Skip the 4-byte ENDBR when emitting a direct call/jmp to a local function with ENDBR at function entry.
This has been tested on Linux kernel. gcc/ PR target/102953 * config/i386/i386-features.cc (rest_of_insert_endbr_and_patchable_area): Set SYMBOL_FLAG_FUNCTION_ENDBR when inserting ENDBR. * config/i386/i386.cc (ix86_print_operand): Skip the 4-byte ENDBR when calling the local function with ENDBR at function entry. * config/i386/i386.h (SYMBOL_FLAG_FUNCTION_ENDBR): New. (SYMBOL_FLAG_FUNCTION_ENDBR_P): Likewise. gcc/testsuite/ PR target/102953 * gcc.target/i386/pr102953-1.c: New test. * gcc.target/i386/pr102953-2.c: Likewise. --- gcc/config/i386/i386-features.cc | 2 ++ gcc/config/i386/i386.cc | 11 +++++++- gcc/config/i386/i386.h | 5 ++++ gcc/testsuite/gcc.target/i386/pr102953-1.c | 25 ++++++++++++++++++ gcc/testsuite/gcc.target/i386/pr102953-2.c | 30 ++++++++++++++++++++++ 5 files changed, 72 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/gcc.target/i386/pr102953-1.c create mode 100644 gcc/testsuite/gcc.target/i386/pr102953-2.c diff --git a/gcc/config/i386/i386-features.cc b/gcc/config/i386/i386-features.cc index 6fe41c3c24f..3ca1131ed59 100644 --- a/gcc/config/i386/i386-features.cc +++ b/gcc/config/i386/i386-features.cc @@ -1979,6 +1979,8 @@ rest_of_insert_endbr_and_patchable_area (bool need_endbr, || (TARGET_DLLIMPORT_DECL_ATTRIBUTES && DECL_DLLIMPORT_P (cfun->decl)))) { + rtx symbol = XEXP (DECL_RTL (cfun->decl), 0); + SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_FUNCTION_ENDBR; if (crtl->profile && flag_fentry) { /* Queue ENDBR insertion to x86_function_profiler. diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc index b2bf90576d5..33777f942f2 100644 --- a/gcc/config/i386/i386.cc +++ b/gcc/config/i386/i386.cc @@ -13810,7 +13810,16 @@ ix86_print_operand (FILE *file, rtx x, int code) else if (flag_pic || MACHOPIC_INDIRECT) output_pic_addr_const (file, x, code); else - output_addr_const (file, x); + { + /* Skip ENDBR when emitting a direct call/jmp to a local + function with ENDBR at function entry. */ + if (code == 'P' + && GET_CODE (x) == SYMBOL_REF + && SYMBOL_REF_LOCAL_P (x) + && SYMBOL_FLAG_FUNCTION_ENDBR_P (x)) + x = gen_rtx_PLUS (Pmode, x, GEN_INT (4)); + output_addr_const (file, x); + } } } diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h index f41e0908250..e3e50e1ebbb 100644 --- a/gcc/config/i386/i386.h +++ b/gcc/config/i386/i386.h @@ -2786,6 +2786,11 @@ extern GTY(()) tree ms_va_list_type_node; #define SYMBOL_REF_STUBVAR_P(X) \ ((SYMBOL_REF_FLAGS (X) & SYMBOL_FLAG_STUBVAR) != 0) +/* Flag to mark a function with ENDBR at entry. */ +#define SYMBOL_FLAG_FUNCTION_ENDBR (SYMBOL_FLAG_MACH_DEP << 5) +#define SYMBOL_FLAG_FUNCTION_ENDBR_P(X) \ + ((SYMBOL_REF_FLAGS (X) & SYMBOL_FLAG_FUNCTION_ENDBR) != 0) + extern void debug_ready_dispatch (void); extern void debug_dispatch_window (int); diff --git a/gcc/testsuite/gcc.target/i386/pr102953-1.c b/gcc/testsuite/gcc.target/i386/pr102953-1.c new file mode 100644 index 00000000000..2afad391baf --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr102953-1.c @@ -0,0 +1,25 @@ +/* { dg-do compile { target { ! *-*-darwin* } } } */ +/* { dg-options "-O2 -fno-pic -fplt -fcf-protection" } */ + +extern int func (int); + +extern int i; + +__attribute__ ((noclone, noinline, noipa)) +static int +bar (int x) +{ + if (x == 0) + return x; + return bar (x - 1) + func (x); +} + +void * +foo (void) +{ + i = bar (2); + return bar; +} + +/* { dg-final { scan-assembler-times {call\t_?bar\+4\M} 2 } } */ +/* { dg-final { scan-assembler-times {call\t_?func\M} 1 } } */ diff --git a/gcc/testsuite/gcc.target/i386/pr102953-2.c b/gcc/testsuite/gcc.target/i386/pr102953-2.c new file mode 100644 index 00000000000..5b8d517f4f2 --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr102953-2.c @@ -0,0 +1,30 @@ +/* { dg-do compile { target { ! *-*-darwin* } } } */ +/* { dg-options "-O2 -fno-pic -fplt -fcf-protection" } */ + +static int bar (int x); +extern int func (int); + +int +foo (int i) +{ + return bar (i); +} + +void * +bar_p (void) +{ + return bar; +} + +__attribute__ ((noclone, noinline, noipa)) +static int +bar (int x) +{ + if (x == 0) + return x; + return bar (x - 1) + func (x); +} + +/* { dg-final { scan-assembler-times {call\t_?bar\+4\M} 1 } } */ +/* { dg-final { scan-assembler-times {jmp\t_?bar\+4\M} 1 } } */ +/* { dg-final { scan-assembler-times {call\t_?func\M} 1 } } */ -- 2.35.1