An UEFI application may change the value of the register that gd lives in. But some of our functions like get_ticks() access this register. So we have to set the gd register to the U-Boot value when entering a trace point and set it back to the application value when exiting the trace point.
Signed-off-by: Heinrich Schuchardt xypron.glpk@gmx.de --- lib/trace.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+)
diff --git a/lib/trace.c b/lib/trace.c index 9956442fef..a13e5bf228 100644 --- a/lib/trace.c +++ b/lib/trace.c @@ -56,6 +56,49 @@ static inline uintptr_t __attribute__((no_instrument_function)) return offset / FUNC_SITE_SIZE; }
+#ifdef CONFIG_EFI_LOADER + +/** + * trace_gd - the value of the gd register + */ +static volatile void *trace_gd; + +/** + * trace_save_gd() - save the value of the gd register + */ +static void __attribute__((no_instrument_function)) trace_save_gd(void) +{ + trace_gd = gd; +} + +/** + * trace_swap_gd() - swap between U-Boot and application gd register value + * + * An UEFI application may change the value of the register that gd lives in. + * But some of our functions like get_ticks() access this register. So we + * have to set the gd register to the U-Boot value when entering a trace + * point and set it back to the application value when exiting the trace point. + */ +static void __attribute__((no_instrument_function)) trace_swap_gd(void) +{ + volatile void *temp_gd = trace_gd; + + trace_gd = gd; + gd = temp_gd; +} + +#else + +static void __attribute__((no_instrument_function)) trace_save_gd(void) +{ +} + +static void __attribute__((no_instrument_function)) trace_swap_gd(void) +{ +} + +#endif + static void __attribute__((no_instrument_function)) add_ftrace(void *func_ptr, void *caller, ulong flags) { @@ -100,6 +143,7 @@ void __attribute__((no_instrument_function)) __cyg_profile_func_enter( if (trace_enabled) { int func;
+ trace_swap_gd(); add_ftrace(func_ptr, caller, FUNCF_ENTRY); func = func_ptr_to_num(func_ptr); if (func < hdr->func_count) { @@ -111,6 +155,7 @@ void __attribute__((no_instrument_function)) __cyg_profile_func_enter( hdr->depth++; if (hdr->depth > hdr->depth_limit) hdr->max_depth = hdr->depth; + trace_swap_gd(); } }
@@ -126,8 +171,10 @@ void __attribute__((no_instrument_function)) __cyg_profile_func_exit( void *func_ptr, void *caller) { if (trace_enabled) { + trace_swap_gd(); add_ftrace(func_ptr, caller, FUNCF_EXIT); hdr->depth--; + trace_swap_gd(); } }
@@ -284,6 +331,8 @@ int __attribute__((no_instrument_function)) trace_init(void *buff, size_t needed; int was_disabled = !trace_enabled;
+ trace_save_gd(); + if (!was_disabled) { #ifdef CONFIG_TRACE_EARLY char *end; -- 2.20.1