linux_dsm_epyc7002/arch/sh/include/asm/ptrace_32.h
Eric Paris d7e7528bcd Audit: push audit success and retcode into arch ptrace.h
The audit system previously expected arches calling to audit_syscall_exit to
supply as arguments if the syscall was a success and what the return code was.
Audit also provides a helper AUDITSC_RESULT which was supposed to simplify things
by converting from negative retcodes to an audit internal magic value stating
success or failure.  This helper was wrong and could indicate that a valid
pointer returned to userspace was a failed syscall.  The fix is to fix the
layering foolishness.  We now pass audit_syscall_exit a struct pt_reg and it
in turns calls back into arch code to collect the return value and to
determine if the syscall was a success or failure.  We also define a generic
is_syscall_success() macro which determines success/failure based on if the
value is < -MAX_ERRNO.  This works for arches like x86 which do not use a
separate mechanism to indicate syscall failure.

We make both the is_syscall_success() and regs_return_value() static inlines
instead of macros.  The reason is because the audit function must take a void*
for the regs.  (uml calls theirs struct uml_pt_regs instead of just struct
pt_regs so audit_syscall_exit can't take a struct pt_regs).  Since the audit
function takes a void* we need to use static inlines to cast it back to the
arch correct structure to dereference it.

The other major change is that on some arches, like ia64, MIPS and ppc, we
change regs_return_value() to give us the negative value on syscall failure.
THE only other user of this macro, kretprobe_example.c, won't notice and it
makes the value signed consistently for the audit functions across all archs.

In arch/sh/kernel/ptrace_64.c I see that we were using regs[9] in the old
audit code as the return value.  But the ptrace_64.h code defined the macro
regs_return_value() as regs[3].  I have no idea which one is correct, but this
patch now uses the regs_return_value() function, so it now uses regs[3].

For powerpc we previously used regs->result but now use the
regs_return_value() function which uses regs->gprs[3].  regs->gprs[3] is
always positive so the regs_return_value(), much like ia64 makes it negative
before calling the audit code when appropriate.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: H. Peter Anvin <hpa@zytor.com> [for x86 portion]
Acked-by: Tony Luck <tony.luck@intel.com> [for ia64]
Acked-by: Richard Weinberger <richard@nod.at> [for uml]
Acked-by: David S. Miller <davem@davemloft.net> [for sparc]
Acked-by: Ralf Baechle <ralf@linux-mips.org> [for mips]
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [for ppc]
2012-01-17 16:16:56 -05:00

87 lines
1.7 KiB
C

#ifndef __ASM_SH_PTRACE_32_H
#define __ASM_SH_PTRACE_32_H
/*
* GCC defines register number like this:
* -----------------------------
* 0 - 15 are integer registers
* 17 - 22 are control/special registers
* 24 - 39 fp registers
* 40 - 47 xd registers
* 48 - fpscr register
* -----------------------------
*
* We follows above, except:
* 16 --- program counter (PC)
* 22 --- syscall #
* 23 --- floating point communication register
*/
#define REG_REG0 0
#define REG_REG15 15
#define REG_PC 16
#define REG_PR 17
#define REG_SR 18
#define REG_GBR 19
#define REG_MACH 20
#define REG_MACL 21
#define REG_SYSCALL 22
#define REG_FPREG0 23
#define REG_FPREG15 38
#define REG_XFREG0 39
#define REG_XFREG15 54
#define REG_FPSCR 55
#define REG_FPUL 56
/*
* This struct defines the way the registers are stored on the
* kernel stack during a system call or other kernel entry.
*/
struct pt_regs {
unsigned long regs[16];
unsigned long pc;
unsigned long pr;
unsigned long sr;
unsigned long gbr;
unsigned long mach;
unsigned long macl;
long tra;
};
/*
* This struct defines the way the DSP registers are stored on the
* kernel stack during a system call or other kernel entry.
*/
struct pt_dspregs {
unsigned long a1;
unsigned long a0g;
unsigned long a1g;
unsigned long m0;
unsigned long m1;
unsigned long a0;
unsigned long x0;
unsigned long x1;
unsigned long y0;
unsigned long y1;
unsigned long dsr;
unsigned long rs;
unsigned long re;
unsigned long mod;
};
#ifdef __KERNEL__
#define MAX_REG_OFFSET offsetof(struct pt_regs, tra)
static inline long regs_return_value(struct pt_regs *regs)
{
return regs->regs[0];
}
#endif /* __KERNEL__ */
#endif /* __ASM_SH_PTRACE_32_H */