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| author |  Peter Zijlstra <peterz@infradead.org>
| 2022-09-15 13:11:33 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org>
| 2022-10-17 16:41:17 +0200 |
| commit | 396e0b8e09e86440c2119d12c2101110d3cd5bf9 (patch) | |
| tree | 1c1177879cb877b61d64b5851acdddb15fef01c2 /arch/x86 | |
| parent | kallsyms: Take callthunks into account (diff) | |
| download | linux-396e0b8e09e86440c2119d12c2101110d3cd5bf9.tar.gz linux-396e0b8e09e86440c2119d12c2101110d3cd5bf9.tar.bz2 linux-396e0b8e09e86440c2119d12c2101110d3cd5bf9.zip | |
x86/orc: Make it callthunk aware
Callthunks addresses on the stack would confuse the ORC unwinder. Handle
them correctly and tell ORC to proceed further down the stack.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220915111148.511637628@infradead.org
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/alternative.h | 5 | ||||
| -rw-r--r-- | arch/x86/kernel/callthunks.c | 13 | ||||
| -rw-r--r-- | arch/x86/kernel/unwind_orc.c | 21 |
3 files changed, 38 insertions, 1 deletions
diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h index 07ac25793a3f..4b8cd256c95e 100644 --- a/arch/x86/include/asm/alternative.h +++ b/arch/x86/include/asm/alternative.h @@ -92,6 +92,7 @@ extern void callthunks_patch_builtin_calls(void); extern void callthunks_patch_module_calls(struct callthunk_sites *sites, struct module *mod); extern void *callthunks_translate_call_dest(void *dest); +extern bool is_callthunk(void *addr); #else static __always_inline void callthunks_patch_builtin_calls(void) {} static __always_inline void @@ -101,6 +102,10 @@ static __always_inline void *callthunks_translate_call_dest(void *dest) { return dest; } +static __always_inline bool is_callthunk(void *addr) +{ + return false; +} #endif #ifdef CONFIG_SMP diff --git a/arch/x86/kernel/callthunks.c b/arch/x86/kernel/callthunks.c index 071003605a86..7f9788194eb5 100644 --- a/arch/x86/kernel/callthunks.c +++ b/arch/x86/kernel/callthunks.c @@ -293,6 +293,19 @@ void *callthunks_translate_call_dest(void *dest) return target ? : dest; } +bool is_callthunk(void *addr) +{ + unsigned int tmpl_size = SKL_TMPL_SIZE; + void *tmpl = skl_call_thunk_template; + unsigned long dest; + + dest = roundup((unsigned long)addr, CONFIG_FUNCTION_ALIGNMENT); + if (!thunks_initialized || skip_addr((void *)dest)) + return false; + + return !bcmp((void *)(dest - tmpl_size), tmpl, tmpl_size); +} + #ifdef CONFIG_MODULES void noinline callthunks_patch_module_calls(struct callthunk_sites *cs, struct module *mod) diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c index 0ea57da92940..cfac2b54b37b 100644 --- a/arch/x86/kernel/unwind_orc.c +++ b/arch/x86/kernel/unwind_orc.c @@ -136,6 +136,21 @@ static struct orc_entry null_orc_entry = { .type = UNWIND_HINT_TYPE_CALL }; +#ifdef CONFIG_CALL_THUNKS +static struct orc_entry *orc_callthunk_find(unsigned long ip) +{ + if (!is_callthunk((void *)ip)) + return NULL; + + return &null_orc_entry; +} +#else +static struct orc_entry *orc_callthunk_find(unsigned long ip) +{ + return NULL; +} +#endif + /* Fake frame pointer entry -- used as a fallback for generated code */ static struct orc_entry orc_fp_entry = { .type = UNWIND_HINT_TYPE_CALL, @@ -189,7 +204,11 @@ static struct orc_entry *orc_find(unsigned long ip) if (orc) return orc; - return orc_ftrace_find(ip); + orc = orc_ftrace_find(ip); + if (orc) + return orc; + + return orc_callthunk_find(ip); } #ifdef CONFIG_MODULES |