Re: [PATCH] rseq/selftests: fix parametrized test with -fpie
From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: 2018-09-25 17:39:46
Also in:
linux-kselftest, lkml, stable
----- On Sep 18, 2018, at 9:53 AM, Mathieu Desnoyers mathieu.desnoyers@efficios.com wrote:
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.
Should this fix go through tip or the selftests tree ? Thanks, Mathieu
quoted hunk ↗ jump to hunk
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: <redacted> # v4.18 Cc: Thomas Gleixner <redacted> Cc: Joel Fernandes <redacted> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Watson <redacted> Cc: Will Deacon <redacted> Cc: Shuah Khan <redacted> Cc: Andi Kleen <redacted> Cc: linux-kselftest@vger.kernel.org Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Chris Lameter <redacted> Cc: Russell King <redacted> Cc: Michael Kerrisk <redacted> Cc: "Paul E . McKenney" <redacted> Cc: Paul Turner <redacted> Cc: Boqun Feng <redacted> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ben Maurer <redacted> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> --- tools/testing/selftests/rseq/param_test.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-)diff --git a/tools/testing/selftests/rseq/param_test.cb/tools/testing/selftests/rseq/param_test.c index 615252331813..4bc071525bf7 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(__ARMEL__) #define RSEQ_INJECT_INPUT \ -- 2.11.0
-- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com