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54991729fd
gdb can only backtrace/unwind across signal handlers if it recognizes the sa_restorer trampoline. for x86_64, gdb first attempts to determine the symbol name for the function in which the program counter resides and match it against "__restore_rt". if no name can be found (e.g. in the case of a stripped binary), the exact instruction sequence is matched instead. when matching the function name, however, gdb's unwind code wrongly considers the interval [sym,sym+size] rather than [sym,sym+size). thus, if __restore_rt begins immediately after another function, gdb wrongly identifies pc as lying within the previous adjacent function. this patch adds a nop before __restore_rt to preclude that possibility. it also removes the symbol name __restore and replaces it with a macro since the stability of whether gdb identifies the function as __restore_rt or __restore is not clear. for the no-symbols case, the instruction sequence is changed to use %rax rather than %eax to match what gdb expects. based on patch by Szabolcs Nagy, with extended description and corresponding x32 changes added. |
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| aarch64 | ||
| arm | ||
| generic/bits | ||
| i386 | ||
| microblaze | ||
| mips | ||
| mips64 | ||
| mipsn32 | ||
| or1k | ||
| powerpc | ||
| powerpc64 | ||
| s390x | ||
| sh | ||
| x32 | ||
| x86_64 | ||