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 <mathieu.desnoyers@xxxxxxxxxxxx> Acked-by: "Paul E . McKenney" <paulmck@xxxxxxxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> # v4.18 Cc: Shuah Khan <shuah@xxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Joel Fernandes <joelaf@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Dave Watson <davejwatson@xxxxxx> Cc: Will Deacon <will.deacon@xxxxxxx> Cc: Andi Kleen <andi@xxxxxxxxxxxxxx> Cc: linux-kselftest@xxxxxxxxxxxxxxx Cc: "H . Peter Anvin" <hpa@xxxxxxxxx> Cc: Chris Lameter <cl@xxxxxxxxx> Cc: Russell King <linux@xxxxxxxxxxxxxxxx> Cc: Michael Kerrisk <mtk.manpages@xxxxxxxxx> Cc: "Paul E . McKenney" <paulmck@xxxxxxxxxxxxxxxxxx> Cc: Paul Turner <pjt@xxxxxxxxxx> Cc: Boqun Feng <boqun.feng@xxxxxxxxx> Cc: Josh Triplett <josh@xxxxxxxxxxxxxxxx> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx> Cc: Ben Maurer <bmaurer@xxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> --- Changes since v1: - Update email address for Shuah Khan based on updated MAINTAINERS email address, - Rebase on v4.19-rc5. --- tools/testing/selftests/rseq/param_test.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/tools/testing/selftests/rseq/param_test.c b/tools/testing/selftests/rseq/param_test.c index 642d4e12abea..eec2663261f2 100644 --- 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(__s390__) #define RSEQ_INJECT_INPUT \ -- 2.17.1
