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| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2010-02-25 20:41:34 (GMT) |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2010-02-25 20:41:34 (GMT) |
| commit | 2a2d10f386c1bacabe1a530c06dc8488eac419e5 (patch) | |
| tree | 4606a4a3bafa42a8aa70e001d35883956a0f0589 /arch/sh/kernel/dwarf.c | |
| parent | 2f68ffd11aa76b251921976c982b814df9ebe890 (diff) | |
| parent | c499546f43f2c31b681271ef7db922839fcde5fe (diff) | |
| download | linux-2a2d10f386c1bacabe1a530c06dc8488eac419e5.tar.xz | |
Merge branch 'for-rmk' of git://git.marvell.com/orion into devel-stable
Diffstat (limited to 'arch/sh/kernel/dwarf.c')
| -rw-r--r-- | arch/sh/kernel/dwarf.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/arch/sh/kernel/dwarf.c b/arch/sh/kernel/dwarf.c index 88d28ec..e511680 100644 --- a/arch/sh/kernel/dwarf.c +++ b/arch/sh/kernel/dwarf.c @@ -540,6 +540,8 @@ void dwarf_free_frame(struct dwarf_frame *frame) mempool_free(frame, dwarf_frame_pool); } +extern void ret_from_irq(void); + /** * dwarf_unwind_stack - unwind the stack * @@ -678,6 +680,24 @@ struct dwarf_frame * dwarf_unwind_stack(unsigned long pc, addr = frame->cfa + reg->addr; frame->return_addr = __raw_readl(addr); + /* + * Ah, the joys of unwinding through interrupts. + * + * Interrupts are tricky - the DWARF info needs to be _really_ + * accurate and unfortunately I'm seeing a lot of bogus DWARF + * info. For example, I've seen interrupts occur in epilogues + * just after the frame pointer (r14) had been restored. The + * problem was that the DWARF info claimed that the CFA could be + * reached by using the value of the frame pointer before it was + * restored. + * + * So until the compiler can be trusted to produce reliable + * DWARF info when it really matters, let's stop unwinding once + * we've calculated the function that was interrupted. + */ + if (prev && prev->pc == (unsigned long)ret_from_irq) + frame->return_addr = 0; + return frame; bail: |