[PATCH 19/23] Make register values available to SH panic notifiers

From: David VomLehn
Date: Mon Apr 12 2010 - 02:05:48 EST


The save_ptregs() functions compiles cleanly for the pre-SH5 code, but has
not been tested. The SH5 code hasn't been compiled.

Signed-off-by: David VomLehn <dvomlehn@xxxxxxxxx>
---
arch/sh/include/asm/ptrace.h | 298 ++++++++++++++++++++++++++++++++++++++++++
arch/sh/kernel/traps_32.c | 4 +-
2 files changed, 300 insertions(+), 2 deletions(-)

diff --git a/arch/sh/include/asm/ptrace.h b/arch/sh/include/asm/ptrace.h
index 1dc12cb..2a18508 100644
--- a/arch/sh/include/asm/ptrace.h
+++ b/arch/sh/include/asm/ptrace.h
@@ -138,6 +138,304 @@ static inline unsigned long profile_pc(struct pt_regs *regs)

return pc;
}
+
+/* Macros for saving the contents of registers and for the output constraint
+ * for those registers */
+
+#include <linux/ptreg.h>
+#include <linux/compiler.h>
+
+/* Location of the TRAPA exception register */
+#define TRA 0xff000020
+
+#if defined(__SH5__)
+#define PTREG_SAVE(r, name) "mov.l " #r ", %[" #name "]\n"
+#else
+#define PTREG_SAVE(r, name) "mov.l " #r ", %[" #name "]\n"
+#endif
+
+#define STR(x) #x
+#define VAL(x) STR(x)
+
+#define PTREG_SAVE_REG(i) _PTREG_SAVE_IDX(r, r, i)
+#define PTREG_SAVE_TREG(i) _PTREG_SAVE_IDX(t, t, i)
+
+#define PTREG_OUT_REG(rp, i) _PTREG_OUT_IDX(rp, regs, r, i)
+#define PTREG_OUT_TREG(rp, i) _PTREG_OUT_IDX(rp, tregs, t, i)
+
+#define arch_has_save_ptregs 1
+
+/**
+ * save_ptregs - save processor registers for backtracing
+ * @regs: Pointer to &struct pt_regs structure in which to save the
+ * registers
+ *
+ * Returns a constant pointer to @regs.
+ *
+ * This function must be called first in a function. There must be no
+ * auto variables defined that are initialized before calling this function.
+ */
+#if defined(__SH5__)
+static __always_inline
+const struct pt_regs *save_ptregs(struct pt_regs *regs)
+{
+ __asm__ __volatile__ (
+ PTREG_SAVE(sr, sr)
+ PTREG_SAVE(syscall_nr, syscall_nr)
+ PTREG_SAVE_REGS(0)
+ PTREG_SAVE_REGS(1)
+ PTREG_SAVE_REGS(2)
+ PTREG_SAVE_REGS(3)
+ PTREG_SAVE_REGS(4)
+ PTREG_SAVE_REGS(5)
+ PTREG_SAVE_REGS(6)
+ PTREG_SAVE_REGS(7)
+ PTREG_SAVE_REGS(8)
+ PTREG_SAVE_REGS(9)
+ PTREG_SAVE_REGS(10)
+ PTREG_SAVE_REGS(11)
+ PTREG_SAVE_REGS(12)
+ PTREG_SAVE_REGS(13)
+ PTREG_SAVE_REGS(14)
+ PTREG_SAVE_REGS(15)
+ PTREG_SAVE_REGS(16)
+ PTREG_SAVE_REGS(17)
+ PTREG_SAVE_REGS(18)
+ PTREG_SAVE_REGS(19)
+ PTREG_SAVE_REGS(20)
+ PTREG_SAVE_REGS(21)
+ PTREG_SAVE_REGS(22)
+ PTREG_SAVE_REGS(23)
+ PTREG_SAVE_REGS(24)
+ PTREG_SAVE_REGS(25)
+ PTREG_SAVE_REGS(26)
+ PTREG_SAVE_REGS(27)
+ PTREG_SAVE_REGS(28)
+ PTREG_SAVE_REGS(29)
+ PTREG_SAVE_REGS(30)
+ PTREG_SAVE_REGS(31)
+ PTREG_SAVE_REGS(32)
+ PTREG_SAVE_REGS(33)
+ PTREG_SAVE_REGS(34)
+ PTREG_SAVE_REGS(35)
