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Message-ID: <20100412060429.GA24780@dvomlehn-lnx2.corp.sa.net>
Date: Sun, 11 Apr 2010 23:04:29 -0700
From: David VomLehn <dvomlehn@...co.com>
To: to@...mlehn-lnx2.corp.sa.net,
"linux_arch"@dvomlehn-lnx2.corp.sa.net,
linux_arch@...mlehn-lnx2.corp.sa.net
Cc: akpm@...ux-foundation.org, linux-kernel@...r.kernel.org,
maint_arch@...mlehn-lnx2.corp.sa.net
Subject: [PATCH 16/23] Make register values available to PowerPC panic
notifiers
The save_ptregs() functions compiles cleanly on 32-bit systems, but has not
been tested. Compilation on 64-bit systems has not been done.
Signed-off-by: David VomLehn <dvomlehn@...co.com>
---
arch/powerpc/include/asm/ptrace.h | 167 +++++++++++++++++++++++++++++++++++++
arch/powerpc/kernel/traps.c | 4 +-
2 files changed, 169 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index cbd759e..5b3dd23 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -225,6 +225,7 @@ extern void user_disable_single_step(struct task_struct *);
#define PT_VR0_32 164 /* each Vector reg occupies 4 slots in 32-bit */
#define PT_VSCR_32 (PT_VR0 + 32*4 + 3)
#define PT_VRSAVE_32 (PT_VR0 + 33*4)
+
#endif
/*
@@ -237,6 +238,172 @@ extern void user_disable_single_step(struct task_struct *);
#endif
#endif /* __powerpc64__ */
+#if !defined(__ASSEMBLY__) && defined(__KERNEL__)
+/* Macros for saving the contents of registers and for the output constraint
+ * for those registers */
+
+#include <linux/ptreg.h>
+
+#ifdef __powerpc64__
+#define PTREG_SAVE(r, name) "std " #r ", %[" #name "]\n"
+#else
+#define PTREG_SAVE(r, name) "stw " #r ", %[" #name "]\n"
+#endif
+
+#define PTREG_SAVE_GPR(i) _PTREG_SAVE_IDX(, gpr, i)
+
+#define PTREG_OUT_GPR(regs, i) _PTREG_OUT_IDX(regs, gpr, gpr, 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.
+ */
+static __always_inline
+const struct pt_regs *save_ptregs(struct pt_regs *regs)
+{
+ __asm__ __volatile__ (
+ PTREG_SAVE_GPR(0)
+ PTREG_SAVE_GPR(1)
+ PTREG_SAVE_GPR(2)
+ PTREG_SAVE_GPR(3)
+ PTREG_SAVE_GPR(4)
+ PTREG_SAVE_GPR(5)
+ PTREG_SAVE_GPR(6)
+ PTREG_SAVE_GPR(7)
+ PTREG_SAVE_GPR(8)
+ PTREG_SAVE_GPR(9)
+ PTREG_SAVE_GPR(10)
+ PTREG_SAVE_GPR(11)
+ PTREG_SAVE_GPR(12)
+ PTREG_SAVE_GPR(13)
+ PTREG_SAVE_GPR(14)
+ PTREG_SAVE_GPR(15)
+ PTREG_SAVE_GPR(16)
+ PTREG_SAVE_GPR(17)
+ PTREG_SAVE_GPR(18)
+ PTREG_SAVE_GPR(19)
+ PTREG_SAVE_GPR(20)
+ PTREG_SAVE_GPR(21)
+ PTREG_SAVE_GPR(22)
+ PTREG_SAVE_GPR(23)
+ PTREG_SAVE_GPR(24)
+ PTREG_SAVE_GPR(25)
+ PTREG_SAVE_GPR(26)
+ PTREG_SAVE_GPR(27)
+ PTREG_SAVE_GPR(28)
+ PTREG_SAVE_GPR(29)
+ :
+ PTREG_OUT_GPR(regs, 0),
+ PTREG_OUT_GPR(regs, 1),
