4.18-stable review patch. If anyone has any objections, please let me know.
------------------ From: Mathieu Desnoyers <[email protected]> commit ce01a1575f45bf319e374592656441021a7f5823 upstream. On x86-64, the parametrized selftest code for rseq crashes with a segmentation fault when compiled with -fpie. This happens when the param_test binary is loaded at an address beyond 32-bit on x86-64. The issue is caused by use of a 32-bit register to hold the address of the loop counter variable. Fix this by using a 64-bit register to calculate the address of the loop counter variables as an offset from rip. Signed-off-by: Mathieu Desnoyers <[email protected]> Acked-by: "Paul E . McKenney" <[email protected]> Cc: <[email protected]> # v4.18 Cc: Shuah Khan <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Joel Fernandes <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Dave Watson <[email protected]> Cc: Will Deacon <[email protected]> Cc: Andi Kleen <[email protected]> Cc: [email protected] Cc: "H . Peter Anvin" <[email protected]> Cc: Chris Lameter <[email protected]> Cc: Russell King <[email protected]> Cc: Michael Kerrisk <[email protected]> Cc: "Paul E . McKenney" <[email protected]> Cc: Paul Turner <[email protected]> Cc: Boqun Feng <[email protected]> Cc: Josh Triplett <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Ben Maurer <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Linus Torvalds <[email protected]> Signed-off-by: Shuah Khan (Samsung OSG) <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- tools/testing/selftests/rseq/param_test.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) --- a/tools/testing/selftests/rseq/param_test.c +++ b/tools/testing/selftests/rseq/param_test.c @@ -56,15 +56,13 @@ unsigned int yield_mod_cnt, nr_abort; printf(fmt, ## __VA_ARGS__); \ } while (0) -#if defined(__x86_64__) || defined(__i386__) +#ifdef __i386__ #define INJECT_ASM_REG "eax" #define RSEQ_INJECT_CLOBBER \ , INJECT_ASM_REG -#ifdef __i386__ - #define RSEQ_INJECT_ASM(n) \ "mov asm_loop_cnt_" #n ", %%" INJECT_ASM_REG "\n\t" \ "test %%" INJECT_ASM_REG ",%%" INJECT_ASM_REG "\n\t" \ @@ -76,9 +74,16 @@ unsigned int yield_mod_cnt, nr_abort; #elif defined(__x86_64__) +#define INJECT_ASM_REG_P "rax" +#define INJECT_ASM_REG "eax" + +#define RSEQ_INJECT_CLOBBER \ + , INJECT_ASM_REG_P \ + , INJECT_ASM_REG + #define RSEQ_INJECT_ASM(n) \ - "lea asm_loop_cnt_" #n "(%%rip), %%" INJECT_ASM_REG "\n\t" \ - "mov (%%" INJECT_ASM_REG "), %%" INJECT_ASM_REG "\n\t" \ + "lea asm_loop_cnt_" #n "(%%rip), %%" INJECT_ASM_REG_P "\n\t" \ + "mov (%%" INJECT_ASM_REG_P "), %%" INJECT_ASM_REG "\n\t" \ "test %%" INJECT_ASM_REG ",%%" INJECT_ASM_REG "\n\t" \ "jz 333f\n\t" \ "222:\n\t" \ @@ -86,10 +91,6 @@ unsigned int yield_mod_cnt, nr_abort; "jnz 222b\n\t" \ "333:\n\t" -#else -#error "Unsupported architecture" -#endif - #elif defined(__ARMEL__) #define RSEQ_INJECT_INPUT \
