys_rt_sigaction(sig: 15, act: ffbd33c4, oact: ffbd3338, sigsetsize: 8)
  ls-4221  [003] ....    83.766178: compat_sys_rt_sigaction -> 0x16
  ls-4221  [003] ....    83.766178: compat_sys_rt_sigaction(sig: 16, act: ffbd33d4, oact: ffbd3348, sigsetsize: 8)
  ls-4221  [003] ....    83.766179: sys_setpgid -> 0x107d
  ls-4221  [003] ....    83.766179: sys_setpgid(pid: 107d, pgid: 107d)
  ls-4221  [003] ....    83.766180: compat_sys_rt_sigprocmask -> 0x0
  ls-4221  [003] ....    83.766181: compat_sys_rt_sigprocmask(how: 0, nset: ffbd34b0, oset: ffbd3530, sigsetsize: 8)
  ls-4221  [003] ....    83.766186: compat_sys_ioctl -> 0xff
  ls-4221  [003] ....    83.766187: compat_sys_ioctl(fd: ff, cmd: 80047476, arg32: ffbd3488)
  ls-4221  [003] ....    83.766188: compat_sys_rt_sigprocmask -> 0x2
  ls-4221  [003] ....    83.766189: compat_sys_rt_sigprocmask(how: 2, nset: ffbd3530, oset: 0, sigsetsize: 8)
  ls-4221  [003] ....    83.766189: sys_close -> 0x4
  ls-4221  [003] ....    83.766190: sys_close(fd: 4)
  ls-4221  [003] ....    83.766191: sys_read -> 0x3
  ls-4221  [003] ....    83.766191: sys_read(fd: 3, buf: ffbd35dc, count: 1)
  ls-4221  [003] ....    83.766235: sys_close -> 0x3
  ls-4221  [003] ....    83.766235: sys_close(fd: 3)

cheers

On 12.10.2016 11:59, Michael Ellerman wrote:

I went to test this and noticed the exit and enter events appear to be
reversed in time? (your series on top of 24532f768121)

thanks for testing the patch - I've found a bug that has sneaked in 
while cleaning up the patches before submission ... I'll fix it in the 
next iteration.

Marcin