Re: [PATCH v3 21/21] klp-build: Add arm64 syscall patching macro
| Newsgroups | org.kernel.vger.live-patching,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <[email protected]> |
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider: - [Medium] The arm64 __KLP_SYSCALL_DEFINEx macro omits the ALLOW_ERROR_INJECTION declaration, silently breaking BPF error injection for livepatched syscalls. -- commit b4d1a9ea352f196a7fd3e7198fdade51440d08e5 Author: Josh Poimboeuf <[email protected]> klp-build: Add arm64 syscall patching macro This commit adds arm64 support for KLP_SYSCALL_DEFINEx(). The commit message states it is mirroring the arm64 __SYSCALL_DEFINEx() pattern from arch/arm64/include/asm/syscall_wrapper.h. > diff --git a/include/linux/livepatch_helpers.h b/include/linux/livepatch_helpers.h > index 99d68d0773fa8..4b647b83865f9 100644 > --- a/include/linux/livepatch_helpers.h > +++ b/include/linux/livepatch_helpers.h > @@ -72,6 +72,25 @@ > } \ > static inline long __klp_do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) > > +#elif defined(CONFIG_ARM64) > + > +#define __KLP_SYSCALL_DEFINEx(x, name, ...) \ > + static long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \ > + static inline long __klp_do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));\ > + asmlinkage long __arm64_sys##name(const struct pt_regs *regs); \ > + asmlinkage long __arm64_sys##name(const struct pt_regs *regs) \ > + { \ > + return __se_sys##name(SC_ARM64_REGS_TO_ARGS(x,__VA_ARGS__));\ > + } \ Does this macro definition omit the ALLOW_ERROR_INJECTION declaration? The standard arm64 __SYSCALL_DEFINEx() macro explicitly registers the top-level syscall handler with ALLOW_ERROR_INJECTION() to enable BPF error injection workflows like bpf_override_return(). The x86 implementation correctly preserves this functionality. Because this macro is missing that declaration, it looks like it might introduce a regression where BPF cannot inject errors into the replacement syscalls in a livepatch module on arm64. [ ... ] -- Sashiko AI review · https://sashiko.dev/#/patchset/[email protected]?part=21