+ PTREG_SAVE_REGS(36)
+ PTREG_SAVE_REGS(37)
+ PTREG_SAVE_REGS(38)
+ PTREG_SAVE_REGS(39)
+ PTREG_SAVE_REGS(40)
+ PTREG_SAVE_REGS(41)
+ PTREG_SAVE_REGS(42)
+ PTREG_SAVE_REGS(43)
+ PTREG_SAVE_REGS(44)
+ PTREG_SAVE_REGS(45)
+ PTREG_SAVE_REGS(46)
+ PTREG_SAVE_REGS(47)
+ PTREG_SAVE_REGS(48)
+ PTREG_SAVE_REGS(49)
+ PTREG_SAVE_REGS(50)
+ PTREG_SAVE_REGS(51)
+ PTREG_SAVE_REGS(52)
+ PTREG_SAVE_REGS(53)
+ PTREG_SAVE_REGS(54)
+ PTREG_SAVE_REGS(55)
+ PTREG_SAVE_REGS(56)
+ PTREG_SAVE_REGS(57)
+ PTREG_SAVE_REGS(58)
+ PTREG_SAVE_REGS(59)
+ PTREG_SAVE_REGS(60)
+ PTREG_SAVE_REGS(61)
+ PTREG_SAVE_REGS(62)
+ PTREG_SAVE_REGS(63)
+ PTREG_SAVE_TREGS(0)
+ PTREG_SAVE_TREGS(1)
+ PTREG_SAVE_TREGS(2)
+ PTREG_SAVE_TREGS(3)
+ PTREG_SAVE_TREGS(4)
+ PTREG_SAVE_TREGS(5)
+ PTREG_SAVE_TREGS(6)
+ PTREG_SAVE_TREGS(7)
+ /*
+ * The current location is the one for which the register
+ * values are correct, even if some had been modified on
+ * function entry. So, the current location is the value to
+ * save as the execution address.
+ */
+ "mova 1f, r0\n"
+ "1:\n"
+ PTREG_SAVE(r0, pc)
+ :
+ PTREG_OUT(regs, pc, pc),
+ PTREG_OUT(regs, sr, sr),
+ PTREG_OUT(regs, syscall_nr, syscall_nr),
+ PTREG_OUT_REGS(regs, 0),
+ PTREG_OUT_REGS(regs, 1),
+ PTREG_OUT_REGS(regs, 2),
+ PTREG_OUT_REGS(regs, 3),
+ PTREG_OUT_REGS(regs, 4),
+ PTREG_OUT_REGS(regs, 5),
+ PTREG_OUT_REGS(regs, 6),
+ PTREG_OUT_REGS(regs, 7),
+ PTREG_OUT_REGS(regs, 8),
+ PTREG_OUT_REGS(regs, 9),
+ PTREG_OUT_REGS(regs, 10),
+ PTREG_OUT_REGS(regs, 11),
+ PTREG_OUT_REGS(regs, 12),
+ PTREG_OUT_REGS(regs, 13),
+ PTREG_OUT_REGS(regs, 14),
+ PTREG_OUT_REGS(regs, 15),
+ PTREG_OUT_REGS(regs, 16),
+ PTREG_OUT_REGS(regs, 17),
+ PTREG_OUT_REGS(regs, 18),
+ PTREG_OUT_REGS(regs, 19),
+ PTREG_OUT_REGS(regs, 20),
+ PTREG_OUT_REGS(regs, 21),
+ PTREG_OUT_REGS(regs, 22),
+ PTREG_OUT_REGS(regs, 23),
+ PTREG_OUT_REGS(regs, 24),
+ PTREG_OUT_REGS(regs, 25),
+ PTREG_OUT_REGS(regs, 26),
+ PTREG_OUT_REGS(regs, 27),
+ PTREG_OUT_REGS(regs, 28),
+ PTREG_OUT_REGS(regs, 29),
+ PTREG_OUT_REGS(regs, 30),
+ PTREG_OUT_REGS(regs, 31),
+ PTREG_OUT_REGS(regs, 32),
+ PTREG_OUT_REGS(regs, 33),
+ PTREG_OUT_REGS(regs, 34),
+ PTREG_OUT_REGS(regs, 35),
+ PTREG_OUT_REGS(regs, 36),
+ PTREG_OUT_REGS(regs, 37),
+ PTREG_OUT_REGS(regs, 38),
+ PTREG_OUT_REGS(regs, 39),
+ PTREG_OUT_REGS(regs, 40),
+ PTREG_OUT_REGS(regs, 41),
+ PTREG_OUT_REGS(regs, 42),
+ PTREG_OUT_REGS(regs, 43),
+ PTREG_OUT_REGS(regs, 44),
+ PTREG_OUT_REGS(regs, 45),
+ PTREG_OUT_REGS(regs, 46),
+ PTREG_OUT_REGS(regs, 47),
+ PTREG_OUT_REGS(regs, 48),
+ PTREG_OUT_REGS(regs, 49),
+ PTREG_OUT_REGS(regs, 50),
+ PTREG_OUT_REGS(regs, 51),
+ PTREG_OUT_REGS(regs, 52),
+ PTREG_OUT_REGS(regs, 53),
+ PTREG_OUT_REGS(regs, 54),
+ PTREG_OUT_REGS(regs, 55),
+ PTREG_OUT_REGS(regs, 56),
+ PTREG_OUT_REGS(regs, 57),
+ PTREG_OUT_REGS(regs, 58),
