On Fri, Jan 20, 2023 at 2:55 AM Björn Schäpers <g...@hazardy.de> wrote:
>
> From: Björn Schäpers <bjo...@hazardy.de>
>
> Fixes https://github.com/ianlancetaylor/libbacktrace/issues/53, except
> that libraries loaded after the backtrace_initialize are not handled.
> But as far as I can see that's the same for elf.
Thanks, but I don't want a patch that loops using goto statements.
Please rewrite to avoid that. It may be simpler to call a function.
Also starting with a module count of 1000 seems like a lot. Do
typical Windows programs load that many modules?
Ian
> Tested on x86_64-linux and i686-w64-mingw32.
>
> -- >8 --
>
> * pecoff.c (coff_add): New argument for the module handle of the
> file, to get the base address.
> * pecoff.c (backtrace_initialize): Iterate over loaded libraries
> and call coff_add.
>
> Signed-off-by: Björn Schäpers <bjo...@hazardy.de>
> ---
> libbacktrace/pecoff.c | 76 ++++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 72 insertions(+), 4 deletions(-)
>
> diff --git a/libbacktrace/pecoff.c b/libbacktrace/pecoff.c
> index 296f1357b5f..40395109e51 100644
> --- a/libbacktrace/pecoff.c
> +++ b/libbacktrace/pecoff.c
> @@ -49,6 +49,7 @@ POSSIBILITY OF SUCH DAMAGE. */
> #endif
>
> #include <windows.h>
> +#include <psapi.h>
> #endif
>
> /* Coff file header. */
> @@ -592,7 +593,8 @@ coff_syminfo (struct backtrace_state *state, uintptr_t
> addr,
> static int
> coff_add (struct backtrace_state *state, int descriptor,
> backtrace_error_callback error_callback, void *data,
> - fileline *fileline_fn, int *found_sym, int *found_dwarf)
> + fileline *fileline_fn, int *found_sym, int *found_dwarf,
> + uintptr_t module_handle ATTRIBUTE_UNUSED)
> {
> struct backtrace_view fhdr_view;
> off_t fhdr_off;
> @@ -623,7 +625,6 @@ coff_add (struct backtrace_state *state, int descriptor,
> int is_64;
> uintptr_t image_base;
> uintptr_t base_address = 0;
> - uintptr_t module_handle;
> struct dwarf_sections dwarf_sections;
>
> *found_sym = 0;
> @@ -871,7 +872,6 @@ coff_add (struct backtrace_state *state, int descriptor,
> }
>
> #ifdef HAVE_WINDOWS_H
> - module_handle = (uintptr_t) GetModuleHandleW (NULL);
> base_address = module_handle - image_base;
> #endif
>
> @@ -914,12 +914,80 @@ backtrace_initialize (struct backtrace_state *state,
> int found_sym;
> int found_dwarf;
> fileline coff_fileline_fn;
> + uintptr_t module_handle = 0;
> +
> +#ifdef HAVE_WINDOWS_H
> + DWORD i;
> + DWORD module_count;
> + DWORD bytes_needed_for_modules;
> + HMODULE *modules;
> + char module_name[MAX_PATH];
> + int module_found_sym;
> + fileline module_fileline_fn;
> +
> + module_handle = (uintptr_t) GetModuleHandleW (NULL);
> +#endif
>
> ret = coff_add (state, descriptor, error_callback, data,
> - &coff_fileline_fn, &found_sym, &found_dwarf);
> + &coff_fileline_fn, &found_sym, &found_dwarf, module_handle);
> if (!ret)
> return 0;
>
> +#ifdef HAVE_WINDOWS_H
> + module_count = 1000;
> + alloc_modules:
> + modules = backtrace_alloc (state, module_count * sizeof(HMODULE),
> + error_callback, data);
> + if (modules == NULL)
> + goto skip_modules;
> + if (!EnumProcessModules (GetCurrentProcess (), modules, module_count,
> + &bytes_needed_for_modules))
> + {
> + error_callback(data, "Could not enumerate process modules",
> + (int) GetLastError ());
> + goto free_modules;
> + }
> + if (bytes_needed_for_modules > module_count * sizeof(HMODULE))
> + {
> + backtrace_free (state, modules, module_count * sizeof(HMODULE),
> + error_callback, data);
> + // Add an extra of 2, if some module is loaded in another thread.
> + module_count = bytes_needed_for_modules / sizeof(HMODULE) + 2;
> + modules = NULL;
> + goto alloc_modules;
> + }
> +
> + for (i = 0; i < bytes_needed_for_modules / sizeof(HMODULE); ++i)
> + {
> + if (GetModuleFileNameA (modules[i], module_name, MAX_PATH - 1))
> + {
> + if (strcmp (filename, module_name) == 0)
> + continue;
> +
> + module_handle = (uintptr_t) GetModuleHandleA (module_name);
> + if (module_handle == 0)
> + continue;
> +
> + descriptor = backtrace_open (module_name, error_callback, data,
> NULL);
> + if (descriptor < 0)
> + continue;
> +
> + coff_add (state, descriptor, error_callback, data,
> + &module_fileline_fn, &module_found_sym, &found_dwarf,
> + module_handle);
> + if (module_found_sym)
> + found_sym = 1;
> + }
> + }
> +
> + free_modules:
> + if (modules)
> + backtrace_free(state, modules, module_count * sizeof(HMODULE),
> + error_callback, data);
> + modules = NULL;
> + skip_modules:
> +#endif
> +
> if (!state->threaded)
> {
> if (found_sym)
> --
> 2.38.1
>