+ PTREG_OUT_GPR(regs, 2),
+ PTREG_OUT_GPR(regs, 3),
+ PTREG_OUT_GPR(regs, 4),
+ PTREG_OUT_GPR(regs, 5),
+ PTREG_OUT_GPR(regs, 6),
+ PTREG_OUT_GPR(regs, 7),
+ PTREG_OUT_GPR(regs, 8),
+ PTREG_OUT_GPR(regs, 9),
+ PTREG_OUT_GPR(regs, 10),
+ PTREG_OUT_GPR(regs, 11),
+ PTREG_OUT_GPR(regs, 12),
+ PTREG_OUT_GPR(regs, 13),
+ PTREG_OUT_GPR(regs, 14),
+ PTREG_OUT_GPR(regs, 15),
+ PTREG_OUT_GPR(regs, 16),
+ PTREG_OUT_GPR(regs, 17),
+ PTREG_OUT_GPR(regs, 18),
+ PTREG_OUT_GPR(regs, 19),
+ PTREG_OUT_GPR(regs, 20),
+ PTREG_OUT_GPR(regs, 21),
+ PTREG_OUT_GPR(regs, 22),
+ PTREG_OUT_GPR(regs, 23),
+ PTREG_OUT_GPR(regs, 24),
+ PTREG_OUT_GPR(regs, 25),
+ PTREG_OUT_GPR(regs, 26),
+ PTREG_OUT_GPR(regs, 27),
+ PTREG_OUT_GPR(regs, 28),
+ PTREG_OUT_GPR(regs, 29)
+ :
+ );
+
+ /*
+ * We have a 30 operand limitation in asm statements, so this is the
+ * continuation. Nothing should be happening betweent the two
+ * statements and they are __volatile__, so the registers *shouldn't*
+ * change values.
+ */
+ __asm__ __volatile__ (
+ PTREG_SAVE_GPR(30)
+ PTREG_SAVE_GPR(31)
+
+ /*
+ * Now get various special registers. These must first
+ * be moved to register 0, so the entry value must
+ * already be saved.
+ */
+ "mfxer 0\n"
+ PTREG_SAVE(0, xer)
+
+ "mfmsr 0\n"
+ PTREG_SAVE(0, msr)
+
+ "mfctr 0\n"
+ PTREG_SAVE(0, ctr)
+
+ "mflr 0\n"
+ PTREG_SAVE(0, link)
+
+ "mfcr 0\n"
+ PTREG_SAVE(0, ccr)
+#ifdef __powerpc64__
+ PTREG_SAVE(softe, softe)
+#endif
+ "mfdar 0\n"
+ PTREG_SAVE(0, dar)
+
+ "mfdsisr 0\n"
+ PTREG_SAVE(0, dsisr)
+ "1:\n"
+#ifdef __powerpc64__
+ "li 0, 1b\n"
+#else
+ "lis 0, 1b@ha\n"
+ "addi 0, 0, 1b@l\n"
+#endif
+ PTREG_SAVE(0, nip)
+ :
+ PTREG_OUT_GPR(regs, 30),
+ PTREG_OUT_GPR(regs, 31),
+ PTREG_OUT(regs, xer, xer),
+ PTREG_OUT(regs, msr, msr),
+ PTREG_OUT(regs, ctr, ctr),
+ PTREG_OUT(regs, link, link),
+ PTREG_OUT(regs, ccr, ccr),
+#ifdef __powerpc64__
+ PTREG_OUT(regs, softe, softe),
+#else
+ PTREG_OUT(regs, mq, mq),
+#endif
+ PTREG_OUT(regs, dar, dar),
+ PTREG_OUT(regs, dsisr, dsisr),
+ PTREG_OUT(regs, nip, nip)
+ :
+ :
+ "r0"
+ );
+
+ return regs;
+}
+#endif
+
/*
* Get/set all the altivec registers vr0..vr31, vscr, vrsave, in one go.
* The transfer totals 34 quadword. Quadwords 0-31 contain the
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index d069ff8..9b56fec 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -163,10 +163,10 @@ int die(const char *str, struct pt_regs *regs, long err)
crash_kexec_secondary(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");
oops_exit();
do_exit(err);
--
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