From a6a2f2ad67506090e332f440457553c0ec011d68 Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Fri, 9 Oct 2009 23:20:54 +0100 Subject: sh: Teach the DWARF unwinder about modules Pass a module's .eh_frame section to the DWARF unwinder at module load time so that the section's FDEs and CIEs can be registered with the DWARF unwinder. This allows us to unwind the stack through module code when generating backtraces. Signed-off-by: Matt Fleming --- arch/sh/include/asm/dwarf.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'arch/sh/include/asm/dwarf.h') diff --git a/arch/sh/include/asm/dwarf.h b/arch/sh/include/asm/dwarf.h index c367ed3373c5..aacdc746d07c 100644 --- a/arch/sh/include/asm/dwarf.h +++ b/arch/sh/include/asm/dwarf.h @@ -241,6 +241,12 @@ struct dwarf_cie { unsigned long flags; #define DWARF_CIE_Z_AUGMENTATION (1 << 0) + + /* + * 'mod' will be non-NULL if this CIE came from a module's + * .eh_frame section. + */ + struct module *mod; }; /** @@ -255,6 +261,12 @@ struct dwarf_fde { unsigned char *instructions; unsigned char *end; struct list_head link; + + /* + * 'mod' will be non-NULL if this FDE came from a module's + * .eh_frame section. + */ + struct module *mod; }; /** @@ -364,6 +376,9 @@ static inline unsigned int DW_CFA_operand(unsigned long insn) extern struct dwarf_frame *dwarf_unwind_stack(unsigned long, struct dwarf_frame *); +extern int dwarf_parse_section(char *, char *, struct module *); +extern void dwarf_module_unload(struct module *); + #endif /* !__ASSEMBLY__ */ #define CFI_STARTPROC .cfi_startproc -- cgit v1.2.2 From ed4fe7f488008f38d5f423f0bcc736b1779d6ddc Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Sat, 10 Oct 2009 16:03:11 +0100 Subject: sh: Fix memory leak in dwarf_unwind_stack() If we broke out of the while (1) loop because the return address of "frame" was zero, then "frame" needs to be free'd before we return. Signed-off-by: Matt Fleming --- arch/sh/include/asm/dwarf.h | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/sh/include/asm/dwarf.h') diff --git a/arch/sh/include/asm/dwarf.h b/arch/sh/include/asm/dwarf.h index aacdc746d07c..eef87539963d 100644 --- a/arch/sh/include/asm/dwarf.h +++ b/arch/sh/include/asm/dwarf.h @@ -376,6 +376,7 @@ static inline unsigned int DW_CFA_operand(unsigned long insn) extern struct dwarf_frame *dwarf_unwind_stack(unsigned long, struct dwarf_frame *); +extern void dwarf_free_frame(struct dwarf_frame *); extern int dwarf_parse_section(char *, char *, struct module *); extern void dwarf_module_unload(struct module *); -- cgit v1.2.2 From ac4fac8cb24ab209ae373a3e3e9995dff7d0c394 Mon Sep 17 00:00:00 2001 From: Paul Mundt Date: Tue, 13 Oct 2009 13:10:14 +0900 Subject: sh: Generalize CALLER_ADDRx support. This splits out the unwinder implementation and adds a new return_address() abstraction modelled after the ARM code. The DWARF unwinder is tied in to this, returning NULL otherwise in the case of being unable to support arbitrary depths. This enables us to get correct behaviour with the unwinder enabled, as well as disabling the arbitrary depth support when frame pointers are enabled, as arbitrary depths with __builtin_return_address() are not supported regardless. With this abstraction it's also possible to layer on a simplified implementation with frame pointers in the event that the unwinder isn't enabled, although this is left as a future exercise. Signed-off-by: Paul Mundt --- arch/sh/include/asm/dwarf.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'arch/sh/include/asm/dwarf.h') diff --git a/arch/sh/include/asm/dwarf.h b/arch/sh/include/asm/dwarf.h index fc51e66f2380..d985148af19f 100644 --- a/arch/sh/include/asm/dwarf.h +++ b/arch/sh/include/asm/dwarf.h @@ -194,6 +194,11 @@ #define DWARF_ARCH_RA_REG 17 #ifndef __ASSEMBLY__ + +#include +#include +#include + /* * Read either the frame pointer (r14) or the stack pointer (r15). * NOTE: this MUST be inlined. -- cgit v1.2.2 From 5a3abba77dc0eb0b00332c21899123cdfa3b19e5 Mon Sep 17 00:00:00 2001 From: Paul Mundt Date: Tue, 13 Oct 2009 13:32:19 +0900 Subject: sh: Tidy up the dwarf module helpers. This enables us to build the dwarf unwinder both with modules enabled and disabled in addition to reducing code size in the latter case. The helpers are also consolidated, and modified to resemble the BUG module helpers. Signed-off-by: Paul Mundt --- arch/sh/include/asm/dwarf.h | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'arch/sh/include/asm/dwarf.h') diff --git a/arch/sh/include/asm/dwarf.h b/arch/sh/include/asm/dwarf.h index d985148af19f..bdccbbfdc0bd 100644 --- a/arch/sh/include/asm/dwarf.h +++ b/arch/sh/include/asm/dwarf.h @@ -198,6 +198,7 @@ #include #include #include +#include /* * Read either the frame pointer (r14) or the stack pointer (r15). @@ -382,8 +383,10 @@ static inline unsigned int DW_CFA_operand(unsigned long insn) extern struct dwarf_frame *dwarf_unwind_stack(unsigned long, struct dwarf_frame *); extern void dwarf_free_frame(struct dwarf_frame *); -extern int dwarf_parse_section(char *, char *, struct module *); -extern void dwarf_module_unload(struct module *); + +extern int module_dwarf_finalize(const Elf_Ehdr *, const Elf_Shdr *, + struct module *); +extern void module_dwarf_cleanup(struct module *); #endif /* !__ASSEMBLY__ */ @@ -412,6 +415,10 @@ extern void dwarf_module_unload(struct module *); static inline void dwarf_unwinder_init(void) { } + +#define module_dwarf_finalize(hdr, sechdrs, me) (0) +#define module_dwarf_cleanup(mod) do { } while (0) + #endif #endif /* CONFIG_DWARF_UNWINDER */ -- cgit v1.2.2