+ PTREG_OUT_REGS(regs, 59),
+ PTREG_OUT_REGS(regs, 60),
+ PTREG_OUT_REGS(regs, 61),
+ PTREG_OUT_REGS(regs, 62),
+ PTREG_OUT_REGS(regs, 63),
+ PTREG_OUT_TREGS(regs, 0),
+ PTREG_OUT_TREGS(regs, 1),
+ PTREG_OUT_TREGS(regs, 2),
+ PTREG_OUT_TREGS(regs, 3),
+ PTREG_OUT_TREGS(regs, 4),
+ PTREG_OUT_TREGS(regs, 5),
+ PTREG_OUT_TREGS(regs, 6),
+ PTREG_OUT_TREGS(regs, 7)
+ :
+ :
+ "r0"
+ );
+
+ return regs;
+}
+#else
+static __always_inline
+const struct pt_regs *save_ptregs(struct pt_regs *regs)
+{
+ __asm__ __volatile__ (
+ PTREG_SAVE_REG(0)
+ PTREG_SAVE_REG(1)
+ PTREG_SAVE_REG(2)
+ PTREG_SAVE_REG(3)
+ PTREG_SAVE_REG(4)
+ PTREG_SAVE_REG(5)
+ PTREG_SAVE_REG(6)
+ PTREG_SAVE_REG(7)
+ PTREG_SAVE_REG(8)
+ PTREG_SAVE_REG(9)
+ PTREG_SAVE_REG(10)
+ PTREG_SAVE_REG(11)
+ PTREG_SAVE_REG(12)
+ PTREG_SAVE_REG(13)
+ PTREG_SAVE_REG(14)
+ PTREG_SAVE_REG(15)
+
+ "sts pr, r0\n"
+ PTREG_SAVE(r0, pr)
+
+ "stc sr, r0\n"
+ PTREG_SAVE(r0, sr)
+
+ "stc gbr,r0\n"
+ PTREG_SAVE(r0, gbr)
+
+ "sts mach, r0\n"
+ PTREG_SAVE(r0, mach)
+
+ "sts macl, r0\n"
+ PTREG_SAVE(r0, macl)
+
+ "mova 1f, r0\n"
+ "mov.l @r0, r0\n"
+ PTREG_SAVE(r0, tra)
+ "bra 2f\n"
+
+ ".align 4\n"
+ "1:\n"
+ ".long " VAL(TRA) "\n"
+ ".align 4\n"
+ "2:\n"
+
+ /*
+ * The current location is the one for which the register
+ * values are correct, even if some had been modified on
+ * function entry. So, the current location is the value to
+ * save as the execution address.
+ */
+ "mova 1f, r0\n"
+ ".align 4\n"
+ "1:\n"
+ PTREG_SAVE(r0, pc)
+ :
+ PTREG_OUT_REG(regs, 0),
+ PTREG_OUT_REG(regs, 1),
+ PTREG_OUT_REG(regs, 2),
+ PTREG_OUT_REG(regs, 3),
+ PTREG_OUT_REG(regs, 4),
+ PTREG_OUT_REG(regs, 5),
+ PTREG_OUT_REG(regs, 6),
+ PTREG_OUT_REG(regs, 7),
+ PTREG_OUT_REG(regs, 8),
+ PTREG_OUT_REG(regs, 9),
+ PTREG_OUT_REG(regs, 10),
+ PTREG_OUT_REG(regs, 11),
+ PTREG_OUT_REG(regs, 12),
+ PTREG_OUT_REG(regs, 13),
+ PTREG_OUT_REG(regs, 14),
+ PTREG_OUT_REG(regs, 15),
+ PTREG_OUT(regs, pc, pc),
+ PTREG_OUT(regs, pr, pr),
+ PTREG_OUT(regs, sr, sr),
+ PTREG_OUT(regs, gbr, gbr),
+ PTREG_OUT(regs, mach, mach),
+ PTREG_OUT(regs, macl, macl),
+ PTREG_OUT(regs, tra, tra)
+ :
+ :
+ "r0"
+ );
+
+ return regs;
+}
+#endif
#endif /* __KERNEL__ */

#endif /* __ASM_SH_PTRACE_H */
diff --git a/arch/sh/kernel/traps_32.c b/arch/sh/kernel/traps_32.c
index 86639be..791edcf 100644
--- a/arch/sh/kernel/traps_32.c
+++ b/arch/sh/kernel/traps_32.c
@@ -176,10 +176,10 @@ void die(const char * str, struct pt_regs * regs, long err)
crash_kexec(regs);

if (in_interrupt())
- panic("Fatal exception in interrupt");
+ panic_with_regs(regs, "Fatal exception in interrupt");

if (panic_on_oops)
- panic("Fatal exception");
+ panic_with_regs(regs, "Fatal exception");

do_exit(SIGSEGV);
}
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